Aluminium Matrix Composites

The increasing demand for lightweight material specifications has forced researchers to develop lightweight materials that are inexpensive, can be produced on a large scale, and are environmentally friendly. One solution that has been developed is an aluminum composite reinforced with sea sand. Indonesia has the second longest coastline in the world, which means that the country is rich in maritime resources, one of which is sea sand. The ceramic contents of SiO2, SiC, and Al2O3 allow sea sand to be used as a reinforcement in aluminum composites for engineering purposes. The most effective manufacturing method of AA6061-sea sand composites is stir casting, but the homogeneity and distribution of particles are the main disadvantages of the stir casting method. Various factors affect particle distribution and homogeneity, one of which is the flow during the stirring process. The increase in turbulent flow in the stirring process affects the homogeneity and distribution of the particles. One way to create a turbulent flow when stirring is to add baffles. This paper examines the effect of adding baffles during the stir casting process on the mechanical properties of AA6061-sea sand composites. The mechanical properties of AA6061-sea sand composites were characterized using the Brinell hardness test according to ASTM E-10. The test results show that the addition of baffles during the stir casting process decreases the hardness of the AA6061-sea sand composites due to the turbulent flow that occurs. This makes the material more porous, which makes the AA6061-sea sand composites less hard.

1,2Assistant Professor, Department of Industrial and Production Engineering, Institute of Technology Guru Ghasidas Vishwavidyalaya (A Central University), Bilaspur, Chhattisgarh, India, 495009 3Assistant Professor, Department of Mechanical Engineering, National Institute of Science and Technology, Berhampur, Odisha, India, 761008 4Professor, Department of Industrial and Production Engineering, Institute of Technology Guru Ghasidas Vishwavidyalaya (A Central University), Bilaspur, Chhattisgarh, India, 495009 -----------------------------------------------------------------------***-------------------------------------------------------------------Abstract This review paper is broadly focused on the effect of the different ceramic particulates (SiC, B4C and Al2O3) on the mechanical properties of the Al and Al alloy. Ceramic Particulate Reinforced Aluminium Metal Matrix Composites (PRAMMCs) provide improved properties i.e. improved hardness, improved strength to weight ratio, tensile &...

Hybrid aluminum matrix composites (HAMCs) are the second generation of composites that have potential to substitute single reinforced composites due to improved properties. This paper investigates the feasibility and viability of developing low cost-high performance hybrid composites for automotive and aerospace applications. Further, the fabrication characteristics and mechanical behavior of HAMCs fabricated by stir casting route have also been reviewed. The optical micrographs of the HAMCs indicate that the reinforcing particles are fairly distributed in the matrix alloy and the porosity levels have been found to be acceptable for the casted composites. The density, hardness, tensile behavior and fracture toughness of these composites have been found to be either comparable or superior to the ceramic reinforced composites. It has been observed from the literature that the direct strengthening of composites occurs due to the presence of hard ceramic phase, while the indirect strengthening arises from the thermal mismatch between the matrix alloy and reinforcing phase during solidification. Based on the database for material properties, the application area of HAMCs has been proposed in the present review. It has been concluded that the hybrid composites offer more flexibility and reliability in the design of possible components depending upon the reinforcement's combination and composition.

Hard anodization is an electrochemical procedure used on aluminum and its
alloys to enhance tribo-corrosion performance by creating a thick oxide layer.
Thermal residual stresses, resulting from the difference in the coating and
substrate’s thermal expansion coefficient, promote crack initiation and reduce
the high-cycle fatigue strength (HCF). This work hypothesizes that elastically
prestraining the aluminum substrate can compensate for this mismatch,
minimizing coating irregularities and improving fatigue strength without
developing a new anodizing strategy for fatigue-sensitive anodized components.
Aluminum alloy 6082 is used as the substrate, and a device is built to
apply tensile forces of 800 and 1000 N. Subsequently, the prestrained specimens
are hard-anodized with timeframes of 15 and 30 min, and the coating
thickness, hardness, and morphology are determined. In addition, the HCF of
the coated sample is analyzed and compared with the uncoated sample.
Results reveal that prestraining influences the coating formation and characteristics,
causing early crack initiation and fatigue failure. The observations
show that tensile prestrain exacerbates coating deterioration rather than
mitigating it, showing the complex interaction between the prestrain and
thermal stresses in coating processes. This study demonstrates that prestraining
combined with anodizing degrades the HCF performance of coated
aluminum alloy.

Friction stir processing (FSP) is a novel solid state technique to refine the microstructure of metallic materials. The objective of this work is to apply FSP to change the morphology and distribution of intermetallic particles and achieve property enhancement. AA6061/8wt. % Al 3 Zr composite was produced by the in situ reaction of molten aluminum and inorganic salt K 2 ZrF 6 . Optical and scanning electron micrographs revealed a uniform distribution of needle shape Al 3 Zr particles in the aluminum matrix. The Al 3 Zr particles were located in the inter granular spaces. A double pass FSP was carried out using a tool rotational speed of 1200 rpm, processing speed of 50 mm/min and axial force of 8 kN. A tool made of HCHCr steel; oil hardened to 62 HRC, having a hexagonal profile was used. The needle shape Al 3 Zr particles were fragmented and converted into a spherical shape subsequent to FSP which resulted an increase in the hardness of the composite.

