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 Near β Titanium Alloy
李海涛 1齐敏 2陈冬梅 1黄森森 2王倩 2马英杰 2雷家峰2
作者信息
- 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
- 折叠
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1 000 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.
Abstract
The microstructure and tensile properties at room temperature of the laser additive manufacturing Ti55511 titanium al-loy 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 ti-tanium alloy are analyzed.The results indicate that the as-deposited Ti55511 titanium alloy consists of coarse β grains,and theβ grains grow alternately in the form of columnar and equiaxed grains,presenting a bamboo-like morphology.In the as-deposi-ted Ti55511 titanium alloy,the α lamellae precipitated from the β matrix provides a large number of interfaces,effectively hin-dering 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 1 000 MPa,and the elongation significantly increases.Therefore,the size and volume fraction of the α grains can be regu-lated 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Key words
Ti55511 titanium alloy/additive manufacturing/microstructure/mechanical property引用本文复制引用
基金项目
国家重点研发计划(2021YFC2801801)
出版年
2024
NETL
NSTL
万方数据