激光辅助增材制造CoCrNi中熵合金的纵向力学性能研究

Research on Longitudinal Mechanical PropertiesofCoCrNi Medium Entropy Alloy Fabricated by Laser Aided Additive Manufactured

针对钴铬镍(CoCrNi)增材制造过程中,因热传导具有方向性,且受层间结合强度和材料显微结构影响,导致CoCrNi的纵向(平行于材料沉积方向)力学性能(屈服强度、抗拉强度、延伸率)较差的问题,采用激光辅助增材制造方法制备CoCrNi中熵合金。实验结果发现:随着打印工件沉积高度增加,散热性变差,出现较大的外延晶,且产生热裂纹;制备的CoCrNi纵向力学性能明显低于文献[9]的横向力学性能,但保持了相对较好的强度和韧性。

In view of the poor longitudinal(parallel to the material deposition direction)mechanical properties(yield strength,tensile strength and elongation)of CoCrNi due to the directionality of heat conduction and the influence of interlayer bonding strength and material microstructure during the manufacturing of CoCrNi additive,a laser aided additive manufacturing method was used to prepare CoCrNi medium entropy alloy.The experimental results show that with the increase of the deposition height of the printing workpiece,the heat dissipation becomes poor,large epitaxial crystals appear,and thermal cracks occur;The longitudinal mechanical properties of the prepared CoCrNi are significantly lower than the transverse mechanical properties of reference[9],but maintain relatively good strength and toughness.