Nanoscaled aluminum nitride (AlN) dispersion strengthened 2024 aluminum alloy was fabricated using a novel approach in which Al-Mg-Cu compacts were partially nitrided in flowing nitrogen gas. The compacts were subsequently consolidated by sintering and hot extrusion. The microstructure and mechanical properties of the material were preliminarily investigated. Transmission electron microscopy and X-ray diffraction results revealed that AlN particles were generated by the nitridation of Al-Mg-Cu compacts. The material exhibited excellent mechanical properties after hot extrusion and heat treatment. The ultimate tensile and yield strengths of the extruded samples containing 8.92vol% AlN with the T6 heat treatment were 675 and 573 MPa, respectively.

Aluminium-based tribological materials may reduce the weight of components, leading to significant fuel economy. The aim of the present study is to investigate the wear and friction in cast in situ Al(Mn)-Al 2 O 3 (MnO 2 ) composites synthesized by dispersing MnO 2 particles in molten aluminium, which get reduced to form Al 2 O 3 particles. Wear tests have been conducted at four normal loads of 9.8, 19.6, 29.4 and 39.2 N and at a constant sliding speed of 1.05 m/s using a pin-on-disc wear testing machine, under dry sliding conditions. The results of the investigation indicate that the cumulative volume loss and wear rate of in situ composites are significantly lower than those observed in either the commercial aluminium or Al-Mn base alloy, under similar loading and sliding conditions. The influences of both reinforcing particle and porosity contents on the tribological behaviour of in situ composites were evaluated. It has been found that at a given particle content, the wear rate increases with increasing porosity content due to its combined effect on real area of contact and subsurface cracking. The wear rate of in situ composites with relatively lower porosity decreases with increasing particle content, but does not appear to change significantly or even increases a little with increasing particle content when the composites have relatively higher porosity. In view of large fluctuations in coefficient of friction during sliding, no effect of particle or porosity contents on the coefficient of friction could be determined unambiguously for different in situ composites.

Development of metal matrix composites has extended the choice of materials particularly for the space, aero-space and automobile industries, with a view to reduce fuel consumption and operating cost by weight saving. Tailoring of a composite to suit a given application requires choice of constituents and promotion of desirable interfaces. Solidification processing of composites demands particular attention to wetting of dispersoids by alloys, defects like porosities and evolution of microstructures particularly in respect of changing the nature of interfaces in a composite.

A hybrid Mg composite filled with micro Al2O3 and nano TiO2 is manufactured through a blend press sinter powder metallurgy route. To appraise the significance of filler incorporation on the mechanical and corrosion strength, the composite is undergoing a series of characterizations. Initially the filler distribution was analyzed through electron microscopes. Static mechanical tests as per ASTM are conducted to measure the influence of fillers on the tensile and compression properties. The corrosion characteristics were studied by immersing the composites into the laboratory synthesized stimulated body fluid (SBF). Through the Tafel Polarization, the corroded surfaces are examined. The corrosion resistance of the composites exhibited a change that closely resembled that of pure magnesium. Based on the experimental findings, it appears that the composite being examined is well-suited for various biomedical applications, particularly in the field of dental implants.

The scope of this book covers the fundamental background of metal matrix composites (MMCs), their processing and fabrication, testing and characterization, exploration of materials for MMCs and green MMCs, and advancements in all aspects of fabrication, testing, and applications. Development or fabrication of MMCs with evaluation of mechanical and tribological properties as well as machinability evaluation, optimization of fabrication process, and machining operations are covered. Features: • Covers advanced processing strategies and machining studies for composite materials • Discusses representative volume element-based FEM modelling approaches and sustainability • Sheds light on advancements in MMC application, fabrication, and testing • Reviews green MMCs and sustainability in MMCs development • Includes case studies and intelligent modelling methodologies This book is aimed at graduate students, researchers, and professionals in micro/nanoscience and technology, mechanical engineering, industrial engineering, metallurgy, and composites.

1,2Assistant Professor, Department of Industrial and Production Engineering, Institute of Technology Guru Ghasidas Vishwavidyalaya (A Central University), Bilaspur, Chhattisgarh, India, 495009 3Assistant Professor, Department of Mechanical Engineering, National Institute of Science and Technology, Berhampur, Odisha, India, 761008 4Professor, Department of Industrial and Production Engineering, Institute of Technology Guru Ghasidas Vishwavidyalaya (A Central University), Bilaspur, Chhattisgarh, India, 495009 -----------------------------------------------------------------------***-------------------------------------------------------------------Abstract This review paper is broadly focused on the effect of the different ceramic particulates (SiC, B4C and Al2O3) on the mechanical properties of the Al and Al alloy. Ceramic Particulate Reinforced Aluminium Metal Matrix Composites (PRAMMCs) provide improved properties i.e. improved hardness, improved strength to weight ratio, tensile &...

Aluminium composites have found their strength in engineering applications such as automotive, electrical and light-weight applications. To achieve uniform microstructure and good mechanical properties, the fabrication techniques are prime factors in controlling wettability and porosity problems. This research therefore aimed for studying microstructuremechanical property relation of SiC p -reinforced 356 aluminium composites fabricated by a costeffective stir casting process, to which three elemental additions, Al-5Ti-B, Sr, and Mg, were investigated. Furthermore, effects of SiC p additions (0-15 wt.%) and T6 heat treatment (530 º C/12h + 155 º C/4 h) on mechanical properties of the composites were also studied. The 356 aluminium ingot was melted at 700 º C then stir-mixed with pre-heated SiC p of 10.5 μm average size at 500 rpm, 615 º C prior to casting into cylindrical permanent molds at 650 º C. Microstructure examination along with hardness and tensile tests were carried out. The results showed that, with Mg and Al-5Ti-B and Sr additions, the optimum SiC p addition was observed to be at 10 wt.% to achieve microstructure homogeneity beneficial for hardness and tensile properties.

