Tool Materials

These Super alloys sustain its strength at high temperature and pressure conditions. Such materials have great demand in aerospace industry, marine industry, and nuclear power plants. It is particularly used in the hot sections like engines, because of their high strength and corrosion resistance at high temperature and pressure but they are the most difficult to machine materials. Their high strength possesses large amount of heat generation while machining, which reduce life of tool. Strain rate sensitivity, work hardening and precipitation hardening of material leads to more tool wear. Surface integrity obtain while machining of superalloys is poor. Poor surface finish and high residual stresses are the main causes of failure of these material components. Cutting fluid apply at high pressure in chip forming zone. It affects environment and create problem of disposal of cutting fluid. So dry machining should be employed. This article is about the difficulties occurs during dry mac...

The high strength to density ratio of titanium alloys coupled with excellent corrosion resistance even at elevated temperatures make them ideal for aerospace applications. Moreover, the biocompatibility of titanium also enables its widespread use in the biomedical and food processing industries. However, the difficulty in machining titanium and its alloys along with the high cost of its extraction from ore form presents a major economic constraint. In the context of machining economics, the wear map approach is very useful in identifying the most suitable machining parameters over a feedrate-cutting velocity plane. To date, wear maps have only been prepared for the machining of ferrous alloys. In this article, a review of the machinability of Ti-6Al-4V alloy is presented with emphasis on comparing the wear performance of various tool materials. In addition, a new wear map for Ti-6Al-4V alloy is presented based on unified turning tests using H13A grade carbide inserts. This wear map can be used as a guide in the selection of cutting variables that ensure the least tool wear rates. This article contrasts the occurrence of a safety zone in the case of machining steels to that of an avoidance zone for Ti-6Al-4V alloy.

Manufacturing yield is stable when the technology is mature. But, once in a while, excursions may occur due to variances in the large number of tools, materials, and people involved in the complex IC fabrication. Quickly identifying and correcting the root causes of yield excursions is extremely important to achieving consistent, predictable yield, and maintaining profitability. This paper presents a case study of yield learning through a layout-aware advanced scan diagnosis tool to resolve a significant yield excursion for an IC containing 1 Million logic gates, manufactured at 130 nm technology node.

Evolutionary systems have been used in a variety of applications, from turbine design to scheduling problems. The basic algorithms are similar in all these applications, but the representation is always problem specific. Unfortunately, the search time for evolutionary systems very much depends on efficient codings, using problem specific domain knowledge to reduce the size of the search space. This paper describes an approach, where the user only specifies a very general, basic coding that can be used in a larger variety of problems. The system then learns a more efficient, problem specific coding. To do this, an evolutionary system with variable length coding is used. While the system optimizes an example problem, a meta process identifies successful combinations of genes in the population and combines them into higher level evolved genes. The extraction is repeated iteratively, allowing genes to evolve that have a high level complexity and encode a high number of the original, basic genes. This results in a continuous restructuring of the search space, allowing potentially successful solutions to be found in much shorter search time. The evolved coding can then be used to solve other, related problems. While not excluding any potentially desirable solutions, the evolved coding makes knowledge from the example problem available for the new problem. The paper shows an example from the domain of two-dimensional shape designs. In this example, a coding is evolved that uses 366 evolved gene, encoding on average 17 basic genes. The evolved coding is successfully used to optimize a room layout, where the original coding converges to a local maximum in fitness and therefore does not find any feasible solutions.

The objective of this research was to investigate a new test procedure for simulating the temperatures in die casting so that materials can be evaluated as tool materials for the high-pressure die casting of aluminium. Other procedures have been used for evaluating the thermal fatigue performance of tool materials, but these tests do not reproduce all the conditions found in production environments. A new test method has been established that enables the thermal fatigue resistance of materials to be identified. The test is robust, reliable, and versatile and has a large operating temperature range (25-1200 ˚C), and the cycle times and dwell times are adjustable. The results have shown a similar number of cycles to induce the same level of fatigue cracking as in actual die-casting tools. The performance of different materials can be compared, and an approximate fatigue life for high-pressure die-casting tools can be determined.

Electrical discharge machining (EDM) is an important process in the field of micro machining. However, a number of issues remain to be solved in order to successfully implement it in an industrial environment. One of these issues is the processing time. This paper investigates the optimisation of machining parameters for rough and fine machining in micro EDM. In one case, the parameters are selected to achieve the highest material removal rate (MRR). In the other case, the best surface roughness is targeted. Some of the main difficulties linked with micro EDM are caused by the high wear occurring on the electrode. The study focuses on a specific combination of electrode and workpiece material and proposes a typical method for micro EDM process optimisation.

An experimental investigation is planned in order to study the machinability of Inconel 718 with silicon carbide whisker reinforced ceramic inserts in end milling process. The relationship between the cutting speed, feed rate, and depth of cut against the response factors are studied to show the level of significance of each parameter. The cutting parameters are optimized by using Taguchi method. Implementing analysis of variance, the parameter which influences the surface roughness the most is determined to be the cutting speed, followed by the feed rate and depth of cut. Meanwhile, the optimal cutting condition is determined to have high cutting speed, low feed rate, and high depth of cut in the range of selected parameters.

