Figure 1 Evolution of round-point clinching technologies
Related Figures (10)
Figure 2. Sequence and characteristics of single-stage shear-clinching (Busse et al., 2010) Figure 3. Experimental setup for the investigations in this paper Figure 3 depicts the characteristics of the chosen tool setup and the properties of the joining partners. Following (Lambiase, 2013), the fixed anvil reduces the material flow in joining direction (die depth 2.0 mm). The opening lamellae (diameter 7.0 mm) enable a lateral extrusion of the punch-sided material and the holding of the die-sided slug. The inner punch has a diameter of 5.6 mm, the characteristic outer punch radius is 6.0 mm with a chamfer (circular ring area perpendicular to aluminium surface) of 0.3 mm. Figure 4. Geometry of specimens and testing method investigated in this paper Figure 5. Geometric characteristics and cross-sections of both material configurations behaviour of the die-sided material. The roll over as a transistion between surface and fracture zone is wider for the HCT780X. This could prevent harm of the punch-sided material. Summarised, the joint formation depends on the die-sided material, from that both configurations are feasible. Figure 6. Online-monitoring of sampling both material configurations Figure 7. Online-monitoring of joining both material configurations/specimen’s geometries Figure 8. Principle of material distribution during the joining process Figure 9. Quasistatic joint strength of investigated conventional specimens Figure 10. Comparison of quasistatic joint strength of investigated specimens Figure 11. Recommended edge distance for single-lap shear load specimen effort and availability of plane sheet metals. Regarding shear strength and specimens rigidity, the authors recommend a minimum edge distance of 9mm when joining AA6016 (2.0 mm) and 22MnB5 (1.5 mm) (Figure 11). To compare different load directions, the same specimen’s geometry has to be used, e.g. LWF-KS2, to avoid deviating joint formation due to different stiffness and edge distances and therefore different energy absorption and damage behaviour. By now, multi-stage clinching with pre-hole on die-side remains state of the art joining technology when joining ductile material and UHSS. But shear-clinching offers great potential as an alternative joining technology for further critical joining tasks. Applications in multi-material design with a desired single-stage joining process and the absence of any additional joining element will benefit from this technology.
