挤压变形和热处理工艺对FGH95合金γ′相析出的影响

Effect of Hot Extrusion and Heat Treatment on the γ′Phase Precipitation in FGH95 Alloy

γ′(Ni3(AlTi))相强化的镍基粉末高温合金(FGH95)采用热挤压工艺可以明显改善合金晶粒大小、γ′相尺寸、分布以及碎化夹杂物,是一种优良的热加工变形的成型工艺。本工作研究FGH95合金经热等静压+热挤压+热处理工艺处理后强化相γ′的析出行为,以及对合金力学性能的影响。实验结果表明:热等静压温度升高,中等尺寸γ′相平均尺寸增大。热挤压后,热等静压态中的γ′相尺寸发生长大,改变大、中、小γ′相的数量比例。固溶热处理后冷却速度明显影响γ′相尺寸变化,盐浴冷却增加中等尺寸γ′相数量,明显改善合金高温塑性。

Deformed by hot extrusion, the grain size, the size and distribution of γ′ phase of the γ′ phase strengthened nickel-base powder superalloy （FGH95） can changed obviously. The means of deformation also can break the impurities, it is a quality hot deformation processing. The precipitation of γ′ phase after HIPed ＋ hot extrusion % heat treatment processing as well as the effects to tensile properties was discussed. The results indicated that, with the HIPed temperature increasing, the average size of middle γ′ phase increased. After hot extrusion, the size of γ′ phase after HIPed is grown, and the number rate among big, middle and litter γ′ phase was changed. The size of γ′ phase was affected by the cooling rate after sold-solution hot treatment obviously, and salt cooling can increase the number of middle γ′ phase, and also can improve the high temperature tensile properties of the supperalloy.