冷却方式对BT25y钛合金显微组织和拉伸性能的影响  

Influence of Cooling Method on Microstructure and Tensile Properties of BT25y Titanium Alloy

作　　者：张潇[1] 陈立佳[1] 赵子博[2] 刘建荣[2] 王清江[2] 

机构地区：[1]沈阳工业大学,辽宁沈阳110870 [2]中国科学院金属研究所,辽宁沈阳110016

出　　处：《稀有金属材料与工程》2018年第1期321-325,共5页Rare Metal Materials and Engineering

摘　　要：采用金相(OM)、扫描电镜(SEM)、X射线衍射(XRD)、透射电镜(TEM)等技术研究了固溶处理后的冷却方式对BT25y钛合金显微组织和拉伸性能的影响。结果表明,950℃固溶处理后空冷得到的组织由α相与β转变组织组成,水淬与油淬组织主要由等轴α相、针状α'相与羽毛状α''马氏体相组成;与油淬相比,水淬得到的α''相的晶格常数a值减小,b值增大。经时效处理后,固溶后空冷组织的相组成没有变化,油淬与水淬组织中的马氏体相分解为稳定的α相与β相。室温拉伸结果表明:相对于空冷组织,油淬与水淬组织的屈服强度与抗拉强度明显升高,而延伸率明显低于空冷组织,该现象与原始β晶粒内析出的次生α相的弥散程度及界面密度有关。The effect of cooling method on microstructure and tensile properties of BT25y titanium alloy were studied using OM, SEM, XRD, and TEM. The results indicate that the microstructure of the air-cooled specimen consists of a and ,8 transformed phase, while in oil- and water-quenched microstructure, a, a＇ and a＂ martensite phase are found. Lattice parameters of a＂ phase obtained by XRD analysis show that a is shorter, b is longer in water-quenched microstructure than in oil-quenched one. After aging treatment at 550 ℃/6 h followed by air cooling, the phase component is the same with its unaged counterpart in air-cooled condition; martensite phase is decomposed into stable a and fl phase in oil- and water-quenched conditions. Room temperature tensile properties after aging treatment were tested. Compared with the air-cooled sample, tensile and yield strength of the sample after oil and water quenching are much higher, accompanied with much lower elongation. The phenomenon is thought to be related to the shape and size of secondary a phase.

关 键 词：BT25Y钛合金 冷却方式 相组成 拉伸性能 

分 类 号：TG166.5[金属学及工艺—热处理]