One of the most important components of a tube end flaring machine is the flanging tool, which is subjected to mechanical stresses such as compression, bending and abrasion. It is therefore very important to choose the optimal material and manufacturing technology for the flanging tool. Böhler tool steel grades K110 and K340 were chosen as the subject of our research. Both materials were used to produce tube flanging tools, which were subjected to hardness testing, microscopic examination and surface wear testing after simple cooling or deep cooling and triple high temperature tempering after austenitisation in a vacuum at elevated temperature. Based on the measurements, the deep cooled and triple tempered K340 steel was found to be the most favourable tool steel for the production of the tube flanging tool.

Mobile agents are a useful paradigm for network coding providing many advantages and disadvantages. Unfortunately, widespread adoption of mobile agents has been hampered by the disadvantages, which could be said to outweigh the advantages. There is a variety of ongoing work to address these issues, and this is discussed. Ultimately, genetic algorithms are selected as the most interesting potential avenue. Genetic algorithms have many potential benefits for mobile agents. The primary benefit is the potential for agents to become even more adaptive to situational changes in the environment and/or emergent security risks. There are secondary benefits such as the natural obfuscation of functions inherent to genetic algorithms. Pitfalls also exist, namely the difficulty of defining a satisfactory fitness function and the variable execution time of mobile agents arising from the fact that it exists on a network. DNAgents 1.0, an original application of genetic algorithms to mobile agents is implemented and discussed, and serves to highlight these difficulties. Modifications of traditional genetic algorithms are also discussed. Ultimately, a combination of genetic algorithms and artificial life is considered to be the most appropriate approach to mobile agents. This allows the consideration of agents to be organisms, and the network to be their environment. Towards this end, a novel framework called DNAgents 2.0 is designed and implemented. This framework allows the continual evolution of agents in a network without having a seperate training and deployment phase. Parameters for this new framework were defined and explored. Lastly, an experiment similar to DNAgents 1.0 is performed for comparative purposes against DNAgents 1.0 and to prove the viability of this new framework. In perfect honesty figuring out how to sufficiently thank everyone peripherally involved in this endeavor in anything less than a book length manuscript is incredibly difficult. Certainly if I named everyone involved, it would simply be impossible. There is one name that must be mentioned of course; without the assistance of Dr. Dia Ali this work would have never been undertaken. There is no way to quantify the myriad ways in which he has assisted and guided this effort. I am also thankful to my committee for going above and beyond the call of duty in helping me refine these ideas. My colleagues in Tec 251, past and present, were also of great help. Indeed, some of them were largely responsible for my initial decision to pursue graduate school. On a more personal note, my family has, despite changes and hardships during this process, been extremely supportive of this decade-long detour from life called College. I owe them more than can ever be said. In particular, I am grateful to my grandmother. Although she did not live to see this work, she never doubted that I would ultimately be successful. Lastly, there are many friends who had to put up with tangential conversations. These conversations lead to more insights than you know, so you did not suffer in vain. You all know who you are, and have my sincere thanks.

Low electrode wear EDM is attained by the adhesion of heat resolved carbon made from kerosine type machining fluid to the electrode end surface. This phenomenon, however, occurs only under long pulse duration. Therefore, the low electrode wear EDM under finishing condition is impossible so far. In the previous paper, the authors developed a turbostratic carbon electrode whose structure is very similar to the heat resolved carbon generated in EDM process and made it clear that the low electrode wear EDM was possible by using the electrode even under finishing condition. In this study, a carbon coated electrode and a SiC coated one which can be made rapidly at low cost were developed and their EDM characteristics were investigated. Experimental analysis pointed it out that both electrodes were effective in reducing electrode wear under finishing condition

Resin cure shrinkage and anisotropic thermal expansion cause process induced residual stresses in polymer composites. When relieved, the residual stresses cause reduction in enclosed angles of composite laminates; a phenomenon often called spring-in. Spring-in compromises the dimensional ®delity of composite parts and is often accounted for when designing the tool the part is made on. Spring-in is often estimated using past experience or simple analytical formulas that ignores many process parameters affecting the spring-in. This paper presents an experimental study that shows that spring-in can be strongly affected by a number of factors such as cure cycle, tool surface, part geometry, and lay-up. The paper also shows that by developing material models that accurately represent the stress transfer between the part and the tool at the tool-part interface, and by implementing a large deformation solution technique, the experimental results observed in this study can be predicted using ®nite element based process models.

Surface quality is one of the most impellent customer requirements in machining. The main aspect of surface quality on machined parts is probably surface integrity, such as roughness and residual stresses. In particular, residual stresses in the machined surface and subsurface are affected by tool geometry, material and machining parameters. These residual stresses can have significant effects on the service quality and the component life; they can be determined by either empirical or numerical investigations for the selected configurations; however, they are expensive procedures. The problem becomes more difficult if the aim is the inverse determination of the cutting conditions which correspond to a requested residual stress profile, inside the machined material. This paper presents a predictive hybrid model based on the artificial neural networks (ANNs) and finite element method (FEM) that can be used for both forward and inverse prediction. The former is able to determine a residual stresses profile corresponding to a given tool, material and process conditions, the latter is able to determine these conditions when a constraint on the residual stresses distribution is given. Three layer neural networks were trained basing on selected data from numerical investigations on hard machining of 52100 bearing steel, and then validated with data obtained by experiments. Prediction errors range between 4% and 16% for the whole data set, both for forward analysis and inverse process design, showing that this hybrid ANN-FEM based approach provides a robust framework for 52100 machining analysis.

