论文部分内容阅读
采用真空电弧镀的方法在Ni3Al基合金IC6上涂覆了NiCrAlY ,NiCoCrAlY和NiCoCrAl YHf三种MCrAlX包覆涂层 ,测试了室温拉伸和 110 0℃ 90MPa高温持久性能。结果表明 ,这三种涂层对室温拉伸性能均无明显影响 ,NiCoCrAlY和NiCoCrAlYHf涂层对高温持久性能也无太大影响 ,但NiCrAlY涂层却使IC6基体合金的持久寿命大幅度降低。利用扫描电镜和电子探针分析了NiCrAlY涂层在涂覆态和应力持久拉伸断裂状态的显微组织和成分变化 ,在应力持久拉伸断裂试样中发现了规则块状的AlN ,本文认为硬脆AlN在涂层表层中局部的析出可能是导致NiCrAlY涂层基体合金持久寿命明显下降的主要原因
Three kinds of MCrAlX coatings were coated on Ni3Al-based alloy IC6 by vacuum arc plating. The tensile properties at room temperature and long-term durability at 110 0 ℃ and 90MPa were tested. The results show that the three coatings have no significant effect on the tensile properties at room temperature. The NiCoCrAlY and NiCoCrAlYHf coatings have not much effect on the high temperature durability properties. However, the NiCrAlY coating greatly reduces the long-term durability of the IC6 matrix alloy. The changes of microstructure and composition of NiCrAlY coating under the condition of tensile stress and tensile fracture were analyzed by scanning electron microscopy and electron probe. AlN was found to be regularly massive in tensile long-time tensile fracture specimen. The local precipitation of hard and brittle AlN in the coating surface may be the main reason for the significant decrease of the durable life of the NiCrAlY coating matrix alloy