Yang, Jiaoxi, Zhu, Qing, Wang, Zekang, Xiong, Falin, Li, Qiang, Yang, Feng, Li, Ran, Ge, Xueyuan, and Wang, Miaohui
Metallurgical defects significantly affect the performance of materials fabricated by selective laser melting (SLM), becoming a bottleneck problem in the application of laser 3D printing technology. To investigate the effect of metallurgical defects on the magnetic properties of SLM NiFeMo permalloy. An in-depth characterization of the microstructure and phase composition of SLM-fabricated NiFeMo permalloy samples were carried out. Soft magnetic DC B H hysteresis loop tester was used to assess the magnetic properties. Defect voxel data of as-built samples were obtained using X-ray microcomputed tomography (XCT). The results show that the micro-defects of SLM NiFeMo alloy are mainly composed of lack of fusion, pores, etc., and the phase composition of NiFeMo is mainly γ- (Ni, Fe) solid solution. With the increase of laser volume energy density, the B s and μ m of the material increase, while the H c and P u decreases. The equivalent diameter of the defects shows a positive correlation with the coercivity (H c) and a negative correlation with the saturation magnetic induction (B s) of NiFeMo permalloy. • The microstructural features, the evolution of defect size and morphology were analyzed and described in detail. • Defect data information in SLM-fabricated permalloy was extracted and quantified using XCT. • Permalloy samples with relatively good magnetic properties were obtained by adjusting the process conditions. • Constructed and validated an approximate relational model describing the correlation of defects and magnetic properties. [ABSTRACT FROM AUTHOR]