激光增材制造近β钛合金显微组织与力学性能研究  

Study on Microstructure and Mechanical Properties of Laser Metal Deposition NearβTitanium Alloy

作　　者：李海涛[1] 齐敏 陈冬梅[1] 黄森森[2] 王倩 马英杰[2] 雷家峰[2] LI Haitao;QI Min;CHEN Dongmei;HUANG Sensen;WANG Qian;MA Yingjie;LEI Jiafeng(Avic Shenyang Aircraft Design&Research institute,Shenyang 11035,China;Institute of Metal Research,Chinese Academy of Sciences,Shenyang 11016,China)

机构地区：[1]中航工业沈阳飞机设计研究所,辽宁沈阳110035 [2]中国科学院金属研究所,辽宁沈阳110016

出　　处：《材料开发与应用》2024年第1期30-37,共8页Development and Application of Materials

基　　金：国家重点研发计划(2021YFC2801801)。

摘　　要：研究了激光沉积打印Ti55511钛合金的显微组织和室温拉伸性能,表征了打印态、热处理态Ti55511合金的晶粒形态及晶体学织构,分析了不同退火热处理温度对激光增材制造钛合金强塑性的影响。结果表明,原始打印态Ti55511钛合金由粗大的β晶粒组成,并且β晶粒以柱状晶和等轴晶两种类型的晶粒交替生长,呈现竹节状形态。在打印态Ti55511组织中,β基体析出的α片层提供了大量的界面,有效阻碍了位错运动,使合金具有高强度和低塑性。580℃退火热处理后,合金的屈服强度、抗拉强度变化不明显,伸长率有一定的提升。进一步提高退火温度至620℃后,合金的屈服强度、抗拉强度降低,但强度值依然大于1000 MPa,同时伸长率大幅提升。因此,可通过退火热处理调控α晶粒的尺寸和体积分数,以提高合金的强塑性匹配。当应力平行于Z方向时,样品的屈服强度、抗拉强度略低于垂直于Z方向的,而伸长率显著高于应力垂直于Z方向的。The microstructure and tensile properties at room temperature of the laser additive manufacturing Ti55511 titanium alloy are studied,the grain morphologies and crystallographic texture of the as-deposited and heat treated Ti55511 titanium alloy are characterized,and the effects of different annealing temperatures on plasticity of the laser additive manufactured Ti55511 titanium alloy are analyzed.The results indicate that the as-deposited Ti55511 titanium alloy consists of coarseβgrains,and theβgrains grow alternately in the form of columnar and equiaxed grains,presenting a bamboo-like morphology.In the as-deposited Ti55511 titanium alloy,theαlamellae precipitated from theβmatrix provides a large number of interfaces,effectively hindering the movement of dislocations,and allows the alloy having high strength and low plasticity.The yield strength and tensile strength of the alloy annealed at 580℃does not show significant changes,and the elongation increases to a certain extent.When the annealing temperature increases to 620℃,the yield strength and tensile strength of the alloy reduce,still greater than 1000 MPa,and the elongation significantly increases.Therefore,the size and volume fraction of theαgrains can be regulated through the annealing heat treatment to improve the strength and toughness balance of the alloy.When the stress is parallel to the Z deposition direction,the yield strength and tensile strength of the specimen are slightly lower than those of the specimen whose stress is perpendicular to the Z deposition direction,and the elongation is significantly higher than that of the specimen whose stress is perpendicular to the Z deposition direction.

关 键 词：Ti55511钛合金 增材制造 显微组织 力学性能 

分 类 号：TG146.23[一般工业技术—材料科学与工程]