Friction welding of tungsten composite core with AA5754 ballistic cup

Abstract

This paper is a study of mechanical properties and microstructure of rotary friction welded tungsten heavy alloy with aluminum alloy (AA). A plastic deformation is visible on AA side. Effects of friction time (FT) and friction pressure (FP) on the ultimate tensile strength (UTS) were studied by plotting graphs. The UTS of joints increases with increasing FP and FT and then decreases after reaching the maximum value. The fracture proceeds through the cleavage planes at the interface. Scanning electron microscopy for investigation of the fracture morphology and phase transformations taking place during friction welding process was used. Chemical compositions of the interfaces of the welded joints were determined by using energy-dispersive X-ray spectroscopy (EDS). EDS analyses across the interface of tungsten and nickel have not confirmed the diffusion to AA side. Microstructure of friction welds consisted of equiaxed grains formed due to dynamic recrystallization and coarse grains in the periphery region on AA side.