合金元素Al对Cr-20Nb合金高温抗氧化性能的影响

摘要

采用机械合金化+热压烧结工艺制备了掺杂合金元素Al的Cr-20Nb合金,研究Al对Cr-20Nb合金在1100℃和1200℃下高温抗氧化性的影响.结果表明,合金元素Al能促进Cr-20Nb合金氧化时生成AlNbO_4复合型氧化物,该复合型氧化物能有效抑制Cr_2O_3的挥发反应,从而改善Cr_2O_3氧化层的致密性,并提高氧化膜的粘附性,导致合金抗氧化性显著提高.不同Al含量的Cr-20Nb合金氧化增重均近似于抛物线规律.%The influence of Al on the high temperature oxidation of Cr-20Nb alloys, which were fabricated by mechanical alloy and hot press, has been studied at 1100℃ and 1200℃ in air, respectively. The results indicate that the proper addition of Al promote the formation of AlNbO_4 complex oxide which retard the volatilization of Cr_2O_3 scales. Thus the compactability of Cr_2O_3 scales and the adherence of the oxide scale are improved, which lead to the oxidation resistance remarkably improved. The results also show that the oxidation kinetics of Cr-20Nb alloys with different Al content is similar to parabolic law.