摘要
研究了高温长期时效对一种镍基单晶合金在室温条件下瞬时拉伸强度和在950℃/240MPa条件下持久性能的影响。结果表明:1000℃短期时效100h,合金室温拉伸强度σb与屈服强度σ0.2与时效前相比没有明显变化,时效超过500h后σb和σ0.2开始显著下降,时效超过1000h后,σb和σ0.2随时效时间延长下降幅度减小;短期时效100h和500h样品在950℃/240MPa条件下的持久寿命大幅度降低,延伸率快速上升,时效时间超过1000h后,持久寿命的下降幅度减小,合金的持久寿命与延伸率均趋于稳定。长期时效后γ'相形貌改变及γ/γ'相界面高密度位错网的破坏是时效后合金室温及高温持久性能持续降低的主要原因。
The influences of high temperature long-term aging on the tensile strength at room temperature and stress rupture property at 950℃/240MPa were investigated for a new nickel base single crystal alloy. The results show that the tensile strength of specimens after aging at 1000℃ for no more than 500h does not significantly decline, whereas the tensile yield strength greatly reduces compared with standard heat treatment specimens. The tensile strength continuously declines with the increasing for the aging specimens more than 100Oh. Meanwhile, the stress rupture lives of specimens after aging 1000h decreases substantially and the elongation rises rapidly. Furthermore, the stress rupture lives decline slowly and elongation is tending towards stability. The change of the γ＇ morphology and disappearance of the γ/γ＇ interfacial dislocation net are the main reasons for the decrease of mechanical properties of the high temperature long-term aging specimens.
出处
《航空材料学报》
EI
CAS
CSCD
北大核心
2014年第5期12-16,共5页
Journal of Aeronautical Materials
关键词
镍基单晶
长期时效
拉伸强度
持久性能
nickel base single crystal alloy
long-term aging
tensile strength
stress rupture
