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采用循环过热与熔融玻璃净化相结合的方法使K4169高温合金获得了14~232 K过冷度。采用透射电子显微镜(TEM)、扫描电子显微镜(SEM)和光学显微镜等手段研究过冷K4169高温合金枝晶形貌以及相组成。研究发现,枝晶形貌、晶粒尺寸和晶间相都会随着过冷度的增加而发生明显改变。同时,系统研究过冷K4169高温合金凝固组织与力学性能之间的关系。实验结果表明,晶粒尺寸和晶间相含量的减小以及Laves相的均匀分布提高了合金的抗拉强度和伸长率,并且当过冷度达232 K时,合金具有最优力学性能,抗拉强度为932.2 MPa,伸长率为6.5%。
Adopting the combination of cyclic overheating and the purification of molten glass, the K4169 superalloy obtained a supercooling degree of 14 ~ 232 K. The dendritic morphology and phase composition of supercooled K4169 superalloy were investigated by transmission electron microscopy (TEM), scanning electron microscopy (SEM) and optical microscopy. It is found that dendritic morphology, grain size and intergranular phase change obviously with the increase of undercooling. At the same time, the relationship between solidification microstructure and mechanical properties of supercooled K4169 superalloy was systematically investigated. The experimental results show that the decrease of the grain size and the intergranular phase content and the uniform distribution of Laves phase increase the tensile strength and elongation of the alloy. When the undercooling reaches 232 K, the alloy has the best mechanical properties, The tensile strength is 932.2 MPa and the elongation is 6.5%.