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.
出处
《材料热处理学报》
EI
CAS
CSCD
北大核心
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)
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
Ni-base alloy
long-term aging
TCP(Topologically Close-Packed) phase
stress-rupture property
stress-rupture activation energy
