粉末冶金Ti-5Al-2.5Sn ELI合金显微组织研究  

Microstructure of Powder Metallurgical Ti-5Al-2.5Sn ELI Alloy

作　　者：邬军[1,2] 徐磊[1] 雷家峰[1] 刘羽寅[1] 

机构地区：[1]中国科学院金属研究所,辽宁沈阳110016 [2]中国工程物理研究院,四川绵阳621900

出　　处：《稀有金属材料与工程》2015年第9期2255-2259,共5页Rare Metal Materials and Engineering

摘　　要：采用包套热等静压工艺制备了粉末冶金Ti-5Al-2.5Sn ELI（extra low interstitial）合金,研究了热等静压温度、粉末粒度、后续热处理温度对合金显微组织的影响。当热等静压温度在800℃时,粉末体压坯显微组织保持颗粒形态,致密度为99.2%;当温度在900~940℃时,显微组织演变为完全致密、细小的等轴晶。在α相区热等静压温度下,包套中的Fe在基体中的扩散不明显;在α＋β、β相区温度下,Fe在β相中向基体快速扩散,影响合金表面质量。粉末粒度越大,合金的平均晶粒尺寸越大,残留孔隙较多。在α相区热处理,显微组织仍为细小等轴晶;当温度升至1000℃时,出现热致孔隙。Powder metallurgical Ti-5Al-2.5Sn ELI（extra low interstitial） alloy was prepared in a container by hot isostatic pressing（HIP）. The effects of HIP temperature, particle size of powders and heat treatment temperature on the microstructure have been investigated. Particle morphology would be observed in the powder compact sample, with its relative density of 99.2% at the holding temperature of 800 °C. Within the temperature ranging from 900 to 940 °C, the microstructure has developed into fully dense and fine equiaxed grains. When the sample is compacted in α phase region, significant diffusion of Fe can be hardly observed at the boundary of the container and the compact; in α＋β or β phase region, fast diffusion of Fe in β phase may do harm to surface quality of the powder compact. The mean grain size and the residual porosity of PM alloy increase with the increase of powders＇ particle size. There is no obvious change in the microstructure of PM alloy after heat treatment in α phase region. Temperature induced porosity doesn＇t appear until the heat treatment temperature rises up to 1000 °C.

关 键 词：粉末冶金 热等静压 Ti-5Al-2.5Sn ELI 显微组织 

分 类 号：TG146.23[一般工业技术—材料科学与工程]