预处理对一种含Re、Ru单晶高温合金显微组织的影响

Effect of Pretreatment on the Microstructure of a Single Crystal Superalloy Containing Re and Ru

在单晶炉中制备了一种含Re.Ru的高代单晶高温合金,在1310℃温度下预处理,分别保温0.5h、1h.2h、4h、8h、16h、32 h后空冷,用OM和SEM分析了合金铸态和保温不同时间后的组织。研究结果表明,合金铸态组织由枝晶干细小γ'相、枝晶间粗大γ'相、共晶组织、极少量微孔和碳化物组成。随着预处理时间的增加,保温从0.5 h到4h,微孔的尺寸、数量和体积分数稍微增加,保温8 h后,微孔的数量、尺寸和体积分数显著增多;微孔由不规则形状逐渐变为规则的圆形或椭圆形。随着预处理时间的增加,共晶含量逐渐减少,合金元素枝晶偏析程度减小;保温从0.5 h到4 h,γ'相尺寸稍微增加,保温8 h后,γ'相尺寸显著增加。

The high generation single crystal superalloys containing Re and Ru were manufactured in a directionally solidified furnace. The pretreatment was carried out at 1 310 ℃ and held for 0.5 h, 1 h, 2 h, 4 h, 8 h, 16 h and 32 h, respectively. The as-cast microstructure and the microstructure after pretreatment for different time were studied by OM and SEM. The results showed that the as-cast microstructure was made up of the fine γ′ phase in dendrite, the coarse γ′ phase, γ/γ′ eutectic, very little micropores and carbides in interdendrite zone. With the increasing of the pretreatment time, the size, number and volume fraction of micropores were slightly increased as the insulation from 0.5 h to 4 h, but they were significantly increased after the insulation 8 h. Micropores gradually changed from irregular shape to round or oval shape. The volume fraction of γ/γ′ eutectic and element segregation ratios of the alloy were gradually decreased with the increasing of the pretreatment time. The size of the γ′ phase was slightly increased as the insulation from 0.5 h to 4 h, but that was significantly increased after the insulation 8 h.