Laser surface strengthening process of Al-Si base alloy

With a laser beam, the surface remelting/resolidifying treatment of ZL108 a lloy was studied. Test results showed that a compact remelting layer was ob tained with appropriate laser processing conditions and a suitable surface coating for laser energy absorption. The eutectic silicon phase in the lase r-treating zone changed from the shape of thick-plate (stripe) into the ver y small grains, the structure was extremely fined, the hardness and wear re sistance were improved greatly compared with that of the base alloy. A lase r -treating layer, which is 3.5 mm thick and 5 mm wide, could be obtained.