Extended Abstract An economic way to reduce shocks and mechanical vibrations in engineering applications is to use high damping materials. For practical applications damping materials must exhibit, simultaneously, good mechanical properties at room and high temperature, and high damping capacity. This requirement is fulfilled when the microscopic mechanisms responsible for the dissipation of the vibration energy (internal friction) are independent of the hardening mechanisms. For most materials these are contradictory requirements. One way to achieve a compromise is to design multiphase composites in which specific phases are assigned specific damping or mechanical strength roles [1] . Metal-ceramic composites are typical examples. The purpose of this research is to explore the use of shape memory alloy as the metal phase in the interpenetrated phase metal-ceramic composite designed for vibration damping applications.

The mechanical behaviour of an aluminium metal matrix composite foam structure under quasi-static uniaxial compressive loading (compressive strength, energy absorption behaviour, stress-strain characteristic behaviour) has been studied in this work. The aluminium alloy Al 7075 is used in the foam structure, and it is reinforced with weight SiC (1%, 2%, 3%, 4%, 5%), B4C (5%, 4%, 3%, 2%, 1%) particles. Using a high-resolution optical zoom microscope image, the microstructural surface morphology of the manufactured metallic foam samples was also examined for the aforementioned composition. The analysis included pore size, porosity percentage, and distribution, as well as cell wall thickness. For all characterisation investigations, wire EDM was used to cut samples with dimensions of 3 cm x 2 cm x 2 cm from the As-cast ingot, which had a diameter of 5 cm and a length of 10 cm.

In this research work 3 wt. % and 5 wt. % of tungsten oxide (WO3) particulates are reinforced the Al-5Mg-5Zn alloy. Two-step liquid stir casting processing route is used for the development of these particulate reinforced aluminium alloy metal matrix composites. The mechanical and the tribological properties such as Brinell hardness, impact toughness and dry sliding wear resistance of the as-cast Al-5Mg-5Zn alloy matrix and the prepared Al-5Mg-5Zn/WO3 particulate metal matrix composites are analysed according to ASTM standards. The worn-out surfaces of the test samples during the wear test of the developed compositions are also analysed by using optical microscopy to express the patterns of wear. The results show that the addition of WO3 particulates improved the hardness as well as dry sliding wear resistance of the Al-5Mg-5Zn alloy and these properties are also increased with the increase in the wt. % of WO3. The value of impact toughness decreases with the addition of WO3 particulates as well as increasing the wt. % of WO3 particulates.

The present era is the modern era in which Al Metal Matrix Composite (MMC) plays an important role as compared to conventional materials. In this research work 5 wt. % Zn present in Al-5Mg-5Zn + 3 wt. % WO3 particulate reinforced Al Metal Matrix Composite is replaced with 5 wt. % SiC particulates and fabricated the Al-5Mg + 3 wt. % WO3 + 5 wt. % SiC hybrid MMC. To fabricate these particulate reinforced Al MMC, two step stir casting method is used. The stir casting route is simplest and most cost effectiveness method for liquid state processing. Hardness, impact toughness and dry sliding wear of the developed MMCs are investigated by following ASTM standards of the tests. The results show that by using SiC particulate instead of Zn improved the hardness value of the MMC but decrease the values of impact toughness, weight loss, sliding wear rate and volumetric wear rate. This advance material have many application i.e. satellite & helicopter structures, static and rotating components of engine and compressor blade due to its wear resistance with lightweight properties.

In this modern era, aluminium metal matrix composites (AMMCs) are replacing all the conventional materials in rapid way due to its outstanding characteristics and play very important role in various industries i.e., automobile & sports. In this research work 5 weight percent of Boron Carbide (B4C) particulates are used to reinforce the AA5052 matrix by easiest and cost-effective stir casting route of liquid processing technique to develop metal matrix composites (MMC). The variation of volume loss, volumetric wear rate, volumetric wear resistance, frictional force, wear depth, and relative wear depth of the developed AMMC and unreinforced AA5052 are investigated at different applied load and compared these properties between them. To analyze these properties, pin-on-disc abrasive wear test were carried out according to ASTM G132 for the applied load range of 5-15N and the density was measured by using Archimedes’ principle. Vickers hardness of the developed compositions is also analysed as per ASTM E92. The results show that at all applied load, AA5052/B4C AMMC having improved wear resistance and reduction in wear rate with lower density & higher hardness as compared to the AA5052 matrix.

This review article summaries the characterization of sliding wear behavior of different ceramic particulate reinforced Aluminium Metal Matrix Composites (AMMC) investigated by various researchers in last few decades. The effect of various parameters i.e. sliding distance, applied load, testing time, testing media, rotational speed, weight fraction of reinforcements, particle size of reinforcements etc. are considered for characterization of various tribological properties i.e. frictional force, coefficient of friction (COF), wear rate etc. of the particulate reinforced AMMCs. For the characterization of these tribological properties, the tests were carried out on the pin-on-disc tribometer as per ASTM G99. AMMCs are demanded materials for this modern age, because they work as functionally graded materials for various industries like automobile, sports, aircraft, marine etc.