In the mass production of automotive parts, the tool life of the manufacturing tool is very important from an economic site. The tool life is determined by the material quality and the properties of the tool achieved by heat treatment. Böhler K340 Isodur grade tool steel is considered one of the best cold forming tool steels due to its chemical composition and its electro-slag remelting manufacturing. In our experiments, samples made from this steel were subjected to two different heat treatment technologies. The first one (CT-conventional treatment) was tempered three times at high temperature after high temperature hardening, and the second one (DCT-deep cryogenic treatment) was deep frozenwith nitrogenafter high temperature hardening and then tempered three times at high temperature. After the heat treatment, the pieces were subjected to microscopic, toughness, hardness and wear tests. The results of the measurements showed that the structure of the DCT steel is much finer and more homogeneous than the CT steel, the impact strength is higher, there is no difference in hardness, but the wear resistance of the CDP specimen is better than the CT specimen.

Electrical Discharge Machining is one of the non-conventional material removal process. It is widely used for manufacturing complex materials parts which are difficult to be machined by conventional manufacturing processes. It is based on thermoelectric energy between workpiece and electrode. Due to spark occurs in the gap between electrode and workpiece, metal is removed by melting and vaporizing. Workpiece and electrode must have electrically conductive to generate a spark. The performance of the EDM process is largely depends on the electrode. Electrode is considered as tool in EDM process. Selection of the electrode material plays vital role in the EDM process. Different electrode materials have different properties. Hence, the performance of the EDM process changes with different materials. Researchers have used different materials as electrode to investigate the effects of materials and to improve the performance of EDM process. This paper reviews the research work carried out in the field of materials and manufacturing methods for electrodes in EDM process.

Electrical Discharge Machining is one of the non-conventional material removal process. It is widely used for manufacturing complex materials parts which are difficult to be machined by conventional manufacturing processes. It is based on thermoelectric energy between workpiece and electrode. Due to spark occurs in the gap between electrode and workpiece, metal is removed by melting and vaporizing. Workpiece and electrode must have electrically conductive to generate a spark. The performance of the EDM process is largely depends on the electrode. Electrode is considered as tool in EDM process. Selection of the electrode material plays vital role in the EDM process. Different electrode materials have different properties. Hence, the performance of the EDM process changes with different materials. Researchers have used different materials as electrode to investigate the effects of materials and to improve the performance of EDM process. This paper reviews the research work carried out in the field of materials and manufacturing methods for electrodes in EDM process.

The high strength to density ratio of titanium alloys coupled with excellent corrosion resistance even at elevated temperatures make them ideal for aerospace applications. Moreover, the biocompatibility of titanium also enables its widespread use in the biomedical and food processing industries. However, the difficulty in machining titanium and its alloys along with the high cost of its extraction from ore form presents a major economic constraint. In the context of machining economics, the wear map approach is very useful in identifying the most suitable machining parameters over a feedrate-cutting velocity plane. To date, wear maps have only been prepared for the machining of ferrous alloys. In this article, a review of the machinability of Ti-6Al-4V alloy is presented with emphasis on comparing the wear performance of various tool materials. In addition, a new wear map for Ti-6Al-4V alloy is presented based on unified turning tests using H13A grade carbide inserts. This wear map can be used as a guide in the selection of cutting variables that ensure the least tool wear rates. This article contrasts the occurrence of a safety zone in the case of machining steels to that of an avoidance zone for Ti-6Al-4V alloy.

The paper initially reviews prior work on the influence of operating parameters on tool life when milling Inconel 718. Following this review, experimental work is described which evaluates the effect of varying feed rate/chip thickness, immersion ratio (radial depth of cut), tool material and geometry on the tool life, tool wear and productivity obtained when end milling Inconel 718. The experimental work was conducted in two phases. The first phase used a fixed tool material and geometry to examine the effects of various feed rates and radial depth's of cut. In the second phase, a reduced number of parameters were examined but various different tool materials and geometries were utilized. The results showed that no single tool material or geometry gave the best overall performance. However, areas were identified in which a specific combination of tool material and geometry was superior. The findings of this work can be used to optimise productivity depending on the volume of material to be removed.

Inconel 718 is one of a family of nickel based superalloys that are used extensively by the aerospace industry in the hot sections of gas turbine engines. The literature detailing the effects of varying operating parameters on tool life when machining nickel based superalloys is comprehensive, however, relatively little of this data refers to their effects on machined workpiece surface integrity and residual stress generation. Greater knowledge of the effects of operating parameters on surface integrity is critical to the acceptance of new cutting tool materials, tool geometries and strategies. The paper initially reviews prior work on the surface integrity achieved when turning Inconel 718. Following on from this a series of experiments evaluating the effects of varying cutting tool material, geometry, wear level and operating parameters are detailed. The results show that the largest influence on surface integrity was tool wear. Cutting with a worn tool resulted in greater microstructural deformation, microhardness changes and high surface tensile stresses. High tensile stresses were also formed in the surface layer when cutting with a coated tool, while cutting with an uncoated tungsten carbide insert at the same operating parameters produced deep compressive stresses beneath a reduced tensile layer.

