화학공학소재연구정보센터
Journal of Materials Science, Vol.43, No.2, 788-792, 2008
The effect of quenching medium on the wear behaviour of a Ti-6Al-4V alloy
The aerospace alloy, Ti-6Al-4V is a difficult material to machine, and, in general, shows poor wear resistance due to the soft, ductile properties of the alloy. In this study, the Ti-6Al-4V alloy has been heat treated to a temperature above and below the beta-transus temperature and then quenched using a medium of oil, water or liquid nitrogen to change the surface wear behaviour of the alloy. The results showed that no significant change in microstructure and surface properties was achieved when the alloy was heated to 750 degrees C and then quenched in liquid nitrogen. However, when the alloy was heated to 1,000 degrees C (above the beta-transus), the hardness of the titanium alloy significantly increased from 400 VHN to about 800 VHN, but the wear resistance of the alloy did not improve. In fact, the wear resistance of the alloy decreased as the surface hardness increased, and this change in wear behaviour was attributed to a change in the mechanism of wear from plastic deformation to brittle-fracture of the surface.