两种镍基单晶高温合金组织演变和再结晶行为  

Microstructure evolution and recrystallization behavior of two nickel-based single crystal superalloys

作　　者：徐福泽 蔺永诚[1] 马德新 何道广 赵运兴 李侣 程博文 邓阳丕 XU Fuze;LIN Yongcheng;MA Dexin;HE Daoguang;ZHAO Yunxing;LI Lyu;CHENG Bowen;DENG Yangpi(School of Mechanical and Electrical Engineering,Central South University,Changsha 410083,China;Shenzhen Wedge Central South Research Institute Co.,Ltd.,Shenzhen 518045,Guangdong,China;Powder Metallurgy Research Institute,Central South University,Changsha 410083,China)

机构地区：[1]中南大学机电工程学院,长沙410083 [2]深圳市万泽中南研究院有限公司,广东深圳518045 [3]中南大学粉末冶金研究院,长沙410083

出　　处：《材料工程》2025年第1期110-120,共11页Journal of Materials Engineering

基　　金：国家自然科学基金项目(91860103,92060104);中南大学研究生科研创新项目(自主探索)(1053320184004);深圳市海外高层次人才资金资助项目(KQTD2015032716463668);广东省引进创新创业团队项目资助项目(607264877417)。

摘　　要：以单晶高温合金CMSX-4和DD5为研究对象,设计并制备了一种含5级平台的单晶试板铸件,选取晶体取向基本相同的铸件研究其在经1300℃/2 h和1310℃/4 h两种固溶热处理后的再结晶行为。结果表明:CMSX-4比DD5具有更强的再结晶倾向。经1300℃固溶热处理后,CMSX-4单晶试板在第2~5级平台下端转角处均出现了再结晶现象,且随着固溶热处理温度的升高,再结晶的面积越大。而DD5单晶试板经1300℃固溶热处理后并未出现再结晶现象,当固溶温度升至1310℃时,仅在第4级外侧平台发现了较小面积的再结晶。铸态和固溶热处理态的CMSX-4合金显微缩孔和共晶组织含量均大于DD5合金。更高含量的共晶组织和显微缩孔为CMSX-4铸件提供了更多的再结晶形核位置和数量,而高于γ′相溶解温度的固溶热处理减弱了粗大γ′相对再结晶长大的钉扎阻碍作用,高熔点的碳化物以及残余共晶成为阻碍再结晶长大的重要影响因素。此外,高含量的Co元素降低了CMSX-4合金的层错能,使其表现出更高的再结晶倾向。This study focuses on the single crystal(SC)superalloys CMSX-4 and DD5,designing and fabricating a SC test plate casting with five distinct stages.Castings with the same crystal orientation are selected to investigate their recrystallization(RX)behavior after solution heat treatment at 1300℃ for 2 h and 1310℃ for 4 h.The results indicate that CMSX-4 exhibits a stronger tendency for RX compared to DD5.Following a solution heat treatment at 1300℃,the CMSX-4 SC test plate displayed RX at the lower corners of 2-5 stage platforms,with the extent of RX expanding as the solution heat treatment temperature rose.Conversely,no RX was detected in the DD5 SC test plate post-treatment at 1300℃.Elevating the solution temperature to 1310℃ results in only a minor area of RX on the outer platform of the fourth stage in the DD5 SC test plate.The micro-shrinkage porosity and eutectic content of the as-cast and solution heat treated CMSX-4 alloy are both higher than those of the DD5 alloy.The higher content of eutectic and micro-shrinkage porosity provides more nucleation sites and quantities for RX in the CMSX-4 alloy,while the solution heat treatment temperatures above the γ'phase dissolution temperature weakens the pinning effect of coarse γ'phase on RX growth,and high melting point carbides and residual eutectic become important factors hindering RX growth.In addition,the high content of Co element reduces the stacking fault energy of the CMSX-4 alloy,making it with a high recrystallization tendency.

关 键 词：单晶高温合金 CMSX-4 DD5 再结晶 塑性应变 

分 类 号：TG146[一般工业技术—材料科学与工程]