固溶温度对镍基单晶高温合金蠕变性能的影响

Influence of Solution Temperature on Creep Property of Single Crystal Nickel Based Super Alloy

通过对一种含2%Ru镍基单晶高温合金高温低应力及中温高应力条件下的蠕变性能测试和组织形貌观察,研究固溶温度对合金蠕变性能的影响。结果表明,铸态合金的成分偏析较严重,组织结构不均匀,在初熔温度以下,逐步提高固溶温度可以较大幅度地提高合金的高温和中温蠕变性能,蠕变时间增幅分别为63.7%、40.3%。测定合金在高温/低应力条件下的蠕变激活能493.4 kJ/mol,应力指数4.1。表明合金在高温低应力条件下的蠕变变形机制是位错在基体通道中滑移和位错攀移越过γ'相。

By means of creep properties measurement and microstructure observation at high temperature/ lower stress and intermediate temperature/high stress of a single crystal nickel based super alloy containing of 2% Ru element, the influence of solution temperature on creep property is studied in the paper. The results show that the composition segregation of cast alloy is serious and the microstructure of the cast alloy is heterogeneous, and the creep property of the alloy is improved greatly under the incipient melting temperature, the creep time is increased by 63.7% and 40.3% at high/intermediate temperature respectively. The creep activation energy （Q） is 496.4 k J/tool and stress exponent n = 4.1 at high temperature/lower stress. Results show that the dislocations slipping in the matrix and climbing over the phase are thought to be the main deformation mechanisms of the alloy at high temperature.