アルミニウム合金急冷凝固粉末を溶射した6063アルミニウム合金押出材のNd-YAGレーザによる表面改質 Surface modification of extruded 6063 aluminum alloy sprayed with atomized powder of aluminum alloys using Nd-YAG laser
Laser remelting process with Nd–YAG laser is investigated in order to improve the adhesion and wear resistance of low pressure plasma sprayed layer on the surface of aluminum extruded plate (6063) using the atomized powder of Al–50 mass%Fe, Al–15 mass%Fe–17 mass%Si and Al–50 mass%Si. The effects of pulse energy of laser beam on the microstructure, the microhardness, and the wearing rate of these laser-remelted layers are examined. Laser-remelted layer has smoother surface and better adhesion than those of the layer as sprayed. The microhardness of laser-remelted layer is kept constant toward the depth direction. In the microstructure of laser-remelted layer of Al–50 mass%Fe, fine needle-like Al<sub>3</sub>Fe and massive Al<sub>2</sub>Fe is dispersed. The microhardness increases with a decrease of the pulse energy of laser beam, but the wearing rate of laser-remelted layer increases due to the initiation of cracking. In the matrix of Al–15 mass%Fe–17 mass%Si laser-remelted layer, ultra fine needle-like and massive (Al, Fe, Si) ternary crystals are aggregated. In the microstructure of Al–50 mass%Si laser-remelted layer is ultra fine hypereutectic. Microhardnesses of these layers which are remelted at any pulse energy are HV250–350, HV150–200, respectively, and these wearing rates of them are 1/7 or less than anodized surface.
軽金属 47(1), 21-27, 1997-01-30
The Japan Institute of Light Metals