Research Progress of Selective Laser Melting to Prepare Continuously Graded Alloys

Baicheng Zhang*，Yaojie Wen, Xuanhui Qu

Beijing advanced innovation center for materials genome engineering

ABSTRACT: Recently, the development of additive manufacturing technology has attracted the attention of the whole society. According to McKinsey's 2019 report, additive manufacturing technology is ranked first among the ten most promising technologies. Metal additive manufacturing occupies the highest proportion in additive manufacturing technology, but the powder, wire traditional casting and forging grades used in metal additive manufacturing, its element combination, and precipitation phase design are not completely suitable for additive manufacturing. In the rapid melting and rapid cooling process. Therefore, in the preparation process of laser melting, direct metal deposition, and electron beam melting of traditional grade materials, many problems will occur, leading to cracks, defects, and material performance degradation. Therefore, the optimization of additive manufacturing material system is imminent, and a high-throughput preparation platform based on high-energy beam processing is urgently needed. Our research group successfully prepared continuous gradient alloys by reforming the selective laser melting system. On this basis, the composition of high-entropy alloys and nickel-based superalloys was optimized. A defect-free continuous gradient alloy was successfully prepared, and the printing gradient alloy was characterized by high-throughput characterization methods. At the same time, the microstructure, phase composition, element distribution and mechanical properties were also analyzed. In this experiment, the Fe, Ni, Co, Ti-based continuous gradient alloy was prepared by laser melting in the selected area, and the element distribution, phase composition change law, and comprehensive microstructure-mechanical properties were analyzed, and the continuous gradient alloy was obtained The alloying mechanism and composition optimization results. This work will provide the experimental platform and theoretical basis for the following research of the material development.

Keywords: compositionally graded material; selective laser melting