高Ru和高Cr对镍基高温合金组织稳定性的影响

Effects of high Ru and high Cr on the microstructural stability of Ni-base superalloys

在多组元的镍基高温合金中分别和同时加入高Cr和高Ru,经固溶处理后,在800～1100℃下进行10～1300h时效处理,观察组织并分析Ru、Cr以及二者交互作用对合金组织稳定性的影响.结果表明:在无Cr和Ru的合金中,经过1000℃/1300h时效处理后无TCP相析出;加入高Cr的合金仅20h就在晶界发现了TCP相,50h后在枝晶干出现TCP相;在1000℃时效,TCP相比其他温度更易析出.在同时加Cr和Ru的合金中,经过1000℃/1000h时效后并未发现TCP相的析出.这说明高含量的Cr促进了TCP相的形成,而高Ru的添加在高Cr合金中也能有效地抑制TCP相的析出,提高组织稳定性.

Four experimental multi-component Ni-base superalloys were designed to investigate the influence of high Ru and high Cr on the microstructural stability at high temperature. These alloys were solution-treated and then aged at 800 - 1 100 ℃ for 10 - 1 300 h. The experimental results showed that no TCP phases were found in the Ru-free or Cr-free alloy after aging at 1 000 ℃ for 1 300 h. For the alloy with high level of Cr addition, TCP phases were observed to precipitate along grain boundaries and in dendrite cores after 20 h and 50 h at 1000 ℃, respectively; after aging at 1000 ℃ for 1000 h, no TCP phases were observed in the alloy with high levels of Cr and Ru additions. It is indicated that the high level of Cr addition promotes the precipitation of TCP phases, while high level of Ru addition efficiently lowers the propensity for the formation of TCP phases in the high Cr-containing alloy, and thus improve the microstructural stability.