This work presents a comparative study of the surface characteristics of spur gears produced from cryotreated and untreated hobs at various cutting speeds and feed rates keeping constant depth of cut. Furthermore, a Taguchi Grey Relational Analysis was used to optimize the hobbing process and ANOVA was conducted to analyze the influence of studied parameters. The experimental run, for which the highest gray relational grade was obtained, was considered the optimal cutting condition. The results revealed that cryogenic treatment of the hob significantly decreased the spur gear's flank surface roughness (R a andR max) and microgeometric deviations (F a; F β ; F p andF r). The optimization results revealed that a cutting speed of 400 rpm and a feed of 8 mm/min with a cryo-treated hob produced the best surface characteristics (i.e.R a ¼ 0:30μ m; R max ¼ 2:77μ m; F a ¼ 10:60μ m; F β ¼ 20:03μ m; F p ¼ 10:40μ mandF r ¼ 20:20μ m). This study can assist manufacturing industries in selecting suitable operating parameters for obtaining highquality gears.

Demand for miniaturized parts with tight geometrical tolerances and superior surface finish has been increasing. Development of micromachining processes has enabled adaptation of miniaturized parts and products in mechanical systems. Machining at the microscale level has supplementary challenges like high cutting forces, reduced tool life, and damaged machined surfaces. Catastrophic failure of microtools is notable problem, if tool deflection increases significantly. Therefore, incorporating tool life improvement measures are essential to minimize tool replacement cost and also to achieve efficient cutting at micro-level. Cryotreatment imparts better physical properties to cutting tools. In the present work, effects of different cryogenic treatment parameters on micro tungsten carbide-cobalt (WC-Co) end mill cutters and its performance while machining Ti-6Al-4V have been investigated. The metallurgical changes imparted to cutting tool by cryotreatment are studied via micro-hardness test along with EDS, SEM and XRD methods. It is found that all cryotreated tools have higher hardness compared to untreated tools. Additional h (eta) carbide formation has been clearly observed for the tools soaked for 24 h, moreover a variation in other phase of WC is also observed for different set of cryotreatment. Machining process is significantly affected by the low thermal conductivity of Ti-6Al-4V. In case of untreated micro-milling tool, abrasive wear is dominant, whereas built-up-edge affected the performance of cryotreated tools at shallow cryotreatment temperatures for 8-16 h soaking time. Deep cryotreated tool (at 24 h soaking time) performed better in terms of cutting force and surface roughness due to retainment of sharp cutting edge.

Under the concept of "Industry 4.0", production processes will be pushed to be increasingly interconnected, information based on a real time basis and, necessarily, much more efficient. In this context, capacity optimization goes beyond the traditional aim of capacity maximization, contributing also for organization's profitability and value. Indeed, lean management and continuous improvement approaches suggest capacity optimization instead of maximization. The study of capacity optimization and costing models is an important research topic that deserves contributions from both the practical and theoretical perspectives. This paper presents and discusses a mathematical model for capacity management based on different costing models (ABC and TDABC). A generic model has been developed and it was used to analyze idle capacity and to design strategies towards the maximization of organization's value. The trade-off capacity maximization vs operational efficiency is highlighted and it is shown that capacity optimization might hide operational inefficiency.

The trend of micro-manufacturing has been increasing from last decade. Researcher realized the need of non-MEMS (Micro electro-mechanical system) techniques due to the limitation of MEMS such as, types of material processing and manufacturing of complex three dimensional components. Now days mechanical micro cutting is the preferred manufacturing process for the production of various micro-components. Micro-cutting has potential to overcome the limitations of non-MEMS techniques, however the short tool life of micro tool is the big challenge to improve micro-cutting process and manufacturing cost. The conventional tool life improvement techniques have some limitation in micro-cutting. Therefore in the present work, cryogenic treatment (CT) has been used to treat tungsten carbidecobalt (WC-Co) end mills. To study the effect of cryotreatment metallurgical characterisation carried out by various tests. Moreover the performance of cryotreated tool evaluated by measuring cutting force, surface roughness and tool wear while machining titanium material. It is found the DCT (deep cryotreated tool) for 20 hr performed good in terms of cutting force and surface roughness.

In this study, it was aimed to investigate the effect of subzero heat treatment duration as well as tempering on some microstructural and mechanical properties of commercial Calmax cold work tool steels. Firstly, five steel samples were austenitized at 960C following by quenching at 170°C and one of them was remained as just quenched for reference. After quenching, one of other four samples was tempered at 525°C for 30 min, while two of four samples were exposed to subzero heat treatment in liquid nitrogen medium having -197°C for 15 and 60 min, respectively and last sample was subjected to subzero heat treatment for 60 min. and then tempered at 525°C for 30 min. The hardness of quenched, quenched and tempered, quenched and subzero heat treated and quenched, subzero heat treated and tempered test materials were determined as 755, 527, 807, 829, 616 HV(0.1), respectively. The microstructure of test samples investigated by Scanning electron microscopy was mainly consisting of martensi...

This paper discusses the advances of axiomatic design, both as a design approach in industry and as a research field. It is demonstrated that the growth is based on industrial practice and a vision of design theory. The information presented in this paper is based on experience from implementation of axiomatic design in industry in Asia, the USA, and Europe. Specifically, this paper presents strategic implications of implementing a new design method within a company, two generic implementation approaches, risks and benefits of each approach based on actual implementation cases, and some examples of products developed by industry by using axiomatic design. The paper also points out the importance of continued teaching and research in the area of axiomatic design. It outlines a typical course for industry given at MIT and presents issues for future research.

