| The effects of third elements in the TiAl on the mechanical property and the oxidation resistance of aluminized coating layer formed on the TiAl have been studied. With the basic alloy of TiAl, the ternary alloys of TiAl-2 at%X were prepared X being Nb, Cr, Fe and V. All the specimens were pack aluminized in the same condition of high activity process. The toughness of the coating layer was evaluated by vicker`s hardness test, and the oxidation resistance was evaluated by isothermal and cyclic oxidation tests. The third element added in the TiAl affected the property of the TiAl₃ coating layer. Among the alloying elements evaluated, Nb showed the moat positive effects on the coating thickness, coating microstructure, and toughness and stability of the coating layer. The oxidation resistance of aluminized TiAl alloy was influenced by the property of coating layer. The best oxidation resistance was obtained in the aluminized TiAl alloy with Nb which has most tough and thick coating layer. However, further studies are required to clarify the exact role of Nb on the mechanism of coating process and on the mechanical property of coating layer. |
|
