抽拉速率对DD15单晶高温合金组织和力学性能的影响  

Effect of Withdrawal Rate on Microstructures and Mechanical Properties of DD15 Single Crystal Superalloy

作　　者：史振学[1] 刘世忠[1] 李嘉荣[1] SHI Zhen-xue;LIU Shi-zhong;LI Jia-rong(Science and Technology on Advanced High Temperature Structural Materials Laboratory,Beijing Institute of Aeronautical Materials,Beijing 100095,China)

机构地区：[1]北京航空材料研究院先进高温结构材料重点实验室,北京100095

出　　处：《铸造》2020年第8期803-807,共5页Foundry

摘　　要：采用不同的抽拉速率制备了第四代单晶高温合金DD15,研究了抽拉速率对合金组织和力学性能的影响。研究结果表明,随着抽拉速率的增加,铸态合金的一次枝晶间距和二次枝晶间距减小,共晶含量增加,枝晶干和枝晶间的γ′相尺寸减小。不同抽拉速率合金热处理后都未见残余共晶,随着抽拉速率增加,γ′相尺寸稍有减小,γ′相立方化程度增加。合金的拉伸性能和持久性能随着抽拉速率的增加而升高。The fourth generation single crystal superalloy DD15 was fabricated with different withdrawal rates and the effect of the withdrawal rate on the microstructures and mechanical properties of the alloy was investigated. The results show that, with an increase in the withdrawal rate, the primary and secondary dendrite arm spacings in the as-cast microstructure of the alloy decrease, the volume fraction of eutectic increases, and the size of γ′ phase in the dendrite core and in the interdendrite decreases;after heat treatment, there is no residual eutectic in the alloy, and with increasing the withdrawal rate, the size of γ′ phase decreases slightly, the shape of γ′ phase tends to be more cubic. The results also reveal that the tensile strength and stress rupture life of DD15 alloy enhance with increasing the withdrawal rate.

关 键 词：DD15 单晶高温合金 抽拉速率 

分 类 号：TG132.32[一般工业技术—材料科学与工程]