长期时效对一种新型镍基合金的组织及持久性能的影响  

Microstructures and high-temperature properties of a new Ni-based superalloy after long-term aging

作　　者：崔彤[1] 王继杰[2] 王磊[1] 杨洪才[1] 赵光普[3] 

机构地区：[1]东北大学材料与冶金学院,辽宁沈阳110006 [2]沈阳航空工业学院材料工程系,辽宁沈阳110034 [3]北京钢铁研究总院,北京100081

出　　处：《材料热处理学报》2006年第5期56-59,共4页Transactions of Materials and Heat Treatment

基　　金：国家"十五"科技攻关项目(冶No.0050390B);辽宁省博士启动基金项目(20051010);辽宁省航空专项基金项目(2005400607)

摘　　要：研究一种新型镍基合金在750、800、850℃长期时效(500-2000h)过程中的组织变化及其对750℃/510MPa持久性能的影响。用扫描电子显微镜对合金显微组织及持久断口进行观察。结果表明:在750-800℃时效该合金有针状TCP相(拓扑密排相)析出,随其析出量的增加,合金基体的强度降低,合金持久断裂趋于从沿晶断裂转为穿晶断裂;800℃、850℃经不同时间时效处理,1000h处持久强度最低,这与γ′相尺寸变化有关;随时效温度的升高,试验合金750℃/510MPa的持久激活能降低,持久强度下降。The relationship between high-temperature stress-rupture properties and microstructure of a Ni-base alloy used in spacecrafts was investigated after long-term aging at temperatures of 750℃,800℃ and 850℃,respectively.The microstructure and stress-rupture fractographs were also analyzed by means of SEM. The results indicate that TCP(Topologically Close-Packed) phase,a harmful phase to Ni-base alloy,precipitated during aging at temperatures from 750℃ to 800℃,and its quantities and sizes increase with the aging time increasing that make the strength of matrix of alloy decrease and the stress-rupture behavior be changed from grain boundary rupture to grain interior.750℃/510MPa stress-rupture strength of the alloy aged at temperatures of 800℃ and 850℃ for 1000h was the lowest,respectively because of the changes of γ′phase size.The higher of aging temperature is,the lower of 750℃/510MPa stress-rupture activation energy will be,so that stress-rupture strength of the alloy is decreased.

关 键 词：镍基合金 长期时效 TCP相(拓扑密排相) 持久性能 持久激活能 

分 类 号：TG132.3[一般工业技术—材料科学与工程] TG142.1[金属学及工艺—合金]