中國有色金屬學(xué)報(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 26 No. 4 April 2016 |
（Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China）
Abstract:A Ti(Al,Si)3 diffusion coating was prepared on γ-TiAl alloy by cold sprayed Al-20Si alloy coating, followed by a heat-treatment. The isothermal and cyclic oxidation tests were conducted at 900 °C for 1000 h and 120 cycles to check the oxidation resistance of the coating. The microstructure and phase transformation of the coating before and after the oxidation were studied by SEM, XRD and EPMA. The results indicate that the diffusion coating shows good oxidation resistance. The mass gain of the diffusion coating is only a quarter of that of bare alloy. After oxidation, the diffusion coating is degraded into three layers: an inner TiAl2 layer, a two-phase intermediate layer composed of a Ti(Al,Si)3 matrix and Si-rich precipitates, and a porous layer because of the inter-diffusion between the coating and substrate.
Key words: Ti(Al,Si)3 diffusion coating; γ-TiAl alloy; cold spray; heat-treatment; high temperature oxidation