This review paper is broadly focused on the effect of the different ceramic particulates (SiC, B4C and Al2O3) on the mechanical properties of the Al and Al alloy. Ceramic Particulate Reinforced Aluminium Metal Matrix Composites (PRAMMCs) provide improved properties i.e. improved hardness, improved strength to weight ratio, tensile & compressive strength, creep & fatigue resistance etc. as compared to conventional Al and Al alloy. Aluminium Metal Matrix Composites (AMMCs) are preferred to use in aerospace, automobile, sports, marine application etc due to its lightweight and high strength property. This manuscript reported the pioneering work of most of the researchers in the field of mechanical characterizations of ceramic PRAMMCs. The effects of weight or volume percentages and particles size of the reinforcement on the properties of AMMCs are discussed in this article.

This article deals with a summary of different fabrication methods of Aluminium Metal Matrix Composite (AMMC). This modern age demands the lightweight materials with very high strength, wear resistance, and corrosion resistance property for various industries i.e. aerospace, automobile, sports, etc. These requirements can't be fulfilled by the monolithic alloy or conventional materials. Metal Matrix Composite (MMC) overcomes these limitations of the monolithic alloys because MMCs have desired properties like high strength to weight ratio, good mechanical as well as good tribological properties and due to its advantageous properties MMCs are used for automobile & aircraft. The use of MMCs reduces the power requirement and also gives low emission and low noise. This article focused on the various techniques developed for the fabrication of AMMCs by the no. of researchers in the last few decades. These methods are either liquid state processing or solid-state processing. In the case of weight-saving requirements, researchers used AMMCs due to its lightweight property.

The In-situ composite of metal matrix AA6063-xTiC (x = 0 wt. %, 3wt. %, 6 wt. %, 9 wt. %) were mixed with particulates of Tic, were synthesized by the reaction of K 2 TiF 6 and graphite with aluminum melt at 1000°C. These composites were heat treated differently to form various sets like solution zed and solution zed-aged, where they were compared with as-cast composites for erosive wear performance by testing pot type slurry-erosive wear device, respectively. This study showed an increase in wear resistance for slurry erosion upon solution zed-aged heat treatment and with a rise of Tic particulates.

The wear of component is regularly a serious issue prompting the product provision period. Wear prophecy is consequently a vital area in technology. The wear recreation method with profitable software ANSYS 10.0 finite element (FE) was implemented with the linear wear Archard equation. The wear of commercially available brake pad sliding against Ti-6Al-4V disc was analyzed with FEM under different operating conditions such as normal load, sliding velocity, sliding distance and operating temperature. A 3D-8 node structural element (SOLID 185) and 3D-8 node surface-to-surface contact elements (Target 170 and Contact 174) is used to analyze the wear of pin and disc. Using ideal boundary conditions, the simulation predicts the wear rate, wear depth, contact pressure and contact friction stresses under different operating conditions at the contact zone.

This paper summarizes the experimental investigations for augmented dry sliding property of AA 6063/TiC composite. An in situ metal matrix composite has been prepared with AA 6063 alloy for the matrix and TiC for reinforcement particulates. The fabrication of the composites is done by using potassium titanium fluoride (K 2 TiF 6) and powder of graphite as a mixture for reaction along with molten aluminum alloy at 950 °C. The weight fraction of TiC particulates has been varied in the composites C 0 , C 1 , C 2 , and C 3 as 0, 3, 6, and 9%, respectively. Various characterization techniques and tests were conducted to observe the morphological properties of the composites. The composites were categorized into three sets. The first set of the composites is as-cast condition. The composites were heat-treated to form two more sets, namely solutionized and solutionized-aged condition sets. The "pin-on-disk" apparatus is used for conducting the tests, wear analysis, and comparative analysis of the wear for the dry sliding condition. The study indicated a significant enhancement of the resistance to wear by composites with the higher fractions of titanium carbide (TiC) particulates and further enhancement with the heat treatment.

When choosing a material for automobile piston components, be sure to choose one that satisfies all necessary specifications, like durability, resistance to temperature, and wear resistance. To achieve maximum efficiency and effectiveness, factors including cost, weight, and production procedures are also taken into account. Aluminium alloys that are forged iron, and steel are common material for piston components; each has certain benefits and compromises in terms of expense and efficiency. Introduction: Material selection for auto piston components is critical to ensuring top performance and long-term durability. The piston, as a vital engine component subjected to high temperatures, hardship, and wear and tear, necessitates a material that promotes efficient combustion, lowers friction, and maintains its structural integrity. When selecting materials for automobile pistons such as aluminium alloys, wrought iron, or steel, aspects such as heat conductivity, resistance to wear, size, expense, and manufacturing capability are carefully considered to satisfy the specific needs of the application. Research Significance: Aluminum, steel, along with iron are the better frequently used goods for pistons. The effort from the expanding gas at great heat matters about the inside. Cylinder and many other important factors determine proper piston selection Material necessity are balanced more demanding, just as no single material meets all the properties required for a distinct application. Method: The weighted sum method is a decision-making approach that involves assigning weights to different criteria or objectives and combining them to make an overall assessment. It allows decision-makers to prioritize and balance various factors based on their relative importance. By utilizing this method, complex decision problems can be simplified and converted into a single weighted score, facilitating a clearer understanding of trade-offs and aiding in the decision-making process.

This paper presents basic tribological properties of A356/10SiC/1Gr hybrid composites in conditions with lubrication. Hybrid composite specimen is obtained by compocasting procedure. A356 aluminium alloy is used as a base matrix alloy, reinforced with 10wt% of SiC and 1wt% of graphite. Tribological tests are done on advanced and computer supported tribometer with block-ondisc contact pair. By the experimental plan, test is conducted under three different values of sliding speed, three different values of normal load, different sliding distances, and also different lubricants. SEM and EDS are used for wear analysis. The analysis has shown the presence of MML, which means that there was transfer of material from steel disc to composite block.

