Ru对第四代镍基单晶高温合金DD22长期时效组织演化的影响  

Effect of Ru on microstructure evolution of the fourth generation nickel-based single crystal superalloy DD22 during long-term aging

作　　者：赵云松 杨昭 陈瑞志 张剑 骆宇时 刘丽荣[3] ZHAO Yunsong;YANG Zhao;CHEN Ruizhi;ZHANG Jian;LUO Yushi;LIU Lirong(Science and Technology on Advanced High Temperature Structural Materials Laboratory,AECC Beijing Institute of Aeronautical Materials,Beijing 100095,China;Aviation Military Representative Office of Army Equipment Department in Beijing,Beijing 100041,China;School of Materials Science and Engineering,Shenyang University of Technology,Shenyang 110870,China)

机构地区：[1]中国航发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 [2]陆装驻北京地区航空军代表室,北京100041 [3]沈阳工业大学材料科学与工程学院,沈阳110870

出　　处：《材料工程》2022年第9期127-136,共10页Journal of Materials Engineering

基　　金：国家自然科学基金项目(52001297)。

摘　　要：利用透射电镜和场发射扫描电镜研究了两种不同Ru含量(3%和5%,质量分数)的第四代镍基单晶高温合金DD22在1130℃长期时效过程中γ′相形貌演化、TCP相析出和界面位错网的演化情况。研究结果表明:在完全热处理后5Ru合金比3Ru合金的γ′相尺寸更小,形状更规则,γ/γ′相界面的错配度更大,高Ru含量使合金Re,Mo等元素出现反分配现象;5Ru合金在1130℃长期时效过程中γ′相粗化速率、溶解速率和形筏速率均低于3Ru合金;5Ru合金在长期时效1000 h后仍没有TCP相析出,而3Ru合金在时效50 h后便析出TCP相,随着长期时效时间延长,TCP相数量增多,尺寸增大;与3Ru合金相比,长期时效1000 h后5Ru合金γ′/γ界面位错网更加致密和规则;综上所述,Ru的元素反分配作用和低的扩散系数使5Ru合金比3Ru合金表现出更高的组织稳定性。The morphological evolution ofγ′phase,the precipitation of TCP phases and the evolution of the interfacial dislocation networks in DD22 nickel-based single crystal superalloys with different Ru contents(3%and 5%,mass fraction)were investigated by transmission electron microscopy and field emission scanning electron microscopy during long-term aging at 1130℃.The results show thatγ′phase of 5Ru alloy are smaller in size and more regular in shape than that of 3Ru alloy.The mismatch ofγ/γ′phases is larger in 5Ru alloy,and the high content of Ru causes the reverse distribution of elements such as Re and Mo.During long-term aging at 1130℃,the coarsening rate,dissolution rate and rafting rate ofγ′phase in 5Ru alloy are lower than those of 3Ru alloy.There is still no TCP phase precipitation in 5Ru alloy after long-term aging for 1000 h,while a small amount of TCP phase is precipitated in 3Ru alloy after long-term aging for 50 h.With the prolongation of long-term aging time,the number and size of TCP phases both increase.Compared with 3Ru alloy,the interfacial dislocation networks of 5Ru alloy are denser and more regular after long-term aging for 1000 h.Above all,the reverse distribution of elements and low diffusion coefficient of Ru make 5Ru alloy exhibit higher microstructural stability than 3Ru alloy.

关 键 词：DD22镍基单晶高温合金 Ru含量 长期时效 位错网 组织稳定性 

分 类 号：TG132.3[一般工业技术—材料科学与工程]