激光选区熔化制备纯钽高温拉伸性能研究
Study on High Temperature Tensile Properties of Pure Tantalum Prepared by Selective Laser Melting
闫超 1吕绪明 1贾子朝1
作者信息
- 1. 粒子输运与富集技术全国重点实验室,天津 300180;核工业理化工程研究院,天津 300180
- 折叠
摘要
对采用激光选区熔化(SLM)技术横、纵向成形的纯钽试样开展力学性能研究.采用SEM、XRD对所制备钽试样的微观组织及物相组成进行研究,并采用显微硬度计、万能试验机对其硬度及室温和高温拉伸性能进行研究.结果表明,SLM横向成形钽试样的组织为等轴晶粒;SLM纵向成形钽试样的组织为拉长晶粒.SLM钽试样的物相组织为BCC-Ta,Ta含量大于99.995％,平均致密度为99.87％,平均显微硬度为191 HV.在室温条件下,SLM钽试样展现出优异的强度和延展性.随着拉伸温度的升高,SLM钽试样的强度和延展性均下降,600 ℃下由于动态应变时效其延展性最差.SLM钽试样的室温断口形貌为韧性断裂特征,随着拉伸温度的升高,其断口解理特征越来越明显,在1 200 ℃下断口出现严重的氧化腐蚀,呈沿晶氧化腐蚀开裂的特征.在室温至1 200 ℃范围内,SLM纵向成形钽试样的拉伸性能略优于SLM横向成形钽试样.
Abstract
Mechanical properties of pure tantalum samples transversely or longitudinally formed by using selective laser melting(SLM)were investigated.The microstructure and phase composition of the prepared tantalum samples were studied by SEM and XRD,and their hardness and tensile properties at room tem-perature and high temperature were studied using microhardness tester and universal testing machine.The results show that the tantalum samples transversely formed by SLM exhibit a microstructure of equiaxed grains while the tantalum samples longitudinally formed by SLM show a miscrostructure of elongated grains.The phase composition of the SLM tantalum samples is BCC-Ta,with a Ta content over 99.995％.Meanwhile,the average compactness of the samples reaches 99.87％and the average microhardness is 191 HV.The SLM tantalum samples exhibit excellent strength and ductility at room temperature.How-ever,as the tensile temperature increases,their strength and ductility decrease,with the ductility reaching its worst at 600 ℃ due to dynamic strain aging.The fracture morphology at room temperature of the SLM tantalum samples is ductile fracture,and the cleavage characteristics of the fracture become more obvious as the tensile temperature increases.At 1 200 ℃,the fracture surface exhibits severe oxidation corrosion,presenting characteristics of intergranular oxidation corrosion cracking.Within the temperature range from room temperature to 1 200 ℃,the tensile properties of the tantalum samples longitudinally formed by SLM are slightly better than those of the tantalum samples transversely formed by SLM.
关键词
钽/激光选区熔化/高温拉伸/硬度/力学性能/断口形貌Key words
tantalum/selective laser melting/high temperature tension/hardness/mechanical property/frac-ture morphology引用本文复制引用
基金项目
中国原子能燎原计划项目(YZNLY-22631)
出版年
2024
NETL
NSTL
万方数据