摘要
以Ni Cr Fe Al预合金粉为原料,采用选区激光熔化技术制备Ni Cr Fe Al合金。通过光学显微镜对样品孔隙进行分析,从而优化扫描工艺参数,采用扫描电子显微镜对合金组织形貌进行表征,并使用EBSD进行缺陷分析,用UTM 5105型电子万能实验机测试合金力学性能。结果表明:选区激光熔化的最优工艺参数为扫描功率240 W、扫描速度1 000 mm/s,扫描间距0.12 mm,层厚0.03 mm。最优工艺参数下合金的抗拉强度为535 MPa,伸长率为5.8%。合金中存在固态裂纹,水平和垂直截面上均表现为沿晶断裂,裂纹存在于取向差较大的相邻晶粒之间。合金水平截面上的平均晶粒尺寸为35μm,低角度晶界占37.0%;竖直截面上的平均晶粒尺寸为56μm,低角度晶界占41.0%。
NiCrFeAl alloy was prepared by selective laser melting(SLM) using Ni Cr Fe Al prealloy powders as raw material. The optimizing of SLM processing parameters was carried out through optical analyzing on pores. Scanning electron microscope was ultilized for microstructure characterization of the alloy, and defects were analyzed by EBSD.The mechanical properties tests were carried out on UTM 5105 electronic universal testing machine. Results show that the optimal processing parameters of NiCrFeAl alloy fabrication are as follows: laser power of 240 W, scanning speed of 1 000 mm/s, hatching spacing of 0.12 mm and layer thickness of 0.03 mm. The corresponding tensile strength and elongation are 535 MPa and 5.8% respectively. There are solid cracks distributed between adjacent grains with large misorientation, showed intergranular fracture on horizontal and vertical cross sections. The average grain size on the horizontal cross section of the alloy is 35 μm, and the low angle grain boundaries accounts for 37.0%. The average grain size on the vertical section is 56 μm, and the low angle grain boundaries accounts for 41.0%.
作者
徐瑞锋
耿赵文
陈超
张家琪
李丹
倪莽
周科朝
XU Ruifeng;GENG Zhaowen;CHEN Chao;ZHANG Jiaqi;LI Dan;NI Mang;ZHOU Kechao(State Key Laboratory of Powder Metallurgy,Central South University,Changsha 410083,China)
出处
《粉末冶金材料科学与工程》
2022年第6期586-594,共9页
Materials Science and Engineering of Powder Metallurgy
基金
国家自然科学基金资助项目(52271046)
湖南省自然科学基金优秀青年项目(2022JJ20061)。
关键词
增材制造
选区激光熔化
镍基合金
力学性能
显微组织
additive manufacturing
selective laser melting
nickel-based alloys
mechanical property
microstructure
