基于近年来对镍基高温合金部件性能可靠性需求的提升，以激光选区熔化成形制备GH4099高温合金为 研究对象，探究其微观组织和力学性能的各向异性。利用OM、SEM、EBSD等分析测试方法对沉积态GH4099合金微观 组织进行表征，并在室温下沿水平和沉积方向进行拉伸试验，探究微观组织与力学性能之间的关系。 实验结果表明，沉 积态样品由沿沉积方向外延生长的柱状晶构成，有少量小尺寸碳化物存在，但无第二相析出。水平方向的屈服强度和断 裂强度均大于沉积方向，但伸长率较小，两个方向的断口都表现出典型的穿晶断裂形貌。

In response to the increasing demand for reliable performance of nickel-based superalloy components in recent years, this study focused on a GH4099 superalloy fabricated via selective laser melting to investigate the anisotropy in its microstructure and mechanical properties. The microstructure of the as-deposited GH4099 alloy was characterized via OM, SEM and EBSD, and tensile tests were conducted at room temperature in both the horizontal and deposition directions to investigate the relationships between the microstructure and mechanical properties. The experiment reveals that the as-deposited sample consists of columnar crystals that epitaxially grow along the deposition direction, with a small amount of small carbides present but no second phase precipitation. The yield strength and fracture strength in the horizontal direction are both greater than those in the deposition direction, but the elongation is lower. The fracture surfaces in both directions exhibit typical transgranular fracture morphologies.