In the present study, a mathematical model is proposed for the prediction of wear rate of Al-12.6Si alloy-based composites reinforced with in situ TiB2 (2, 3, 5 wt%) particles by halide salt reaction route. For deducing an empirical relationship for wear rate (pin-on-disc type wear), a multiple regression analysis has been performed to show its dependency on the TiB2 content of composite and various wear test parameters. From the regression statistics, it is inferred that the wear rate is strongly dependent on the rotating speed of the disc but moderately on the TiB2 content and applied normal load.

Przedstawiono wyniki badań właściwości tribologicznych (współczynnik tarcia, zużycie) par ciernych żeliwo-kompozyt. Badaniom poddano kompozyty homofazowe i heterofazowe zbrojone cząstkami SiC lub Al2O3 z dodatkiem węgla szklistego (tab. 1). Badania przeprowadzono, wykorzystując tester tribologiczny T-01, a partnerem tarcia dla kompozytów było żeliwo (rys. 1). Zastosowanie zbrojenia heterofazowego jest rozwiązaniem pozwalającym w znacznym stopniu rozszerzyć możli-wości projektowania właściwości tribologicznych skojarzeń ciernych. Możliwe staje się bowiem dobieranie takich układów zbrojenia, dzięki którym przy zachowaniu wysokiej wartości, a także stabilizacji współczynnika tarcia (rys. rys. 3 i 4) można ograniczyć zużycie elementów pary ciernej (tab. 2), ma to miejsce w przypadku kompozytów zbrojonych cząstkami jednakowej wielkości z dodatkiem węgla szklistego A50Cs i S50Cs. Jest też możliwe zmniejszanie wartości współczynnika tarcia w zależności od potrzeb konstrukcyjnych. Efekt ten można osiągnąć poprzez zastosowanie do zbrojenia kompozytów mieszaniny cząstek o różnej średnicy (materiały zbrojone: Al2O3 25, 50, 100 μm, SiC 25, 50, 100 μm) lub przez zastosowanie cząstek różnej średnicy i dodatkowo węgla szklistego (materiały zbrojone: Al2O3 25, 50, 100 μm + Cs 100 μm, SiC 25, 50, 100 μm + Cs 100 μm). Przedstawione w artykule wyniki badań dowodzą, że dodatek węgla szklistego bez względu na rodzaj ceramicznego zbrojenia poprawia właściwości tribologiczne układu. Wpływa on na stabilizację wartości współczynnika tarcia w funkcji drogi tarcia i znacznie obniża zużycie współpracujących elementów. Słowa kluczowe: stop aluminium, cząstki ceramiczne, węgiel szklisty, właściwości tribologiczne Aluminium-based metal matrix composites are well-known for their high specific strength, stiffness and hardness. They are gaining further importance as their potential for wear resistance becomes established. In general, for sliding against metal and abrasives, many studies have reported that composites exhibit better wear resistance than the unreinforced alloys. The subject of the article are heterophase composites (ceramic particles, class carbon type) and production and evaluation of their tribological properties. The reduction of the results of the hard reinforcement particles influence on the collaborative element is possible thanks to the application of heterophase reinforcement (composed of several kind of reinforcement particles) (Tab. 1). The solution presented in the article assumes the wear reduction in the dry sliding conditions through the appli-cation of the Al2O3 and glass carbon mixture and SiC and glass carbon mixture as the reinforcement. For all samples sliding distance was 5000 m, load 35N and sliding velocity 0.5 m/s. Abrasion was carried out with the use of tribological tester T-01 pin-on-disc (Fig. ). Composite materials for the investigation composed of AK12+30% (Al2O3) were produced with the use of the suspension method. Generated material was formed in the shape of sleeve with the application of centrifugal casting. It permitted to produce composite layer which structure was composed of glass carbon particles surrounded by smaller diameter Al2O3 or SiC particles (Fig. ). The investigation of the frictional composite-cast iron couple association conducted in the dry sliding conditions proved that addition of 5% glass carbon reduces 30% of cast iron wear and 20% of the friction coefficient (Figs and). Microscopic examination of the erosion trace showed that heterophase reinforcement reduces composite abrasive wear (Tab. 2). Conducted researches gave expected results and further investigation will focus on the optimization of the phase composition proportion.

To segregate the Titanium (Ti) from the reinforcements of the molten scrap of Titanium/Aluminum (Ti/Al) composite, application of ultrasonic vibration is known to be one of the sound techniques. Various studies have been looked at the effect of ultrasonic vibration on the melting process, however not much have been investigated with respect to the solidification process. To fabricate Ti/Al composites in situ, ultrasonic vibration can be effectively used to compress the solidifying melt during the casting process. In this line, the present study focused to investigate the influence of ultrasonic vibration and squeeze pressure on solidification behavior of the α-Al matrix, characteristics of the matrix-reinforcements interface, and distribution of reinforcements. The experimental data indicated that when the amplitude was 60 μm, the Vickers hardness, yield strength, and tensile strength of composites increased by 8.6, 3.9, and 3.1 %, respectively, due to gravity casting. While the squeeze pressure was increased from 50 to 100 MPa, the mean grain size decreased from 90 to 60 μm during the ultrasonic aided squeeze casting (SC) process. However, as the squeeze pressure was raised, the microstructures became coarser and the mechanical characteristics weakened. Yield strength, and tensile strength were increased by 18.7% and 3.2%, respectively, when the squeeze pressure was 100 MPa.

