摘要
采用预合金粉末热等静压工艺制备名义成分为Ti-22Al-24Nb-0.5Mo(原子百分数)的粉末Ti2AlNb合金,对粉末合金、经热处理的粉末合金和同种成分的熔铸Ti2AlNb合金进行了压缩实验。结果表明,粉末Ti2AlNb合金具有与熔铸变形合金相当的变形能力,热处理对粉末Ti2AlNb合金的变形能力没有明显的影响,粉末合金在低温和高应变速率下的变形抗力更低,不易开裂。采用典型粉末成型工艺制备粉末Ti2AlNb热变形坯料,在两相区进行了不同变形量的墩粗和拔长热变形。结果表明,粉末Ti2AlNb坯料变形后没有宏观裂纹,变形均匀。拉伸实验结果表明,变形后经热处理的粉末Ti2AlNb合金表现出更好的拉伸性能。
Powder metallurgy(PM) Ti2 Al Nb alloy of Ti-22Al-24Nb-0.5Mo(atomic fraction, %) was prepared from pre-alloyed powder using hot isostatic pressing(HIPing). Compression tests of PM Ti2 Al Nb alloy, heat treated PM Ti2 Al Nb alloy and wrought Ti2 Al Nb alloy with the same chemical composition were conducted on Gleeble-3800 testing machine. The testing temperatures were from 930 oC to 1050 oC, strain rates varied from 0.001 s-1to 10 s-1, and engineering strain was about 50% for each compression. The results show that the deformability of PM Ti2 Al Nb alloy is comparable to that of wrought alloy, and heat treatment has no obvious effect on the hot workability of PM Ti2 Al Nb alloy. The high temperature flow behavior of Ti2 Al Nb alloys prepared by different fabrication routes is similar in this work, while processing windows for PM Ti2 Al Nb alloy is broader than casting alloys especially at low temperature or relative high strain rate. PM Ti2 Al Nb billets for hot deformation were prepared by a typical powder metallurgy process, and were upset or drawn out to different deformation in two- phase region. Macrostructure of deformed PM Ti2 Al Nb billets were observed, no macro crack was found in deformed PM Ti2 Al Nb billets and the deformation was uniform. The results of tensile tests show that the deformed PM Ti2 Al Nb alloy after heat treatment presents better tensile properties.
出处
《材料研究学报》
EI
CAS
CSCD
北大核心
2015年第6期445-452,共8页
Chinese Journal of Materials Research
基金
国家高技术研究发展计划2013AA031606资助项目~~
关键词
金属材料
Ti2AlNb合金
粉末冶金
热等静压
热机械加工
metallic materials,Ti2Al Nb alloys,powder metallurgy,hot isostatic pressing,thermal mechanical processing
