单晶空心叶片榫头再结晶行为研究

Research on Recrystallization Behavior of Single-crystal Hollow Blade Tenon

摘要:

为了更好的研究温度和载荷对镍基单晶空心叶片榫头位置的再结晶行为的影响，本实验首先对单晶试样施加不同载荷，然后在不同的温度下进行固溶处理，处理后的试样在光学显微镜和扫描电子显微镜进行组织分析。结果表明：不同载荷下的DD5单晶试样经1230℃/4h，ac热处理后，随着载荷增加，受载荷影响区域深度增加，该区域枝晶间空间增大，未溶解的共晶组织周围弥散分布大量与γ相共格的γ′相颗粒物，γ′相粒子以胞状形式重新析出，尺寸和深度随载荷的增大而增加；经1315℃/4h，ac.热处理后发生再结晶现象，随着载荷增加再结晶区域增大，受载荷影响区域的枝晶干发生钝化，枝晶干与枝晶间界限消失，再结晶晶粒间存在γ/γ′共晶组织。

Abstract:

In order to better understand the temperature and load effect on recrystallization behavior of DD5 single-crystal hollow blade tenon. Samples with different load were heat treated by different solution temperature in a furnace. Optical microscope and scanning electron microscope were used to study the microstructure of recrystallization and size distribution of γ’ phase after solution treatment. Results show that there were no new grains found after solution treatment at 1230°C/4h, ac. However, the depth of affected area was increasing with the increase of bearing load and the size and depth of recrystallized cellular structure with newly-formed γ" phase particles increased with the load increases below the solution temperature. Besides, the recrystallized nuclei begin from the dendrite when the solution treatment at 1315°C/4h, ac. The dendrite arms was passivated and the boundary between dendrite arm and interdendritic space disappeared and γ/γ" phase eutectic structure existed between dendrites in the recrystallization area. Moreover, the recrystallization area and the primary dendritic size gradually increased with the increase of load above the solution temperature.