Mechanical and Microstructural Characterization of Percussive Arc Welded Hyper-Pins for Titanium to Composite Metal Joining

The manufacture of Ti- composite hyper-joints for aerospace applications requires arrays of pins to be attached to a metal component's surface. Here, the feasibility of using percussive arc micro-welding for this purpose has been explored, applied to dissimilar Ti alloys, to allow advantage to be taken of tailored pin properties. To simulate the process, Timetal21s wire pins were welded to a Ti-6Al-4V baseplate under optimized parameters. Analysis of the welds indicated the presence of martensitic microstructures and chemical inhomogeneity in the melt pool, as a result of the rapid weld cycle (5 ms). The performance of the welded pins was assessed by a micro-tensile and a pin shear/bend test, assisted by FE modeling.