拡散を応用したアルミニウム合金の表面改質

抄録

An applicability of solid diffusion of zinc (Zn) into an aluminum (Al) alloy for surface modification was investigated. A conventional Aluminum (Al) alloy (A5056) containing magnesium (Mg) was used for specimen. Liquefied Zn was plated on the Al alloy surface at a temperature of 450 degree Celsius (deg.) in air atmosphere then was aged for 5 hours was at various temperatures from 300 to 500 deg. As results, the increase in the diffusion distance of Zn from the surface and Al content into the Zn coated layer with the increase in the temperature was found. In addition, segregation of Mg was occurred near the surface and the coated layer was hardened. The tribological properties evaluated with 3 cast iron (FC250) pin in a lubricated condition showed that the difference of the friction coefficient depending on the heat treatment temperature was small and that the wear loss of the disc surface treated at a temperature of 300 deg. decreased. It was estimated that the transfer film containing Zn on the pin surface resulted in the low friction coefficient and the wear loss. Therefore, it is concluded that Zn coating accompanying with a heat treatment is effective means as the surface modification to decrease in the friction coefficient and the wear loss of Al alloy containing Mg.