Experimental Investigation on Laser Impact Welding of Fe-Based Amorphous Alloys to Crystalline Copper

Recently, amorphous alloys have attracted many researchers' attention for amorphous structures and excellent properties. However, the welding of amorphous alloys to traditional metals in the microscale is not easy to realize in the process with amorphous structures unchanged, which restrains the application in industry. In this paper, a new method of welding Fe-based amorphous alloys (GB1K101) to crystalline copper by laser impact welding (LIW) is investigated. A series of experiments was conducted under different laser energies, during which Fe-based amorphous alloys and crystalline copper were welded successfully by LIW. In addition, the microstructure and mechanical properties of welding joints were observed and measured, respectively. The results showed that the surface wave and springback were observed on the flyer plate after LIW. The welding interface was straight or wavy due to different plastic deformation under different laser energies. The welding interface was directly bonded tightly without visible defects. No visible element diffusion and intermetallic phases were found in the welding interface. The Fe-based amorphous alloys retained amorphous structures after LIW under the laser energy of 835 mJ. The nanoindentation hardness across the welding interface showed an increase on both sides of the welding interface. The results of the lap shearing test showed that the fracture position was on the side of copper coil.