基于自主研制的金属富氧燃烧实验设备，在O₂浓度为99.5%、压强为3.5~25 MPa条件下，对GH4061合金进行了燃烧实验，使用高速相机、SEM、EDS和XRD对合金燃烧过程以及燃烧后的试棒进行观察分析，研究了高压富氧条件下GH4061合金的燃烧过程，并分析了其燃烧机理。结果表明，随着O₂压强的提高，试棒燃烧长度增大，同时燃烧速率加快。根据ASTM-G124标准，GH4061合金在99.5%纯O₂室温点燃条件下，燃烧阈值约为5 MPa。合金的燃烧区域自上而下可以分为过渡区、熔化区、燃烧前沿和氧化物区。燃烧过程中，燃烧热较高的元素优先燃烧，液态金属与O₂接触发生反应形成熔融的氧化物，其中密度较低的氧化物会上浮至熔化区，并在上浮过程中凝固形成尺寸较小的富Al/Ti氧化物和尺寸较大、具有枝晶形貌的混合氧化物。基于热力学理论，分析了O₂压强对合金燃烧行为的影响。

Liquid oxygen (LOX)/kerosene rocket engines are the main power system of heavy launch vehicles around the globe, and the turbine materials are usually exposed to elevated temperatures, high pressure, and oxygen-enriched environment in gas generators. Metal combustion may occur under these working conditions. GH4061 is a newly developed Ni-based superalloy that is used in turbine materials because of its excellent mechanical properties. However, its combustion resistance property has rarely been studied. Recently, several studies on metal combustion have been conducted, but they mainly focus on exploring the rules of metal combustion. Furthermore, the domestically promoted ignition-combustion (PIC) experiment equipment only supports the test under 2 MPa pressure, which has significantly limited the study of metal combustion at higher pressure. Therefore, the analysis of the metal combustion mechanism remains incomplete. In this study, the 3.5-25 MPa high pressure and oxygen-enriched combustion experiments of GH4061 alloy were performed on the basis of independently-developed PIC equipment with a maximum pressure of 25 MPa. A high-speed camera was used to observe and record the combustion process. The postcombustion microstructure was characterized using SEM and EDS, and the combustion product was identified using XRD. The length and rate of burning increase as the oxygen pressure increases. The critical burning pressure of GH4061 under 99.5% oxygen (when igniting at 25^oC) is about 5 MPa, according to ASTM-G124. After testing, the transition zone, melting zone, ignition interface, and oxide zone in the samples were characterized. The burning process is due to elements with a higher heat of combustion. During combustion, lower-density molten oxides float up to the melting zone. After testing, small O/Al/Ti-rich particles and large complex oxide particles with dendritic morphology were observed in the melting zone. The effect of oxygen pressure was analyzed using thermodynamics.