Tribological Behaviour Of Double-Glow Plasma Zirconium-Yttrium Alloying On Gamma-Tial

A Zr-Y alloyed layer was prepared onto the surface of gamma-TiAl using double-glow plasma surface alloying technique (DG technique). The results showed that the Zr-Y alloyed layer was comprised of deposited sub-layer and diffused sub-layer, with a total layer thickness of about 20 mu m. The nano-indentation test result showed that the nano-hardness of Zr-Y alloyed layer was 2.35 times that of gamma-TiAl. The scratch test was carried to evaluate the adhesion strength of Zr-Y alloyed layer. The tribological behaviours were investigated both at ambient temperature and 500 degrees C. Under dry sliding condition, the friction coefficient of the Zr-Y alloyed layer was lower than that of the gamma-TiAl. The specific wear rate of gamma-TiAl in the presence of Zr-Y alloyed layer was approximately one fifth that in the absence of the alloyed layer. The excellent wear resistance of Zr-Y alloyed layer could be attributed to the high hardness or load-carrying ability.