Spot Joining of PVC to Aluminum Sheets via Cold Forward Extrusion

An essential consideration for metal-polymer applications is that the sound joining of these materials is challenging due to a significant surface energy differential in different structural characteristics between polymer and metal. However, the joining methods have some drawbacks, such as low-reliability joints, long curing time, stress concentration, and polymer degradation. A new novel metal-polymer hybrid joining technique is proposed in this work to overcome these issues and cost perspectives, manufacturing, and overcoming the problem of PVC degradation due to heat generation of other joining methods. In this study, we managed to join PVC to AA5053 sheets using a cold joining technique based on extruding PVC through a conical hole of an aluminum specimen using a punching tool. Experiments consisted of three parameters (the hole diameter, plunging depth, and radius of the punch), with four levels for each parameter. The experiments were designed, and mechanical characterizations of the joints were optimized using the design of the experiment's method. The hole diameter was the effective parameter on the mechanical characterizations and dimensions of the extruded PVC. Increasing the diameter of the AA5053 sheet increased the maximum diameter of the extruded PVC, shear force, and pull-out force of the joints and decreased the shear stress of the joints. We obtained a maximum shear strength of 106.15 MPa, which is ~3 times higher than the tensile strength of PVC (37 MPa).