Objective: To determine the relationship of bone marrow lesions (BMLs) with phenomena such as clinical symptoms, histological subchondral bone damage, and development of osteoarthritis, a reliable and reproducible method to localize and quantify BMLs accurately is indispensable. Therefore, the goal of the current study was to develop and validate a novel semiautomated segmentation method based on the KNN classification technique on T2-weighted (T2w) SPIR and proton density-weighted (PDw) magnetic resonance images (MRIs), as this would provide an accurate, reliable, and reproducible tool. Materials and Methods: Twenty PDw and T2w SPIR MRIs were selected and manually segmented as a learning set for the software system. The manual segmentations were considered the gold standard. Automated segmentation based on the KNN classification technique was carried out on the same MRIs. To determine the accuracy and validity of the system, the automated segmentations were compared to the gold standard using the Dice Similarity Index (DSI). Results: The KNN classification system resulted both visually and statistically in an accurate segmentation of BMLs on T2w SPIR MRIs with an excellent mean optimal DSI of 0.702 (±0.202; range, 0.409-0.908). Elimination of specific areas smaller than 10 voxels improved the accuracy. The accuracy was independent of BML size. The segmentation of BMLs on PDw MRIs was less reliable with a mean optimal DSI of 0.536 (±0.156). Conclusion: Although the applicability of this method is limited on PDw MRIs, the KNN classification system provides an accurate, reliable, and reproducible tool for semiautomated segmentation of BMLs in T2w SPIR MRIs of the knee.

Recently, a non-conventional machining technique known as ultrasonically assisted turning (UAT) was introduced to machine modern alloys, in which low-energy, highfrequency vibration is superimposed on the movement of a cutting tool during a conventional cutting process. This novel machining technique, results in a multi-fold decrease in the level of cutting forces with a concomitant improvement in surface finish of machined modern alloys. Also, since the late 20 th century, machining of wear resistant materials that soften when heated have been carried out with hot machining techniques. Turning (HUAT) is introduced for the processing of a Ti-based alloy. In this technique, UAT is combined with a traditional hot machining technique to gain combined advantages of both schemes for machining of intractable alloys. HUAT of the Ti alloy was analysed experimentally and numerically to demonstrate the benefits in terms of reduction in the cutting forces and improvement in surface roughness over a wide range of industrially relevant speed-feed combinations for titanium alloys.

This paper presents the investigation on generation of square shape cavities with solid and bundled tool electrodes. The workpiece and tools material are AISI 304 and electrolytic copper respectively. Effect of peak current and pulse on time has been observed on machining performance in terms of material removal rate and tool wear rate. Three different levels of peak current and five levels of pulse on time have been selected for investigation. To remove the un-machined pinned shape structure of workpiece, 1mm orbital radius has been given to both the electrodes. Experiments have been designed using fractional factorial design. The experimental results indicate that solid tool yields 45% more material removal rate than bundled tool electrode and TWRfor both tool is decreasing with pulse on time.

CK45 steel is a suitable material for the manufacturing of forging dies. This paper investigates the influence of electrical discharge machining (EDM) parameters including voltage, current, on-time and off-time on the microstructure of the machined surface of this material. The process induces thermal stresses that in turn result in the generation of widespread micro-cracks on the surface of the part subjected to spark EDM. The influence of EDM parameters on the quality of the machined surface is explored by performing an extensive experimental program. The impact of EDM parameters on the surface roughness and the intensity of micro-cracks have been evaluated quantitatively using the test results and regression analysis. Predicting the relationship between EMD parameters and the surface quality provides practical means to appropriately decide on the adjustment of process control parameters to their optimum values and hence to achieve the desired surface quality at reasonable manufac...

The test results presented in this chapter concern formation of the quasi-composite MMCs structure on the surface of elements from aluminium cast alloys AC-AlSi9Cu and AC-AlSi9Cu4 by fusion of the carbide or ceramic particles WC, SiC, ZrO 2 and Al 2 O 3 in the surface of alloys. In addition, within the scope of the tests the phase transformations and precipitation processes present during laser remelting and fusion at appropriately selected parameters: laser power, the rate of fusion and quantity of the ceramic powder fed have been partially examined. Design/methodology/approach: In general, the laser surface processing should result in achievement of the surface layer with the most favourable physical and mechanical properties, in particular enhancement of surface hardness, improvement of abrasion resistance and resistance to corrosion is assumed in relation to the selected aluminium alloys after standard thermal processing. Findings: The presented results of the surface layer include analysis of the mechanisms responsible for formation of the layer, and particularly concern remelting of the substrate and its crystallisation at various parameters of the High Power Diode Laser (HPDL) and the technological conditions of the surface processing, remelting and fusion of the particles in the surface of cast alloys ACAlSi9Cu and ACAlSi9Cu4. For the purpose of testing the structure of the obtained surface layers the test methods making use of the light microscopy method supported with computer image analysis, transmission and scanning electron microscopy, X-ray analysis, X-ray microanalysis, as well as methods for testing the mechanical and usable properties have been used. Practical implications: What is more, development of the technology of surface refinement of cast alloys Al-Si-Cu with the laser fusion methods will allow for complex solving of the problem related to enhancement of the surface layer properties, taking into account both economic and ecological aspects. Originality/value: On the basis of the test result analysis it has been pointed out that in case of the analysed aluminium cast alloys the applied laser surface processing, and the thermal processing preceding it, ensuring occurrence of the mechanisms responsible for material strengthening, enable enhancement of the mechanical and usable properties of the examined alloys. An essential objective is also to indicate the multiple possibilities for continuation of the tests, regarding the light metal alloys aluminium, magnesium and titanium, broadening the current knowledge within the scope of elements and light structures.

