稀土元素Y对Ti-600合金热稳定性的影响

Influence of Rare Earth Element Y on the Thermal Stabilities of Ti-600 Alloy

研究了添加与未添加稀土元素Y的合金固溶时效(STA)处理后以及高温长时暴露(600℃/100 h)后毛坯热暴露的室温拉伸性能,结合显微组织等的分析,探讨了Y对合金热稳定性能的影响。结果表明:稀土元素Y的添加可使合金室温塑性提高,STA时室温延伸率提高25%,600℃热暴露100 h后则提高51.9%。热暴露后,添加稀土合金的塑性损失率明显低于不加稀土合金。合金中,稀土元素Y主要以稀土氧化物Y2O3的形式弥散析出。通过细化组织、降低铝当量、改变合金中的位错组态,改善合金的室温塑性,提高合金的热稳定性。

The alloys bars with and without rare earth element Y were solutioned at 1020 °C for 1 h,and aged at 650 °C for 8 h followed by air cooling（STA）.Tensile properties were tested at ambient temperature for the alloy bars before and after being exposed at 600 °C for 100 h.Microstructures for the alloy were observed.And the influence of element Y on thermal stability was also analyzed.The results indicate that the plasticity for the alloy with element Y is superior to that of the alloy without element Y.The elongation for STA sample increases by 25% at ambient temperature,while for the sample exposed at 600 °C for 100 h,the elongation increases by 51.9%.The plasticity loss rate for the alloy with Y is lower than that of the alloy without Y.Rare earth oxides Y2O3 precipitate dispersedly in the alloy during the process of thermal exposure.The plasticity and the thermal stability can be improved by the fine microstructure,the lower Al equivalent,and the modified dislocation configuration.