摘要
采用激光三维(3D)打印技术制备了TC4厚壁件,利用光学显微镜、扫描电子显微镜(SEM)、X射线衍射仪(XRD)及电子万能试验机等研究了正火温度对激光3D打印TC4钛合金显微组织、相组成、室温拉伸性能的影响规律。结果表明:当在α-Ti相单相区内正火处理时,α-Ti相再结晶生长,长、宽均增加;组织主要由α-Ti相组成,含有少量(或微量)β-Ti相;合金的室温拉伸性能一般。当在α+β两相区内正火处理时,沉积态下的细长状初生α-Ti相由于β-Ti相析出而被截断,变成短棒状初生α-Ti相;β-Ti相不仅与次生α-Ti相共存于短棒状初生α-Ti相之间,还会在短棒状初生α-Ti相内部呈网状析出。经990℃/2 h/AC处理后,合金的室温抗拉强度为960 MPa,屈服强度为835 MPa,断后伸长率为17%,达到了锻件国标要求。拉伸试样断口上均布满韧窝,均为延性断裂。
In this study, TC4 titanium alloy bulk specimens are prepared using the laser three-dimensional(3D)printing technology. The effect of normalizing temperature on the laser 3D-printed TC4 titanium alloy microstructure, phase composition, and tensile properties at room temperature is studied via an optical microscope, scanning electron microscopy(SEM), X-ray diffractometer(XRD), and electronic universal testing machine. Experimental results reveal that the α-Ti phase recrystallizes and the length and width of the α-Ti phase increase after being normalized at the α-Ti phase zone. The microstructures mainly comprise α-Ti phase and a small amount(or trace amount) of the β-Ti phase. The tensile property at room temperature is general. After being normalized at the α+β phase zone, the slender primary α-Ti phase in the as-deposited state thrusts each other because of the β-Ti phase precipitation, transforming into a short rod-shaped primary α-Ti phase. The β-Ti phase not only coexists with the secondary α-Ti phase between the short rod-shaped primary α-Ti phases, but also precipitates and is distributed as networks inside the short rod-shaped primary α-Ti phase. After 990 ℃/2 h/AC treatment, the room-temperature tensile strength, yield strength, and elongation are 960 MPa, 835 MPa, and 17%, which satisfy the national standard for forging. The fracture morphology of the tensile specimens is covered with dimples, all of which are ductile fractures.
作者
马瑞鑫
徐国建
刘占起
高飞
王蔚
苏允海
Ma Ruixin;Xu Guojian;Liu Zhanqi;Gao Fei;Wang Wei;Su Yunhai(School of Materials Science and Engineering , Shenyang University of Technology, Shenyang, Liaoning 110870, China;School of Mechanical Engineering , Shenyang University of Technology, Shenyang , Liaoning 110870, China)
出处
《中国激光》
EI
CAS
CSCD
北大核心
2019年第7期117-124,共8页
Chinese Journal of Lasers
基金
国家重点研发计划(2017YFB1103600)
关键词
激光技术
激光三维打印
TC4钛合金
正火温度
显微组织
力学性能
laser technique
laser three-dimensional printing
TC4 titanium alloy
normalizing temperature
microstructure
mechanical properties