In this paper was presented the investigations results concern the influence of laser feeding on the structure and mechanical properties of aluminium alloy . The goal of this investigations was to improve wear resistance and mechanical properties of the surface layers of the aluminium alloy by the laser feeding of the aluminium alloy by the hard silicon carbide particles. The SiC powder has been introduced in the liquid metal using gravity feeder at a constant rate of 1 g/min. In order to remelting the aluminium alloy surface, there has been used the high power diode laser HPDL, with an applied power of the laser beam in the range between 1.6 kW and 2.0 kW. The linear laser scan rate of the beam was set as much as 0.4 m/min. As a result of laser feeding of aluminium alloy a composite layer with greater hardness and wear resistance compared to the based material has been obtained.

The purpose of this research paper is focused on the 55NiCrMoV7, 32CrMoV12-28, X40CrMoV5-1, X38CrMoV5-3 hot work tool steels surface layers improvement properties using HPDL laser. The paper present laser surface technologies, investigation of structure and properties of the hot work tool steels alloying with ceramic particles using high power diode laser HPDL. Design/methodology/approach: Investigation indicate the influence of the alloying carbides on the structure and properties of the surface layer of investigated steel depending on the kind of alloying carbides and power implemented laser (HPDL). Laser alloying of surface layer of investigated steel without introducing alloying additions into liquid molten metal pool, in the whole range of used laser power, causes size reduction of dendritic microstructure with the direction of crystallization consistent with the direction of heat carrying away from the zone of impact of laser beam. Findings: In the effect of laser alloying with powders of carbides NbC, TaC, TiC, WC and VC occurs size reduction of microstructure as well as dispersion hardening through fused in but partially dissolved carbides and consolidation through enrichment of surface layer in alloying additions coming from dissolving carbides. Introduced particles of carbides and in part remain undissolved, creating conglomerates being a result of fusion of undissolved powder grains into molten metal base. In effect of convection movements of material in the liquid state, conglomerates of carbides arrange themselves in the characteristic of swirl. Remelting of the steel without introducing into liquid molten pool the alloying additions in the form of carbide powders, causes slight increase of properties of surface layer of investigated steel in comparison to its analogical properties obtained through conventional heat treatment, depending on the laser beam power implemented for remelting. Practical implications: It has the important cognitive significance and gives grounds to the practical employment of these technologies for forming the surfaces of new tools and regeneration of the used ones. The increase of hardness of surface layer obtained throughout remelting and alloying with carbides by high power diode laser is accompanied by increase of tribological properties, when comparing to the steel processed with conventional heat treatment. Originality/value: The outcome of the research is an investigation and proving the structural mechanisms accompanying laser remelting and alloying. The artificial neural networks were used to determine the effect of the technological effect of laser alloying on hardness and resistance wear abrasion of the hot work tool steels.

The purpose of the chapter is to present a methodological concept allowing to demonstrate the development directions of materials surface engineering according to the level of generality and the intensity of the phenomena analysed on other phenomena. Design/methodology/approach: A set of analytical methods and tools was used to present the development directions of materials surface engineering at the three levels analysed, i.e.: a macro-, meso-and microlevel. The analytical methods and tools comprise the scenario method, artificial neural networks, Monte Carlo method, e-Dephix method, statistical lists as bar charts, foresight matrices together with technology development tracks, technology roadmaps, technology information sheets and the classical materials science methods. Findings: A research methodology allowing to combine a presentation and description of the forecast future events having a varied level of generality and capturing the cause and effect relationships existing between the events. The methodological concept discussed, implemented with reference to materials surface engineering, has a much broader meaning, and can be successfully applied in other technology foresights, and also in industrial and thematic foresights after minor modifications. Practical implications: The outcomes of the research conducted may be and should be used in the process of creating and managing the future of materials surface engineering and, within the time horizon of 20 years, may and should influence positively the development of the economy based on knowledge and innovation, sustainable development and the statistical level of the technologies used in industry, especially in small-and medium-sized enterprises. 13 Materials surface engineering development trends Neural networks aided future events scenarios presented on the example of laser surface treatment 523 Originality/value: An own methodological concept constitutes an original way of presenting the development directions of the investigated field of knowledge. The use of neural networks represents an innovative and experimental approach unseen in foresight methodology to date.

