等离子原位合成Ni-Al金属间化合物涂层的组织与性能研究

Study on Microstructure and Properties of Plasma In-situ Synthesis of Ni-Al Intermetallics Coating

利用等离子激发原位反应在碳钢表面合成了Ni—Al金属间化合物涂层。借助金相显微镜、扫描电镜、 X射线衍射仪和显微硬度计对涂层的组织和性能进行了研究。结果表明:当Ni和Al的质量百分比为4:1时,涂层与基体呈冶金结合,无裂纹和气孔等缺陷;涂层的主要组成相为Ni3Al和NiAl;涂层组织为细密的树枝晶;涂层的硬度高于基体,硬度可达630HV;涂层耐蚀性能良好。

Plasma excitation was used for in-situ synthesis of Ni-Al intermetallics coating. The microstructure and properties of the coating were investigated by optical microscope, scanning electron microscope, X-Ray diffractometer and microhardness tester. The results show that excellent bonding between coating and carbon steel substrate is ensured , by the strong metallurgical interface, and the coating is uniform, continuous and almost defect-flee when mass percent of Ni powder and Al powder is 4：1. The microstructure of the intermetallics coating is mainly composed of Ni3Al and NiAl, which is synthesized by in-situ. The microstructures of intermetallics coating is dense fir-tree crystal. The maximum microhardness of the coating is 630HV, which is higher than steel substrate. The performance of Ni-Al intermetallics coating is good.