CMSX-6高温合金定向凝固微观组织的研究

Research on Directional Solidification Microstructure of CMSX-6 Superalloy

采用高速凝固法,在VDF-10定向凝固炉上,制备了CMSX-6镍基高温合金定向凝固试样。研究了距水冷铜板不同高度的凝固组织。结果表明,随着距水冷铜板高度的不断增加,CMSX-6合金的一次枝晶距也不断增大,其铸态组织由细枝状向粗枝状晶演变。同时距水冷铜板高度越低,枝晶干与枝晶间γ'相的尺寸越小,且枝晶间γ'相的形状趋向于规则的立方体形状。同时研究了枝晶间共晶组织的形貌特征,随着距水冷铜板高度增加,共晶尺寸不断地增大。

The directional solidified nickel-base superalloy specimens were prepared by the method of high rate solidification in the VDF-10 directional solidification furnace. The solidification microstructures of different heights from the water-cooled copper disc were studied. The results show that, with the increase of the height, the primary dendrite arm spacing of CMSX-6 alloy increases obviously, the morphology transforms from coarse dendrite to fine dendrite. While with the decrease of the height, the shape of the γ’ precipitates decreases both in the dendrite arm and interdendritic, and the shape of γ’ precipitates in the indendrite tends to regular. At the last of the solidification process, the eutectic structure occurs, with the increase of the height, the shape of the eutectic increases.