铂-稀土合金的高温氧化与挥发

High Temperature Oxidation and Volatilization of the Pt RE Alloys

研究了铂和铂稀土（以下简称ＰｔＲＥ）合金在７００～１４００℃相对静止空气中的氧化与挥发，其动力学曲线不仅符合Ｆｉｃｋ定律，而且与ＪＭＡ方程吻合较好，在１１００℃以上Ｐｔ的挥发很大，添加稀土元素后大大改善了Ｐｔ的抗氧化能力，Ｐｔ的挥发主要取决于表面扩散，而ＰｔＲＥ合金的氧化受控于晶界扩散。

The oxidation and volatilization of the platinum and Pt RE alloys in the temperature range 700～1400 ℃ in relative still open air have been studied. The results show that the dynamic curves not only satisfy the Fick law but also accord with the J M A equation. The volatilization of the pure platinum above 1100 ℃ is grave, while the oxidation resistant properties are greatly improved by addition of the rare earth elements. The volatilization of pure platinum mainly depends upon the surface diffusion, meanwhile for the platinum rare earth alloys it is controlled by the grain boundary diffusion.