アルミナ短繊維強化A6063アルミニウム合金の拡散接合

抄録

The Al-Mg-Si A6063 alloy reinforced with alumina short fibers has been diffusion-bonded with the bond interface perpendicular to the direction of fibers, i.e., direction of the highest strength, and the effects of surface treatments, bonding parameters (temperature and pressure) and insert metals on the bond strength have been systematically investigated. The surface treatments used were (i) electropolishing, (ii) turning in a lathe and (iii) wire brushing. On the faying surface finished by (i), fibers protruded from the surface of the matrix metal were observed, and their height increased with electropolishing time. Treatment (i) resulted in bond strength considerably higher than (ii) and (iii), though the bond strength was decreased with the increase in the protruded height of fibers more than 8 μm. This decrease in the bond strength was probably due to the suppression of intimate contact between matrix surfaces by protruded fibers which were broken by bonding pressure and laid on the bond interface. In the case of (iii), a lot of fine fragments of the fiber broken by the wire brushing and an increase in iron content were observed at the bond interface. These fragments of the fiber and increase in iron content seem to have harmful effects on the bond strength, since (iii) resulted in the lowest bond strength. In the case of (ii), the fine fragment of the fiber was observed, but no increase in iron content could be found. The application of insert metals of Al-Cu-Mg A2017 alloy, copper and silver foils extended the range of bonding conditions to obtain high bond strength, and decreased the bonding deformation; e.g., in the case of (i), bond strength not less than the tensile strength of the base metal was obtained with small bonding deformation by using the insert metal of A2017 alloy or copper.