Laser metal deposition (LMD) shows outstanding advantages in manufacturing complex parts. In practice, some formed parts usually require directional properties in order to obtain better service performance in its use. This study has comprehensively analyzed the microstructure, texture and porosity of CrCoNi medium-entropy alloy thin-walled parts manufactured by LMD process, as well as the effect of these factors on its mechanical anisotropy. The results show that the yield strength in the building direction is slightly higher than the scanning direction and the uniform elongation is about 1.5 times. Meanwhile, the fracture morphology and microcrack characteristics of the tensile samples in these two directions have also been studied. The results reveal that cross-slip microcracks and microcrack deflection appeared in the scanning direction and building direction, respectively. In addition, it has also been made clear that initial dislocations can contribute to the yield strength of thin-walled samples. The work provides guidance for the design freedom and scanning strategy of engineering parts with directional performance by the LMD process.

激光金属沉积（LMD）在制造复杂零件方面显示出突出的优势。实际上，某些成型零件通常需要方向性，以便在使用中获得更好的服务性能。本研究综合分析了LMD工艺制备的CrCoNi中熵合金薄壁零件的组织，织构和孔隙率，以及这些因素对其力学各向异性的影响。结果表明，建筑方向的屈服强度略高于扫描方向，均匀伸长率约为1.5倍。同时，还研究了这两个方向上拉伸试样的断裂形态和微裂纹特征。结果表明，横向滑动微裂纹和微裂纹偏转分别出现在扫描方向和构建方向。另外，还已经清楚，初始位错可有助于薄壁样品的屈服强度。这项工作为LMD流程具有定向性能的工程零件的设计自由度和扫描策略提供了指导。