Plasma surface alloying with molybdenum and carburization of TiAl based alloys
(1.Department of Materials Physics and Chemistry, University of Science and Technology Beijing, Beijing 100083, China2.太原理工人学表面工程研究所，太原030024)
Abstract: A hard layer which is rich in Mo and carbon on the surface of TiAl based alloy was formed after plasma Mo alloying followed by plasma carburization. The process parameters of plasma Mo alloying and plasma carburization were modified. The chemical composition and the thickness of the formed layer are obviously affected by the temperature used during alloying and carburization. The surface layer of TiAl treated by carburization at 1000℃ following Mo alloying at 1125℃ consists of a hard layer with thickness of 20μm and has a graded distribution in chemical composition. The pin-on-disk wear test shows that the frictional properties of TiAl disk treated only by carburization are improved. The TiAl surface treated by both Mo alloying and carburization possesses lower friction coefficient than that of carburized TiAl.
Key words: intermetallics； plasma alloying； plasma carburization； friction coefficient