Selective Laser Melting of Carbon-Free Mar-M509 Co-Based Superalloy:Microstructure,Micro-Cracks,and Mechanical Anisotropy  

作　　者：Xiaodong Wang Chaoyue Chen Ruixin Zhao Longtao Liu Sansan Shuai Tao Hu Jiang Wang Zhongming Ren 

机构地区：[1]State Key Laboratory of Advanced Special Steels,School of Materials Science and Engineering,Shanghai University,Shanghai 200444.China

出　　处：《Acta Metallurgica Sinica(English Letters)》2022年第3期501-516,共16页金属学报（英文版）

基　　金：financially supported by the National Key Research and Development Program of China(No.2019YFA0705300);the Chinese National Science and Technology Major Project“Aeroengine and Gas Turbine”(No.2017-VII0008-0102);the Shanghai Science and Technology Committee(No.19DZ1100704);Shanghai Shuguang Program(No.20SG42);Shanghai Sailing Program(No.19YF1415900);the National Natural Science Foundation of China(No.52001191);the Shanghai Rising-Star Program(No.20QA1403800)。

摘　　要：In this work,the microstructural evolution,micro-crack formation,and mechanical anisotropy of the selective laser melted(SLM)carbon-free Mar-M509 Co-based superalloy were systematically studied under different linear energy densities(LED).Observation shows that the SLM Mar-M509 superalloy possesses a fully dense structure,whereas some microcracks exist along the building direction.The electron backscatter diffraction results reveal that dominant columnar grains tend to elongate along the building direction parallel to the XZ plane.Meanwhile,both a<001>near fiber texture and a{100}<001>near sheet texture are observed in different specimens.For the specimen with fiber texture,a high misorientation angle exists among different columnar grains,which aggravated the generation of micro-cracks under thermal stress.Higher LED results in higher micro-crack density in the SLM specimen due to higher thermal stress.Mar-M509 specimen fabricated under lower LED exhibits higher tensile strength due to more significant grain refinement.More prominent anisotropy of tensile performance was found in the high LED specimen,which can be attributed to the higher density of micro-cracks and crystallographic texture.Furthermore,the SLM Mar-M509 superalloy exhibits better mechanical properties than the traditional cast technique.In summary,this work can contribute to the development and the future application of SLM-fabricated Co-based superalloy.

关 键 词：Selective laser melting Mar-M509 Co-based superalloy Linear energy density ANISOTROPY Mechanical properties 

分 类 号：TG132.3[一般工业技术—材料科学与工程]