热处理对Ti_2AlNb合金显微组织及力学性能的影响  

Effect of Heat Treatment on Microstruture and Mechanical Properties of Ti_2AlNb Alloy

作　　者：王伟[1] 曾卫东[1] 冮悦 李冬[1] 郑友平[1] 梁晓波[3] 

机构地区：[1]西北工业大学凝固技术国家重点实验室,陕西西安710072 [2]辽宁工程技术大学,辽宁阜新123000 [3]钢铁研究总院,北京100081

出　　处：《钛工业进展》2015年第1期16-19,共4页Titanium Industry Progress

基　　金：国家973计划资助项目(2007CB613807);教育部"新世纪优秀人才支持计划"项目(NCET-07-0696)

摘　　要：B2相区等温锻造的Ti-22Al-25Nb合金棒材940℃固溶后,在760~840℃时效处理,对其显微组织、拉伸及蠕变性能进行研究。结果表明：不同温度时效处理的显微组织均由初生粗板条状O相、二次析出的细板条状O相和B2基体组成,其中二次析出的O相可以通过时效温度来调节。随着时效温度的升高,Ti2Al Nb合金的室温及650℃高温拉伸强度降低而塑性提高;较低的时效温度（760℃）处理可以获得更好的抗蠕变性能。Ti-22AI-25Nb（at. % ） alloy bars were isothermally forged at B2 phase region and solution treated at 940 ℃ , then aging treated at 760 ℃ to 840 ℃. Then the microstructure evolution and mechanical properties of the bars were studied. The results indicate that the microstructures at different aging temperatures contain primary lamellar O phase, secondary fine lamellar O phase and B2 matrix. The size and volume fraction of secondary fine lamellar O phase can be adjusted through aging treatment. The mechanical properties show that as aging temperature increasing, tile strength including room-temperature and 650 ℃ high-temperature tensile strength decrease, while the ductility increases. The lower aging-temperature （760 ℃ ） has better creep resistance.

关 键 词：Ti2Al Nb基合金 热处理 组织演变 拉伸 蠕变 

分 类 号：TG166.5[金属学及工艺—热处理] TG146.23[金属学及工艺—金属学]