Purpose: There are presented in this paper the investigation results of microstructure of the cast aluminium alloys in the as cast state as well after laser treatment used for alloying with carbide and oxide ceramic powders like aluminium oxide and silicon carbide, titanium carbide, vanadium carbide and tungsten carbide. The purpose of this work was also to determine the laser treatment conditions for surface hardening of the investigation alloys, like laser power, as well the laser scan rate. Design/methodology/approach: The investigations were performed using light and electron microscopy for the microstructure determination. By mind of the transmission electron microscopy, especially selected area diffraction method appliance it was possible to determine the phases occurred in the alloy in the as cast state. The morphology and size of the Mg 2 Si was also possible to determine as well the lattice parameters for this phase. Findings: Concerning the laser treatment conditions for surface hardening the scan rat as well as the laser power influence was studied. It was used a power in the range between 1.0 and 2.0 kW The structure of the surface laser tray changes in a way, that there are very high roughness of the surface zone and the flatness or geometry changes in an important manner, crucial for further investigation. Research limitations/implications: The aluminium samples were examined metallographically using optical microscope with different image techniques as well as transmission electron microscope. Practical implications: Developing of new technology with appliance of Al alloys, High Power Diode Laser and diverse ceramic powders can be possible to obtain, based in findings from this research project. Some other investigation should be performed in the future, but the knowledge found in this research concerning the proper process parameters for each type of alloy shows an interesting investigation direction. Originality/value: The combination of metallographic investigation for cast aluminium alloys -including electron microscope investigation -and HPDL treatment parameters makes the investigation very attractive for automobile, aviation industry, and others where aluminium alloys plays an important role.

The reason of this work was to determine the thermal fatique resistance, the laser treatment parameters, particularly the laser power, to achieve a high value of layer hardness for protection of this hot work tool steel from losing their work stability and to make the tool surface more resistant for work. The purpose of this work was also to determine technological and technical conditions for remelting the surface layer with HPDL. Design/methodology/approach: In this paper the results of new laser treatment techniques applied in metal surface technology are presented and discussed. There is presented laser treatment with remelting of hot work tool steel 32CrMoV12-28 with ceramic powders especially carbide -WC, as well as results of laser remelting influence on structure and properties of the surface of the hot work steel, carried out using the high power diode laser (HPDL). Special attention was devoted to monitoring of the layer morphology of the investigated material and on the particle occurred. Optical and scanning electron microscopy was used to characterize the microstructure and intermetallic phases occurred. Findings: The layer is without cracks and defects as well as has a considerably higher hardness value compared to the non remelted material. The hardness value increases according to the laser power used so that the highest power applied gives to highest hardness value in the remelted layer. The results present only four choused laser powers by one process speed rate. Also one powder in form of WC was used for alloying with the particle size of 10µm. Originality/value: The originality of this work is based on applying of High Power Diode Laser for improvement of steel mechanical properties.

The paper presents the influence of alloying with NbC powder by the use of a high-power diode laser and TiAlN, AlSiCrN and TiCN gradient coatings deposition by PVD process on microstructure and hardness of the X40CrMoV5-1 steel surface layer. Design/methodology/approach: Microstructure was characterised using optical metallography, scanning and transmission electron microscopy. Findings: In the effect of laser alloying with powders of carbide NbC occurs size reduction of microstructure as well as dispersion hardening through fused in but partially dissolved carbides and consolidation through enrichment of surface layer in alloying additions coming from dissolving carbides. The structure of the PVD coatings consisted of fine crystallites while their average size fitted within the range of 15-50 nm, depending on the coating type. The coatings demonstrated columnar structure. Research limitations/implications: It is necessary to continue the research to determine alloying parameters for demanded properties of hot work tool steels surface layers. Further investigations should be concentrated on the determination of the thermal fatigue resistance of the layers. Practical implications: Good properties of the PVD coatings and the laser treatment make these layers suitable for various technical and industrial applications. Originality/value: Laser alloying by using different carbide powders and HPDL laser is a new way to improve the structure and mechanical properties of the hot work tool steels.

The reason of this work was to determine the thermal fatique resistance, the laser treatment parameters, particularly the laser power, to achieve a high value of layer hardness for protection of this hot work tool steel from losing their work stability and to make the tool surface more resistant for work. The purpose of this work was also to determine technological and technical conditions for remelting the surface layer with HPDL. Design/methodology/approach: In this paper the results of new laser treatment techniques applied in metal surface technology are presented and discussed. There is presented laser treatment with remelting of hot work tool steel 32CrMoV12-28 with ceramic powders especially carbide -TaC, as well as results of laser remelting influence on structure and properties of the surface of the hot work steel, carried out using the high power diode laser (HPDL). Special attention was devoted to monitoring of the layer morphology of the investigated material and on the particle occurred. Optical and scanning electron microscopy was used to characterize the microstructure and intermetallic phases occurred. Findings: The layer is without cracks and defects as well as has a considerably higher hardness value compared to the non remelted material. The hardness value increases according to the laser power used so that the highest power applied gives to highest hardness value in the remelted layer. The results present only four choused laser powers by one process speed rate. Also one powder in form of TaC was used for alloying with the particle size of 10µm. Practical implications: The aim of this work is the determination of laser treatment technique for alloying and remelting of hot work tool steel. Originality/value: The originality of this work is based on applying of High Power Diode Laser for improvement of steel mechanical properties.

Electrical Discharge Machining (EDM) is a non-conventional cutting operation for based of materials removal to the core fact which conceder insignificant force of tool is created through the process of machining. Also, EDM used in produce hard materials that have electrical conductivity. In EDM process, the pivotal topical parameters are Material Removal Rate (MRR), Surface Roughness (Ra) and Micro Hardness (HV). The traditional try and error way to define the influence the parameters of machining on the objective parameters is time consuming as well as high cost. The aim of this work is to evolve a mathematical model using multiple regression to describe the effecting of three machining parameters (pulse on time, pulse off time and current) on the objective parameters. 27 samples were run by using computer numerical control based EDM machine which used for machining steel 304 with a dielectric solution of gas oil by using DC current values. Three predicted models have been developed using multiple regression methods show a reliable accuracy to be used in this kind of cutting process. The result of this work is helpful to be performed in the industry to decrease the time and cost in MRR, Ra & HV prediction.

