GH4169合金作为航空航天发动机关键热端部件的核心材料，在高温富氧服役环境中存在金属燃烧的风险。本工作基于自主研制的金属材料富氧燃烧实验设备，研究了热处理对选区激光熔化制备的GH4169合金阻燃性能的影响。结果表明，沉积态样品具有典型的鱼鳞状熔池形貌，在枝晶间和晶界处析出大量低熔点Laves相。合金经过980 ℃固溶处理后，Laves相大量溶解，并在晶界和枝晶间析出针状和短棒状δ-Ni₃Nb相。当固溶温度提高至1080 ℃时，析出相数量显著降低，晶内为少量纳米级颗粒状Laves相，晶界析出块状碳化物相。富氧燃烧实验结果表明，沉积态样品的阻燃性能最差，1080 ℃热处理样品的阻燃性能最优，而980 ℃热处理样品的性能居中。燃烧区组织分析发现，GH4169合金的阻燃性能与析出相种类和数量有关。Laves相富含高燃烧热的Nb元素，且熔点较低，在燃烧时会优先熔化并参与燃烧，从而加速燃烧反应进程，这使得沉积态样品的阻燃性能最差；晶界作为O元素快速扩散通道，是易发生燃烧的位置，由于980 ℃热处理样品的晶界处析出了大量富含Nb元素的δ相，造成980 ℃热处理样品的阻燃性能较1080 ℃热处理样品有所下降。因此，消除低熔点相和控制晶界析出相类型是提升GH4169合金阻燃性能的关键。

With the advancement of high-thrust liquid rocket engine toward higher chamber pressure and specific impulse, the turbine pump system of the gas generator is being increasingly exposed to extreme high-temperature and high-pressure oxygen-enriched environments. This exacerbates the risk of metal-oxidation combustion failure of superalloy components. The production of high-performance and complex-structured superalloy parts via selective laser melting technology has emerged as a key research area in the manufacture of critical aerospace components. Therefore, the investigation of the oxygen-enriched combustion mechanism of high-temperature alloy materials fabricated using the selective laser melting technology is of great practical significance. This study investigated the effect of heat treatment on the flame retardant property of GH4169 alloy produced via selective laser melting using self-developed experimental equipment designed for oxygen-enriched combustion testing of metal materials. A high-speed camera was used to observe and record the combustion process. The microstructure and combustion morphology of the alloy were analyzed using OM, SEM, and EDS. The as-deposited sample exhibited a typical fish-scale molten pool morphology, with numerous low-melting-point Laves phases precipitating in the interdendritic regions and grain boundaries. Following heat treatment at 980 ^oC, most Laves phases dissolved, and needle-like and short rod-like δ-Ni₃Nb phases precipitated at the grain boundaries and in the interdendritic regions. Upon increasing the solution temperature to 1080 ^oC, the volume fraction of precipitated phases was significantly reduced. Consequently, only a small number of nano-sized Laves particles were formed within the grains and a certain amount of blocky carbides were located at the grain boundaries. Combustion resistance testing revealed that the as-deposited sample exhibited the poorest resistance, whereas samples heat-treated at 1080 ^oC demonstrated the highest resistance. Further, microstructural analysis confirmed that the combustion behavior was closely related to the type and volume fraction of the precipitates within the matrix. Laves phases with high Nb content melted early in the combustion, thereby accelerating the reaction owing to the high combustion heat of Nb. The δ phases formed after heat treatment at 980 ^oC also promoted combustion. Thus, these findings suggest that eliminating the low-melting-point phases and controlling the types of precipitated phases are key strategies for enhancing the flame retardant properties of GH4169 alloy.