微量元素B对镍基单晶高温合金凝固组织的影响

Effect of Trace Element Boron on the Solidification Microstructure of Single-crystal Nickel-based Superalloy

通过籽晶法制备了不同B含量的镍基单晶高温合金DD90,并研究了B元素对合金枝晶组织、共晶组织和碳化物形貌的影响。结果表明:随着合金中B元素含量的增加,二次枝晶组织逐渐变粗大,三次枝晶组织越来越明显,同时,合金中的碳化物增多,而共晶组织数量明显减少。

Single-crystal nickel-based superalloys DD90 with different boron contents were prepared by seed growth technique, and the influences were researched of B element on dendritic structure, eutectic structure and carbide morphology. The results show that with boron content increasing, the secondary dendrites gradually become thicker, the third dendrites become more distinct, and meanwhile, the carbides increase while the eutectic microstructure obviously decreases.