Thermo-Span合金在650℃长期时效稳定性  

Long-term thermal stability of Thermo-Span alloy at 650 ℃

作　　者：胡轶嵩[1] 于连旭[2] 杨连忠[3] 李晓欣[1] 王志宏[1] 

机构地区：[1]沈阳发动机设计研究所,辽宁沈阳110015 [2]中国科学院金属研究所,辽宁沈阳110016 [3]中铝沈阳有色金属加工有限公司,辽宁沈阳110102

出　　处：《材料热处理学报》2013年第8期55-59,共5页Transactions of Materials and Heat Treatment

基　　金：国家重点基础研究发展计划资助项目(2010CB63206)

摘　　要：对标准热处理和650℃长期时效下的低膨胀Thermo-Span合金的组织和性能进行观察和分析,结果表明:650℃时效1000 h后,合金块状和棒状Laves相无明显变化,但晶界析出相数量有所增加;晶内小条块状相聚集析出的区域更多,γ'相由约10 nm长大到约30 nm。合金的室温拉伸强度稍有下降,降幅约为8%,塑性基本不变;650℃拉伸强度降低约5%,塑性变化不大。合金的光滑持久寿命降低约41%,持久塑性明显提高,时效后合金仍无缺口敏感性。Microstructure and properties of oxidation resistant low thermal expansion Thermo-Span alloy unexposed and after ageing at 650 ℃ for 1000 h were investigated. The results show that after ageing at 650 ℃ for 1000 h, the blocky and bar-like Laves phase shows no significant difference compared with that of the unexposed alloy, but the grain boundary precipitation is promoted. There are more zones precipitated with lamellar phase within the grains, and the diameter of-,/＇ phase grows from 10 nm to 30 nm in the aged alloy. The room temperature tensile strength of the aged alloy decreases by nearly 8% and the ductility is kept the same. The tensile strength at 650 0C decreases by nearly 5% and the ductility is hardly varied. The stress rupture life of smooth bars are shortened by nearly 41% and the rupture ductility is markedly increased, and the aged alloy shows no notch sensitivity. As a conclusion, Thermo-Span alloy shows good thermal stability at 650 ℃.

关 键 词：低膨胀 Thermo-Span合金 时效 热稳定性 

分 类 号：TG156.92[金属学及工艺—热处理]