The present investigation is aimed at studying the effect of dispersoid content and effect of chill on microstructure and mechanical properties of aluminum alloy (LM 13) hybrid metal matrix composites reinforced with garnet and fixed 3wt.% carbon. The size of the garnet particles varies from 50 to 80 μm and amount of addition varies from 3 to 12 wt.% in steps of 3 wt%. By using chills of different material with different volumetric heat capacity (VHC), the effect on the microstructure evolution was examined. Stir casting process was used to produce chill cast aluminum alloy-garnetcarbon particulate composites in moulds containing various chills of copper, steel, iron and silicon carbide to accelerate the solidification. The fabricated composites were tested for their hardness and ultimate tensile strength properties according to ASTM standards. The effect of chill and reinforcement characteristics was presented and compared with the hybrid composite without chill material. Microstru...

In this study, an attempt was made to correlate the propagation of ultrasonic waves to various microstructural features in Al -SiC composites. The investigated parameters include the volume fraction, size, and distribution of the SiC-reinforcing particulate. Composites were fabricated by hot pressing of Al, Cu, and SiC powders. It has been shown that the ultrasonic velocity in all composites increased with an increase in SiC content. At identical volume fraction, changing the size of SiC particles did not affect the velocity. However, a segregation of SiC particles along the grain boundaries caused a decrease in ultrasonic velocity, which was attributed to the higher amount of residual porosity in segregated structures.

Microstructure evolution over a wide range of growth rates has been examined in the Al-Sm system in which different microstructure selection, from eutectic to dendritic to amorphous material, with increasing growth rate can occur. Experiments were carried out for compositions between 11 and 25 wt.% Sm and the velocity was varied from 2x10 -4 to 635 mm/s. Low velocity studies were carried out using the Bridgman technique, whereas high velocity studies were carried by using the laser scanning technique. The maximum velocity for eutectic growth was determined, and the results were compared with the theoretical predictions. A transition from eutectic to α-Al dendrites was observed when the eutectic became unstable, and a coupled zone boundary on the Al side was determined. The present results were compared with those in the Al-Cu alloys, and the velocity at which the eutectic becomes unstable was found to be an order of magnitude smaller, which is related to the higher activation energy for diffusion in the Al-Sm system.

This paper presents tribological characteristics of hybrid composites with aluminium matrix, reinforced with silicon carbide (Sic) and graphite (Gr). Newly formed Al/Sic/Gr hybrid composites are the combination of the two different hybrid materials. Namely, hard particles of silicon carbide increase the hardness and resistance to wear, while soft particles of graphite improve lubrication and reduce friction coefficient and wear. It is possible to obtain Al/SiC/Gr hybrid composites by different methods of casting. Tribological tests show that load, sliding speed, sliding distance, content and size of reinforcement particles influence the size and the type of wear and friction coefficient of Al/SiC/Gr hybrid composites with aluminium matrix.

This paper presents basic tribological properties of A356/10SiC/1Gr hybrid composites in conditions with lubrication. Hybrid composite specimen is obtained by compocasting procedure. A356 aluminium alloy is used as a base matrix alloy, reinforced with 10wt% of SiC and 1wt% of graphite. Tribological tests are done on advanced and computer supported tribometer with block-ondisc contact pair. By the experimental plan, test is conducted under three different values of sliding speed, three different values of normal load, different sliding distances, and also different lubricants. SEM and EDS are used for wear analysis. The analysis has shown the presence of MML, which means that there was transfer of material from steel disc to composite block.

IN-SITU Al 2 O 3 SiC C having 20 wt%, 25 wt%, 30 wt% and 35wt% of powdered particulate were fabricated by liquid metallurgy (stir cast) method. The composite specimens were machined as per test standards. The specimens were tested to know the common casting defects using image analyzer. Some of the mechanical properties have been evaluated and compared with Al6061 alloy. Significant improvement in uniform distribution of particulates is noticeable as the wt % of the flake particles increases. The microstructures of the composites were studied to know the dispersion of the powdered particles in the matrix. It has been observed that addition of flake particles significantly improves particulate distribution.

Tribology experiments have a crucial importance in order to verify results of simulations and calculations and sometimes it is the only way to solve important problems and tasks. Numerous requirements in experimental investigations now days need a new approach in data acquisition (DAQ) tools and methods, where time and mobility are taking significant place. Last years LabVIEW software made a great expansion in industrial measurement applying and virtual instrumentation in data acquisition. The aim of this paper is to present some advantages of standard and portable DAQ Equipment with LabVIEW software and to show their application in some common tribology experiments. This equipment is also excellent tool in condition monitoring of mechanical systems from the aspect of tribological parameters. By comparing classical experimental techniques and simulations with Lab VIEW possibilities in combination with portable hardware modules, this paper will serve as a support for the development of new approach in tribology experimental investigations and their involving in general concept of condition monitoring. It is obvious, that the ambitious aims of this concept has a multidisciplinary approach by integrating this advance research and education tool of experimental design in mechanics, fluid dynamics, micromechanics etc.

