Microstructure and mechanical properties of the bonded interface of laser impact welding brass/SS304

In this study, laser impact welding experiments on H62 brass and stainless steel 304 (SS304) were carried out, the feasibility of welding the two alloys was analyzed, and the influences of laser energy and flyer plate thickness on the surface morphology and interface waveform of the welded joint were studied. The elemental distribution of the welding interface was measured and examined. The mechanical properties of the welded sample were also systematically explored. Results show that weldability between the flyer and the substrate plate at a flight distance of 0.2 mm is the best when the other process parameters are the same. When the thickness of the flyer plate is constant, the amplitude and wavelength of the bonding waveform decrease as laser energy decreases. Under the same laser energy, the amplitude and wavelength of the interface waveform decrease as flyer plate thickness increases. Energy-dispersive spectroscopy results reveal an approximately 6 μm-thick element diffusion layer at the bonding interface. Two failure types occur in tensile shear failure: bonding interface peeling failure and bonding edge fracture failure. The maximum force decreases sharply under excessive laser energy or flight distance. The connection strength decreases as the flyer plate thickness decreases.