微量稀土提高铂的高温持久强度的机理

The Mechanisms to Improve the High-Temperature Tensile Strength of Platinum with Rare Earth Elements

铂中加入双稀土元素后,其高温持久强度及蠕变断裂激活能得到很大提高。1300℃时合金的持久强度断裂时间是纯铂的23～360倍。研究表明,PtYLu合金熔炼过程中形成PtY(Lu)化合物;高温内氧化作用下形成Y_2O_3和Lu_2O_3氧化物;高温长时间作用下形成Pt_2Y(Lu)化合物。大部份稀土富集在晶界上。本文对微号双稀土无素提高Pt高温持久强度的机理讲行了探讨。

It has been found that the high-temperature tensile strength and creep activation energy were increased when the binary-rare earth elements had been added into platinum. At 1300℃, the time of failure of the alloys is 23～360 times longer than that of Pt. It was demonstrated that the PtY (Lu) was formed during melting, Y_2O_3 and Lu_2O_3were formed at high-temperature. The Pt_2Y(Lu)was formed at high temperature and heat preservation for a long time. Most of rare earth elements were concentrated on the grain boundary of PtYLu alloy. The mechanism of the effect of rare earth elements on the platinum was discussed.