摘要
研究了Ti-5321合金不同热处理制度下的α相析出行为。结果表明:β单相区固溶后的组织为单一的β晶粒组织,α/β两相区固溶后的组织中含有β基体和分布于β基体的初生α相。这两种组织在后续的时效过程中均析出细小针状次生α相,且其尺寸随时效温度的升高而增加,不同的是,β单相区固溶加时效样品的晶界处析出的次生α相的尺寸明显大于晶内次生α相。合金从910℃缓冷过程中α相首先在晶界处析出,随后片层α集束以晶界α相为核心形核并长大,随后的520℃时效过程中析出尺寸细小的针状次生α相。电子背散射衍射(EBSD)分析表明,缓冷过程中,在两侧β晶粒有平行{110}面的晶界上析出一种α相变体,这种变体与两侧的β晶粒均保持Burgers取向关系,以这种变体为形核核心向晶界两侧生长形成片层α相。在两侧β晶粒没有平行{110}面的晶界上会析出多种α相变体,每种变体只与其中一侧的β晶粒保持Burgers取向关系,且会以这种变体为形核核心向与其保持Burgers取向关系的β晶粒一侧生长形成片层α相。
The precipitation behavior ofαphase of Ti-5321titanium alloy during heat treatment was studied.The results show that,the alloy in theβsolution treated condition shows a singleβphase microstructure,while the microstructure of the alloy in theα/βsolution treated condition consists ofβmatrix with primaryαphase distributing in it.Fine acicular secondaryαphase is precipitated during the subsequent aging process of these two kinds of microstructure,and the length and width of secondaryαphase increase with the increase of aging temperature.For theβsolution treated+aged sample,however,the size of secondaryαphase nearβgrain boundary is larger than that insideβgrain.Theαphases are first precipitated atβgrain boundary during slow cooling from 910℃,and the lamellarαcolonies subsequently are formed and grown by taking grain boundaryαphases as the nucleation nucleus,some fine secondaryαphases are precipitated betweenαlaths during subsequent aging process at 520℃.The electron backscatter diffraction(EBSD)analysis results show that,during the slow cooling process,only oneαvariant is precipitated at the grain boundary with theβgrains on both sides having parallel{110}planes,which theαvariant keeps Burgers orientation relationship with both grains.And the lamellarαphase can grow towards both sides of the grain boundary by taking theαvariant as the nucleation nucleus.Manyαvariants may form at the grain boundary where theβgrains on both sides have no parallel{110}planes,eachαvariant keeps Burgers orientation relationship only with one of the twoβgrains,and lamellarαphase is formed by taking this variant as its nucleation nucleus and growing to the side of theβgrain with its Burgers orientation.
作者
杨康江
金头男
赵永庆
舒群
Yang Kangjiang;Jin Tounan;Zhao Yongqing;Shu Qun(School of Materials Science and Engineering,Beijing University of Technology,Beijing 100124,China;Northwest Institute for Nonferrous Metal Research,Xi’an Shaanxi 710016,China)
出处
《金属热处理》
CAS
CSCD
北大核心
2019年第12期13-18,共6页
Heat Treatment of Metals
关键词
Ti-5321合金
热处理
Α相
析出
电子背散射衍射
Ti-5321 alloy
heat treatment
αphase
precipitation
electron backscattering diffraction(EBSD)
