Abstract GTD222 is an important structural alloy that is applied as a high-temperature hot-end part. In this work, the effect of a high-temperature (800–950 °C) aging treatment on the microstructural evolution and mechanical performance of a GTD222 superalloy fabricated with selective laser melting (SLM) processed is investigated. Precipitates of γ′-Ni3(Al, Ti) with different morphologies and sizes are obtained after different high-temperature aging treatment processes. When the aging temperature is below 850 °C, a large number of very small spherical γ′ phases and coarse plate like γ′ are precipitated in the aged samples. The spherical γ′ precipitates are homogeneously distributed in the alloy, while the plate-like γ′ precipitates are distributed along the boundaries of the cells. With increasing aging temperature, the γ′ precipitates are significantly coarsened, and the yield strength (YS) decreases. The strength and ductility reach the best balance herein when the aging temperature ranges from 850 °C to 900 °C.

中文翻译：

---

高温时效对选择性激光熔化 GTD222 高温合金组织和拉伸性能的影响

摘要 GTD222是一种重要的结构合金，用作高温热端零件。在这项工作中，研究了高温 (800–950 °C) 时效处理对通过选择性激光熔化 (SLM) 加工制造的 GTD222 高温合金的显微组织演变和机械性能的影响。经过不同的高温时效处理工艺，得到了不同形貌和尺寸的γ'-Ni3(Al,Ti)沉淀物。当时效温度低于850℃时，时效试样中析出大量极小的球状γ′相和γ′状粗片。球状γ'析出物均匀分布在合金中，而板状γ'析出物沿晶胞边界分布。随着时效温度的升高，γ′相显着粗化，屈服强度（YS）降低。时效温度为850～900℃时，强度和延展性在此达到最佳平衡。