【摘要】 M963合金的凝固顺序为: L→L+γ→L+(γ＇+MC)+γ→(γ+γ＇)+(γ+MC)+γ→(γ+γ＇)+(γ+MC)+γ+γ＇;凝固组织呈树枝状结构,由γ固溶体基体、γ＇析出相及分布在枝晶间区的骨架状MC碳化物和(γ+γ＇)共晶组成;碳降低合金的液相线温度和(γ+γ＇)共晶温度,提高MC碳化物的形成温度,增加MC碳化物的体积分数,降低(γ+γ＇)共晶的体积分数;高熔点元素W和Co在枝晶干偏聚, Al,Ti,Nb,Cr和Mo在枝晶间偏聚.更多还原

【Abstract】 The solidification behavior and as-cast microstructure feature of a cast nickel-base superalloy M963 have been investigated by SEM (EDXS) and DTA. The results show that the solidification sequence of M963 superalloy is as follows: L→L+γ→L+(γ’ + MC)+γ→ (γ+ γ’) + (γ + MC)γ→ (γ → γ’) + (γ + MC)+γ + γ’. The as-cast microstructure is dendritic and consists of γ solid solution matrix , γ’ precipitate, the script-like MC carbide and (γ + γ’) eutectic in the interdendritic region. Carbon causes a decrease in liquidus and (γ + γ’) eutectic temperature, and an increase in MC carbide formation temperature, thus decreases the volume fraction of (γ + γ’) eutectic and increases the volume fraction of MC carbide. The refractory element W and Co are rich in dendrite arm but Al, Ti, Nb, Cr and Mo rich in interdendritic region.更多还原