(1.中南大学粉末冶金国家重点实验室，长沙 410083；
2.中南大学粉末冶金研究院，长沙 410083；
3.中南大学材料科学与工程学院，长沙410083)
摘 要: 采用差热分析技术，研究样品质量和升温速率对FGH96合金差热曲线的影响。以FGH96为代表，探索采用差热曲线分析方法准确测量粉末冶金高温合金相变温度的最佳升温速率和样品质量。分析和对比差热曲线不同方法判定的γ′相完全溶解温度、固相线温度及液相线温度。改进了固相线判定方法，并在此基础上确定了FGH96合金中主要相变温度的最优判定方法。实验测定了FGH96合金热等静压、热挤压和热处理状态的相变温度。结果表明：FGH96合金在不同状态下的相变温度基本相同。同时，确定了高温合金差热分析的两个重要实验参数，提出可统一应用于高温合金差热曲线分析相变温度的判定方法。
关键字: FGH96；粉末冶金高温合金；差热分析；相变温度；样品质量；升温速率；热力学计算
（1.State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China;
2. Research Institute of Powder Metallurgy, Central South University, Changsha 410083, China;
3.School of Materials Science and Engineering, Central South University, Changsha 410083, China）
Abstract:The effects of sample mass and heating rate on differential thermal analysis (DTA) curves were investigated. Available methods for determining gamma prime(γ′)solvus, solidus and liquidus were analyzed and compared separately. This study improves methods for determining solidus and identifies optimal methods for measuring temperature of γ′solvus, solidus and liquidus. Transformation temperatures of FGH96 samples prepared by hot isostatic pressing(HIP), hot extrusion(HEX) and heat treatment(HT) were tested. DTA curves do not show significant differences.Appropriate sample mass and heating rate are obtained, and auniversalapplicable analysis method of DTA curves for dermining phase transformation temperatures of powder metallurgy superalloy is proposed.
Key words: FGH96; powder metallurgy superalloy; differential thermal analysis; transformation temperature; sample mass; heating rate; thermodynamic calculation
