Research On Thermal Spraying Ni/Al Coating On The Surface Of AZ91D Magnesium Alloy

Magnesium alloys are promising materials lightweight constructions due to their high specific strength and stiffness. Compared with other metal structural materials, the intensity and rigidity of magnesium and alloy are highter, it is strong to reduce and shake damping, electromagnetic shielding and ability to resist radiation, cut and process of good performancly, easy to retrieve the advantage of utilizing etc.However, the use of Mg alloys anodizing,electroplating and conversion coating have been used to improve their surface properties The article has shown that the thermal spray process has an enormous potential for the surface modification of Mg alloys.Ni/Al coating on magnesium alloy AZ91D substrate was fabricated by flame spraying. The microstructure and composition of the coating were analyzed by scanning electronic microscope(SEM)and electron probe microanalysis(EPMA), Corrosion resistance and wear resistance of the coating were tested. Results are as follows:1,thermal spray was investigated for improving the surface performance of magnesium alloy. The coatings on AZ91 magnesium alloy were prepared by thermal spraying Ni/Al coatings can protect the magnesium alloy substrate, and the coating was homogeneous and dense.2,The corrosion resistance and wear resistance of coatings can be improved by adding moderate Y.3,The results show that a diffusion fusion layer is formed between the substrate and the coating, and the integrating strength is proved.4,In the flame spraying Ni/Al composite powders prepared in the magnesium alloy surface coating, when added to spray powder of rare earth Y content of about 1%, the obtained coating hardness, corrosion resistance, wear resistance as well as the coating and the substrate bonding strength than good, by the proliferation of heat treatment, its overall performance showed some improvements.