Collision Welding of Tungsten Alloy 17D and Copper Using Vaporizing Foil Actuator Welding

Abstract

The objective of this study was to implement collision welding of tungsten alloy 17D (6.5% Ni, 3.3% Fe) and copper at a laboratory scale and subsequently investigate the relationship between interfacial structure and mechanical properties. Vaporizing Foil Actuator (VFA) has recently been demonstrated as a versatile tool for metalworking applications, such as impact welding of dissimilar materials. Its implementation for welding is termed as VFA welding or VFAW. With 8 kJ input energy into an aluminum foil actuator, a 0.5 mm thick Cu110 alloy sheet was launched toward a tungsten alloy target resulting in a collision at a velocity of 580 m/s. The two sheets were found to be welded in the region where the collision velocity and angle were optimal. This range, termed as the welding window was found to be narrow for this combination of target and flyer materials. Scanning electron microscopy of sectioned samples showed regions of wavy interface with significant plastic deformation on both sides. Microhardness tests revealed significant increase in hardness near the interface. Instrumented peel tests showed that the welds were quite strong with peel strength of 60 N/mm.