Base metals are often reinforced with fibres to improve their mechanical behaviour; however, it is imperative to decide the range of fibres orientation that would yield favourable strength. In this work, using sand casting method, aluminium is reinforced with galvanized steel fibres at different orientations with the aim of investigating the anisotropic mechanical behaviour of the composites. The fibre orientations considered are 0°, 30°, 60° and 90°; while the mechanical properties evaluated are impact energy, tensile, compressive and fatigue properties. Unreinforced aluminium exhibits impact energy, elongation-at-fracture, ultimate tensile strength, and maximum compressive

Subject review Strict requirements that are put on mechanical constructions from the aspect of increase of exploitation periods and reduction of their weights, therefore of their prices as well, implicate developments and applications of new composite materials with matrices of lightweight metals. Composite materials with metal matrices are used for engine cylinders, pistons, disc and drum brakes, Cardan shafts and for other elements in automotive and aviation industry. The most important type of metallic materials is composite materials with matrices of aluminium alloys due to a set of their beneficial properties. Improvement of mechanical, especially tribological properties of hybrid composites were provided by the use of certain reinforce materials such as SiC, Al2O3 and graphite in defined weight or volumetric share. New developed hybrid composites with aluminium matrices have significantly higher resistance to wear, higher specific stiffness and higher resistance to fatigue. By the increase of quantities of produced elements made of hybrid composites, decrease of their prices is induced that even further enlarge their applications. The applications of aluminium hybrid composites are considered from the aspect and with the focus on automotive industry.

Al-12Si-3Cu-1 Mg-1.78Ni alloy is widely used for piston parts in automobile industry. The present paper investigates the effect of aging time for 1-16 h at 180°C after solution treatment of the alloy at 500°C for 5 h, on alloys prepared by gravity casting and squeeze casting. The wear rate of the alloy shows a minimum at an intermediate aging time. The hardness and ultimate tensile strength showed a peak at intermediate aging time. Mechanical properties and wear resistance are found to be better in squeeze cast alloy. The result are explained based on the microstructure developed during casting process and on heat treatment for various durations.

Particulate reinforced aluminum matrix composites are attractive materials due to their strength, ductility, toughness. This study presents the result of an experimental investigation on the mechanical and wear properties of aluminum alloys 6061 MMC reinforced with glass particulate of 40 microns where dispersed in aluminum matrices at 2, 4, 6 and 8 wt%. Therefore judicious selection of the variables is important to optimize the properties of composites. The shape, size, volume fraction and orientation of reinforcement particles and matrix compositions have to be carefully chosen. The composite prepared by stir casting method the stir casted specimen wear tested for the mechanical and wear properties. The aluminum matrix is strengthening when it is reinforced with hard ceramic phases. In this work the effect of Glass particulate in aluminum matrix on the mechanical and wear properties of the composites is investigated the mechanical properties of composite materials are strongly dependent on micro structural parameters of the system the investigation relives that the significant improvement in the mechanical and wear properties of the composites.

Aluminium matrix composite memiliki sifat mekanis yang baik dibandingkan dengan paduan aluminium tanpa penguat. Jenis aluminium yang digunakan A356 yang banyak dipergunakan pada bidang teknik. Penelitian ini bertujuan untuk mengetahui pengaruh sudut kemiringan yang dilakukan pada saat pengecoran logam terhadap sifat mekanis kekerasan, impak, tarik, keausan dan mikrostruktur. Spesimen dibuat menggunakan pengecoran metode cooling slope dengan diberi variasi sudut kemiringan 15o, 30o, 45o, 60o, dan 75o dengan temperatur tuang 680oC serta campuran SiC 0,5%wt dan 2,5%wt. Kekerasan rata-rata tertinggi diperoleh pada campuran 2,5%wt SiC sudut kemiringan 30o adalah 55,74 BHN. Energi impak tertinggi didapat pada campuran 0,5%wt dengan sudut kemiringan 75o yaitu sebesar 12,87 Joule dan nilai tertinggi sebesar 0,156 Joule/mm. Pengujian keausan dilakukan dengan metode pin on disk dengan variasi putaran 150 Rpm, 180 Rpm, 210 Rpm. Nilai rata-rata tegangan tarik material Al-SiC tertinggi didapat p...

In the article, the authors present results of microstructural studies of Al-Mg-Si-Mn casting alloys with Zr, Li, and TiB 2 additions on a broad scale. Zirconium content was set on two levels: 0.34 and 1.58 wt%, and Li was set 1.2 and 2.0 wt%. It was found that the addition of Zr shifts the eutectic melting temperature to a higher level, up to 611.3°C at 1.6 wt% Zr. At the same time, Li addition leads to the depression of eutectic melting temperature: down to 587.2°C at 2.0 wt% Li, what is a common effect of eutectic modification which was confirmed by means of structural examinations. The complex addition of Li and AlTi5B1 resulted in a eutectic melting temperature close to the equilibrium eutectic temperature for the Al-Mg-Si system (596.2°C). The grain refinement effect of Zr is due to the nucleation of a-Al on the Zr(Al 1-x , Si x) 3 phase. Crystals of this phase were detected in the grain centers of Zr-containing alloys. The Li addition does not affect a-Al grain size but changes the morphology of eutectic colonies from petal-like to fibrous. Observation of TiB 2 particles inside the primary Mg 2 Si crystals gives direct experimental confirmation of nucleation of the primary phase on the surface of TiB 2 in the alloy after adding Li and AlTi5B1. Natural aging of the alloys resulted in the formation of fine precipitates detected close to dislocations. The most apparent supposition is that the mechanism responsible for their formation is heterogeneous nucleation in the stress field of dislocations. Hardness tests showed adding 2.0 wt% of Li is very effective, increasing hardness up to 113 HV0.2 in naturally aged condition, which is nearly double that of commercial Al-Mg-Si die-casting alloy. Several effects were proposed which may synergistically contribute to the rise of hardness in Li-containing alloys, such as solid solution strengthening, formation of primary LiAlSi phase and natural aging.

