中文摘要：

采用扫描电镜（SEM）和金相显微镜（OM）组织观察以及能谱（EDS）分析等手段研究了固溶处理温度对第三代镍基单晶高温合金DD10显微组织、枝晶偏析和组织稳定性的影响。结果表明：合金经1290℃/6h固溶后共晶基本消除,1330℃/6h固溶时出现少量微孔,1340℃/6h时则出现初熔。合金经1320℃和1330℃固溶处理后,枝晶偏析程度明显改善。1095℃组织稳定性研究表明：合金经1330℃固溶处理后的由于枝晶偏析程度较小,析出的TCP相数量显著减少,合金的组织稳定性较好。此外,固溶温度对γ′相形貌、体积分数和尺寸的影响不大。

英文摘要：

The effects of solution heat treatment temperature on the microstructures,dendritic segregation and microstructural stability of the third generation Ni-based single crystal superalloy DD10 were investigated by using technics such as SEM（Scanning Electron Microscope）,OM（Optical Microscope） and EDS（Energy Dispersive X-ray Spectroscope） analysis.The results indicate that the eutectic is almost disappeared at 1290℃/6h.Limited amount of microporosities are observed in the interdendritic region at 1330℃/6h and initial melting appears while the solution heat treatment temperature is up to 1340℃.The dendritic segregation degree is decreased after solution heat treatment at both 1320℃ and 1330℃.The results of long-term thermal exposure at 1095℃ indicate that the microstructural stability of DD10 is improved and the amount of TCP phase is decreased significantly after solution heat treatment at 1330℃ due to lower dendritic segregation.Furthermore,the morphology,size and volume fraction of γ′ precipitates are not influenced by solution heat treatment temperature.