Optimisation of Diffusion Welding Parameters in Al-Cu Bimetal for Shaped Charge Application

Optimum process parameters (temperature, pressure, and time) for diffusion welding of aluminium and copper have been achieved with better shear strength for application in shaped charges using the Taguchi method. The study involved characterising the type and thickness of intermetallic compounds formed at the faying surfaces using optical microscopy, scanning electron microscopy and electron probe micro analyser, lap shear strength assessment, microhardness, and X-ray diffraction. It is confirmed that intermetallic compounds of type Al4Cu (σ), Al2Cu (θ), and AlCu (η1) with traces of Al2Cu3 (δ) and AlCu4 (α2) were formed at the interface. The optimum shear strength of 42.2 N was achieved with diffusion welding at temperature 510oC, pressure 0.5 MPa and time 5400 s. By diffusion welding at these conditions, the shape charge cones fabricated and explosively filled such shaped charges paved, an increase of 0.42 times in the penetration of target with diffusion welded copper-aluminium shape charge cones compared with that from conventional monolithic copper sheet.