Research on the laser welding of Al-Li alloy

The laser welding of domestic 8090 Al-Li alloy was studied. The experiments show that good welding joint can be gained. The surface of welding joint is even and smooth at proper technical parameters. Single side welding can be through Al-Li alloy plate of 0.70 mm in thickness while double side welding can be through 1.4 mm thick one. Optical microscope analysis shows that the welding joint is combined well. The welding line is narrow and has fine grain structure. The heat-affected zone is small. Electron probe microanalysis shows that there is hardly change in their composition of the welding line and the heat-affected zone. But the thermal crack is produced easily and the delayed crack is also created easily. So the stress releasing treatment should be after welding.