稀土Y对Ti50Ni50形状记忆合金700℃下恒温氧化行为的影响

Effect of Y addition on the isothermal oxidation behaviour of a Ti50Ni50 shape memory alloy at 700℃

摘要:

本文研究了添加Y对等原子比TiNi形状记忆合金显微组织和700℃恒温氧化行为的影响。结果表明加入稀土Y细化了TiNi合金的晶粒尺寸。Y含量为0.5和1%时Y的加入显著降低了Ti-Ni合金的氧化速率。然而当Y含量为5at%时,含Y的Ti-Ni合金的氧化速率增大

Abstract:

The effect of Y addition on the microstructure and isothermal oxidation behaviour of an equal-atomic Ti-Ni shape memory alloy at 700 ℃ in air was investigated. The results showed that the microstructure of Ti₅₀Ni₅₀ alloy was changed obviously with Y addition and the grains of Ti-Ni alloy was evidently refined. The oxidation rate was significantly reduced by the addition of 0.5 at. %Y and 1.0 at. %Y due to the inhibition of the fast outward diffusion of Ti by the segregated Y ions. However, the oxidation rate was increased by 5 at.%Y addition since the formation of oxide along the Y-rich phase broke the continuity of the TiO₂ scale.