长期时效对定向凝固高温合金DZ8组织与性能的影响  

Effests of Long-term Exposure on Microstructure and Mechanical Property of Directionally Solidified Superalloy DZ8

作　　者：贾新云[1] 谭永宁[1] 张强[1] 张宏炜[1] 黄朝晖[1] 

机构地区：[1]北京航空材料研究院先进高温结构材料国防科技重点实验室,北京100095

出　　处：《材料工程》2009年第S1期279-282,共4页Journal of Materials Engineering

摘　　要：研究了定向凝固高温合金DZ8长期时效后的显微组织和力学性能的变化规律。研究结果表明,合金经900℃长期时效,时效至500h,γ′相由立方形开始向圆形转变;时效至1000h,γ′相则基本上呈圆形,γ′相尺寸稍有长大;随着时效时间的延长,γ′相尺寸逐渐变大,时效至3000h,γ′相大小接近1μm;合金经3000h长期时效后没有出现脆性的TCP相,该合金具有良好的组织稳定性。随着时效时间的增加,室温σb和σ0.2均呈下降趋势,拉伸塑性变化则相反;760℃和980℃持久寿命,时效100h时达到峰值,时效100h后,随着时效时间的延长呈下降趋势。The effects of long-term exposure on microstructure and mechanical property were studied for directionally solidified superalloy DZ8.The results indicate that the morphology of γ′ phase changes from cuboidal to circular after exposed for 500h at 900℃.When exposed for 1000h the morphology of γ′ phase is circle and the size of γ′ phase is about 1μm.No brittle TCP phase appears after exposed for 3000h at 900℃.DZ8 alloy exhibits excellent microstructure stability.With the increasing of long-term exposure time,the tensile strength decreases gradually and there is higher ductility.The stress-rupture life is highest when exposed for 100h at 900℃.And the stress-rupture life decreases gradually after exposed for 100h.

关 键 词：定向高温合金 DZ8 长期时效 组织 性能 

分 类 号：TG132.32[一般工业技术—材料科学与工程]