The aim of this study is the investigation of micro-structural behaviour of a Mat. No. 1.2379 (EN-X160CrMoV121; AISI D2) cold work tool steel after remelting with a precise pulsed Nd:YAG laser. The investigated steel is one of the most hard to weld tool steels, due to large amount of alloying elements. The analysis was done on single spots remelted with specifi c laser pulse shape and parameters, assuring crack-less solidifi cation. Re-solidifi ed areas were investigated with microscopy, hardness measurements, X-ray spectroscopy and diff raction method. Laser treatment causes rapid solidifi cation leading into a formation of a fi ne dendritic microstructures containing high amount of retained austenite causing a signifi cant decrease of hardness.

The paper presents the results of research aimed at developing a method for hard-to-machine metal alloy milling process diagnosis using computational intelligence methods. To diagnose the process, a signal from an accelerometer mounted on the spindle of a CNC machine was used. The data were recorded during milling of Inconel 625 alloy workpieces, performed by sharp and blunt cutters. The acceleration signal metrics, both in the time and frequency domains were used to develop the classifiers. Based on the experiments, it has been demonstrated that it is possible to effectively diagnose Inconel alloy workpieces milling process using shallow computational intelligence methods (decision trees, k-NN and linear support vector machines). Python was used for data processing and visualisation as well as classifiers development and testing.

The rubber pressing process is applied for the rapid production of thermoplastic composite products. However, rubber pressed products show geometrical distortions, such as warpage, due to process-induced residual stresses. It is believed that these stresses build up as a result of the large thermal gradients that are present during consolidation. An experimental study is performed to measure the curvature after rubber pressing of initially flat woven fabric glass/PPS composite panels. A material model is proposed that incorporates the solidification of the composite in order to predict the residual stresses and the warpage due to inhomogenous cooling. The model is employed in Finite Element simulations of the rubber pressing process. The simulations are compared to the experimentally obtained curvatures. It shows that inhomogeneous cooling has a minor effect on the warpage in this case, and that another mechanism is present.

Influence of cooling fluid application on the tool wear, during longitudinal turning of hardened chrome nickel steel, on the basis of experimental investigations is presented in this paper. Cutting tool wear investigation through comparation dry machining and machining by cooling fluid application, for the same other machining conditions, are conducted. Tool wear size, tool wear shape and cutting tool life are taken into account by cutting tool wear investigation. Analysis of experimental results showed inverse proportion between coolig fluid application and flank wear size, as well as significance of influence on tool wear and its characteristics, via the flank wear shape. Also, analysis of experimental results showed significance of influence coolig fluid application on increase of cutting tool life.

Polyoxymcthylene (POM) is an extensively used engineering thermoplastic polymer. Owing to its superior properties and potential applications in numerous turfs of structural machineries, it is essential to probe the machining of POM. The economy of machining operations plays an imperative role in increasing productivity and effectiveness. The persistence of optimal cutting parameters, such as cutting speed, feed and depth of cut, which are valid for given cutting tools, is one of the dynamic segments in process planning of metal parts. This research work concerns an experimental study dealing with cutting parameters and its effects on surface roughness (Ra) and material removal rate (MRR) during the turning of POM. The approach is based on Response Surface Technology (RSM). Experiments are designed using central composite design and second-order quadratic models are developed to define the optimal machining parameters. These optimized parameters are validated experimentally.

Cryogenic treatment is a thermal treatment process in which parts are usually cooled to temperatures below −70 °C (< 203 K) to induce metallurgical changes in materials. The treatment showed a significant performance improvement in most ferrous materials and their alloys by transforming retained austenite to martensite and precipitating secondary carbides. However, the effect of such low-temperature treatment on highly stable super-hard materials such as tungsten carbide (commonly referred to as “cemented carbide”) is uncertain. However, researchers have reported the precipitation of etaphase carbides, densification of cobalt binder, refinement of tungsten carbide grains, phase transformation of cobalt, and changes in residual stress in cryogenically treated tungsten carbide (WC-Co) materials, which resulted in increased hardness and wear resistance. Hence, this paper focuses on summarizing the cryogenic treatment parameters used in different studies, the rate of performance improvement in different applications, and the reported mechanical and metallurgical changes, which would serve as a pool of knowledge for further studies.

Stellite 6 is the most generally useful cobalt alloy, having excellent resistance to many forms of mechanical and chemical degradation over a wide temperature range. Therefore, in particular, their use in aerospace projects world wide has provided confidence leading to acceptance as prime material for aerospace vehicles in recent years. This paper outlines the effectiveness of the ultrasonic machining of stellite 6 in terms of tool wear rate of the tool used and the material removal rate of work piece produced. The optimum combination of various input factors as type of abrasive slurry, their size and concentration, nature of tool material and power rating of the machine for the ductile chip formation in the machining of stellite 6 has been determined by applying the Taguchi multi-objective optimization technique and F-test. The analysis of results has been done using the statistica 7.0 software and results obtained are validated by conducting the confirmation experiments. The study shows the considerable improvement in multiple S/N ratio as compared to initial cutting conditions.