Improving Porous TC4/UHMWPE Friction Spot Welding Joint Through Controlling Welding Temperature and Force

Joining between metal and polymer has attracted significant attention recently due to its advantage of great weight reduction and excellent integrated physical/chemical properties. In this study, specially designed biomedical additive manufactured porous TC4 titanium alloy plate was successfully joined to ultra-high molecular weight polyethylene (UHMWPE) plate by friction spot welding (FSpW). The z-axial load (Fz) evolution has been measured with load cell, and welding temperature (Tw) near TC4/UHMWPE interface has been measured with thermocouple. High tensile shear strength (~3000 N) has been realized through strong mechanical interlocking. Good macro-penetration of UHMWPE into TC4 porous structure (up to 80% filling rate) and sound micro-interlocking between metal and polymer were obtained. Relationship between Tw/Fz and joint quality has been unveiled for the fabrication of defect-less joints.