GH4169材料广泛应用于航空航天、核电和石油化工等领域，传统加工方式难以满足复杂结构零件的高性能及快速制造需求，选区激光熔化(SLM)提供了一种新的制造方法。SLM成型过程中的高温度梯度和高冷却速率与传统制造方法显著不同，有必要对热处理后SLM成型GH4169高温合金的微观组织演变和力学性能进行研究。本工作采用SLM技术制备GH4169高温合金，分析讨论了打印态以及直接时效和固溶时效热处理后GH4169高温合金的微观组织和力学性能，通过不同热处理状态合金的相结构分析，建立显微组织与力学性能的构效关系。结果表明，打印态合金组织主要以γ基体和Laves相为主；直接时效后基体内部有γ′/γ″相析出；固溶时效后Laves相发生溶解，有大量尺寸小于1 μm的δ相析出，并均匀分布在晶内和晶界，基体内部γ′/γ″相分布更加均匀。SLM成型GH4169高温合金的显微硬度为311 HV，室温抗拉强度为961 MPa，屈服强度为649 MPa。热处理后，合金的硬度和强度均显著提升，其中固溶时效态合金的显微硬度为518 HV，室温抗拉强度为1393 MPa，屈服强度为1233 MPa，高于对应的锻件材料。550、650和750 ℃高温拉伸性能结果表明，热处理态样品在650 ℃的高温强度满足相应锻件标准。由于SLM成型过程中的温度梯度大、冷却速率高，制备的GH4169试样具有精细的胞状和柱状枝晶结构，晶粒尺寸小，位错密度高，热处理后有γ′/γ″强化相析出，由细晶强化、位错强化和沉淀强化作用机制共同提高了GH4169高温合金的力学性能。

GH4169 materials are widely used in aerospace, nuclear power, petrochemical, and other industries. However, conventional processing methods fail to meet the demands of high-performance and rapid manufacturing for complex structural parts. Therefore, selective laser melting (SLM) has been adopted as a new rapid manufacturing technology to address these demands. The high-temperature gradient and rapid cooling rate generated during SLM result in a considerably different microstructure in the GH4169 alloy compared with those produced via conventional melting and forging methods. Consequently, heat treatment is an essential post-processing step to enhance the precipitation strengthening of the GH4169 superalloy. Thus, it is critical to examine the microstructure and mechanical properties of the SLM-formed GH4169 alloy after heat treatment. This study focuses on fabricating the GH4169 alloy using SLM technology and investigates the microstructure and mechanical properties of the as-built, directly aged, and solution-aged GH4169 alloy specimens. Results reveal that the as-built structures primarily comprise a γ matrix and Laves phase. After direct aging, the γ′/γ″ phase precipitates within the matrix. After solution aging, the Laves phase completely dissolves. Moreover, the δ phase precipitates with a size of < 1 μm become abundant and uniformly distributed within grains and grain boundaries. Simultaneously, the γ′/γ″ phase precipitate within the matrix, resulting in a more homogeneous distribution. The microhardness, tensile strength, and yield strength at room temperature (25 ^oC) of the SLM GH4169 alloy are 311 HV, 961 MPa, and 649 MPa, respectively. Heat treatment substantially improves the hardness and strength of the material. In the solution-aged state, the microhardness reaches 518 HV, with a tensile strength of 1393 MPa and a yield strength of 1233 MPa at room temperature. Notably, these static mechanical properties surpass those of the corresponding forged materials. The tensile properties at 550, 650, and 750 ^oC indicate that the elevated strength of the heat-treated samples at 650 ^oC complies with relevant forging standards. Owing to the substantial temperature gradient and rapid cooling rate during the SLM forming process, the GH4169 sample exhibits a refined cellular and columnar dendritic structure, small grain size, and high dislocation density. Subsequent heat treatment induces γ′/γ″ phase precipitation, enhancing the mechanical properties of the GH4169 alloy through fine crystal strengthening, dislocation strengthening, and precipitation strengthening.