Prosthetic limbs serve as indispensable tools in restoring mobility and enhancing the quality of life for individuals with limb loss. This project focuses on the modeling and analysis of prosthetic legs, aiming to optimize their design for improved functionality and comfort. The study begins with an exploration of the significance of prostheses in enhancing the mobility and independence of amputees. Utilizing Solid Works for modeling and ANSYS for analysis, the project investigates the performance of prosthetic legs constructed from four distinct materials: Aluminum Alloy, Titanium Alloy, Carbon Fibre, and Structural Steel. These materials are selected based on their mechanical properties and suitability for prosthetic applications. The design and analysis stages involve simulating various activities that mimic the typical movements and stresses encountered during daily l ife, including walking and engaging in other essential tasks. By subjecting the prosthetic leg models to rigorous testing, the project evaluates their durability, strength, and overall performance under realistic conditions. The outcomes of this research provide valuable insights into the comparative advantages and limitations of different materials in prosthetic leg design. Additional ly, it offers recommendations for optimizing prosthetic limb design to better meet the diverse needs and preferences of users. Ultimately, this work contributes to advancing the field of prosthetic engineering, paving the way for the development of mor e efficient and user-friendly prosthetic solutions.

This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

This work analyzes fatigue resistance of aluminum matrix composites with the support of robust statistics. The experimental samples studied were aluminum-based composites with a matrix containing Al, Cu and Mg and reinforced with diboride particles fabricated via both gravity and centrifugal casting. The variation in fatigue strength due to boron addition (forming diboride particles) was assessed via a comparison of the Paris equation exponent calculated for each composition as the slope of the da/dN vs ΔK curve plotted on a log-log scale. This approach, combined with the implementation of Kujawsky's crack driving force parameter and the application of robust statistics, allowed identifying variations in the crack growth behavior due to heterogeneities in the microstructure. The results showed that samples obtained via centrifugal casting have a higher fatigue resistance than those obtained via gravity casting. In addition, the analysis demonstrated how crack growth resistance decreased by increasing amounts of reinforcing particles in the material. The use of a robust statistics analysis was fundamental to avoid rejecting data from samples exhibiting variations in the crack growth curve. Keywords-Fatigue crack growth; robust statistics; aluminum matrix composites.

This research paper deals with AA 6061 composite material with various amounts of weight percentage (wt%) of reinforcements of aluminium nitride (AlN) and zirconium boride (ZrB 2). The various amounts of reinforcements like 0 wt%, 3 wt%, 6 wt%, 9 wt% and 12 wt% were mixed with matrix by in situ method of stir casting. Then, the mechanical properties like hardness, tensile and compressive strengths were analyzed as per ASTM standards. The microstructure shows the particle distribution and dispersion within the composites and X-ray diffraction (XRD), energy dispersive spectrograph (EDS) analyzed the constituents of AA 6061 composites. The wear resistance is examined by pin on disc method with various input parameters like composites (wt%), Load (N) and Velocity (m/s). The wear rate (mm 3 /m) was calculated for each wt% of reinforcements by mass loss (g). The SEM examination was conducted before and after the wearing of AA composites to study the consequent worn surfaces and defects. The optimization techniques like Taguchi and ANOVA were then applied to obtain the best processing parameter and most significant parameter of the AA 6061 composites. The theoretical and optimization results were compared for identifying the best results with GA.

This research paper deals with AA 6061 composite material with various amounts of weight percentage (wt%) of reinforcements of aluminium nitride (AlN) and zirconium boride (ZrB 2). The various amounts of reinforcements like 0 wt%, 3 wt%, 6 wt%, 9 wt% and 12 wt% were mixed with matrix by in situ method of stir casting. Then, the mechanical properties like hardness, tensile and compressive strengths were analyzed as per ASTM standards. The microstructure shows the particle distribution and dispersion within the composites and X-ray diffraction (XRD), energy dispersive spectrograph (EDS) analyzed the constituents of AA 6061 composites. The wear resistance is examined by pin on disc method with various input parameters like composites (wt%), Load (N) and Velocity (m/s). The wear rate (mm 3 /m) was calculated for each wt% of reinforcements by mass loss (g). The SEM examination was conducted before and after the wearing of AA composites to study the consequent worn surfaces and defects. The optimization techniques like Taguchi and ANOVA were then applied to obtain the best processing parameter and most significant parameter of the AA 6061 composites. The theoretical and optimization results were compared for identifying the best results with GA.

Over the years, Al-7Si-Mg alloys are used because of their excellent castability, high weight-to-strength ratio, good corrosion resistance and good weldability. In this paper, the fatigue behaviour of Al-7Si-0.3Mg alloys, conforming to A356, has been studied. Specimens of this material were fatigue tested in both the as cast condition, solution treated and aged conditions. The fatigue test was conducted using 3-point fatigue bending setup with the principle of low cycle fatigue failure mechanism. Overaging is found to affect the fatigue behaviour of Al-7Si-0.3Mg alloys. The fatigue properties of as cast alloys showed a three times increase upon solution treatment. Peak ageing condition further improves the fatigue value. Exposure to severe overageing conditions reduced the fatigue properties somewhat from that of the peak values but still maintained higher value than the as-cast conditions, which is constant irrespective of the overageing condition. The improved fatigue properties of heat treated samples can be generally attributed to the spheroidisation of acicular silicon particles.