摘要
研究了固溶、固溶时效、短时退火对Ti-18Nb-10Zr(at%)合金微观组织和超弹性的影响。采用室温拉伸测试了合金超弹性;借助X射线衍射(XRD)、电子背散射衍射(EBSD)、透射电子显微镜(TEM)对微观组织、相变行为进行了观察与分析。结果表明,冷轧态Ti-18Nb-10Zr合金,800℃固溶后,发生了完全再结晶,由β相和细小的无热ω相组成,回复应变约为2.65%;再在350℃时效后,由于等温ω相尺寸和体积分数显著增加,急剧降低了合金Ms,应力-应变曲线未呈现超弹性;650℃短时退火后,合金基本完成再结晶,由单一的β相组成,平均晶粒尺寸约为10μm,晶粒细化改善了合金超弹性,回复应变约为2.86%。
Effects of solution treatment, solution-aging and short time annealing on microstructure and superelasticity of Ti-18Nb-10Zr(at%) alloy were investigated.Tensile tests at room temperature were conducted to evaluate the superelasticity .X-ray diffraction(XRD), electron backscatter diffraction ( EBSD ) , transmission electron microscope ( TEM ) were applied to analyze the microstructure and phase transformation.The results show that Ti-18Nb-10Zr alloy recrystallizes fully and consists of βphase and fine athermal ωphase when solutioned at 800 ℃, and the stress-strain curve shows partial recovery with 2.65% recovery strain.Then aged at 350 ℃, superelasticity hardly occurs on account that the marked increase of size and volume fraction of isothermal ωphase leads to the drastic decrease in the martensite start temperature (Ms).Ti-18Nb-10Zr alloy recrystallizes and consists of βphase with average grain size being 10 μm when annealed at 650 ℃for short time.The superelasticity is improved because of grain refinement and the recovery strain is about 2.86%.
出处
《金属热处理》
CAS
CSCD
北大核心
2015年第3期92-95,共4页
Heat Treatment of Metals
基金
国际科技合作与交流专项(2013DFG52920)
