摘要
In this work, microarc oxidation(MAO) technology was used to form oxide ceramic coating on the surface of aluminum alloy. The combined additives nano-TiOand nano-ZnO were added into the silicate electrolyte, and the effect of the compound nano-additive on microstructure and properties of MAO coating was investigated. The results show that compared with those of the nano-additive-free coating formed on aluminum alloy, the thickness, hardness, abrasion resistance and corrosion resistance of the nano-additive-containing coating are obviously improved. The surface of coating with nanoadditive becomes smooth, dense, and there are less porosities and microcracks. Moreover, the content of crystal phase a-AlOand y-AlOincreases visibly on the nano-additive-containing MAO coatings, and new phases AlTi and ZnTiare detected in the coatings, which are mainly contributed to the excellent corrosion resistance and abrasion resistance of the film. When the contents of nano-TiOand nano-ZnO are, respectively, 4 and 2 g-L, the film has better comprehensive performance, the thickness and hardness of the film could reach 52 μm and HV 692,respectively.
In this work, microarc oxidation(MAO) technology was used to form oxide ceramic coating on the surface of aluminum alloy. The combined additives nano-TiO_2 and nano-ZnO were added into the silicate electrolyte, and the effect of the compound nano-additive on microstructure and properties of MAO coating was investigated. The results show that compared with those of the nano-additive-free coating formed on aluminum alloy, the thickness, hardness, abrasion resistance and corrosion resistance of the nano-additive-containing coating are obviously improved. The surface of coating with nanoadditive becomes smooth, dense, and there are less porosities and microcracks. Moreover, the content of crystal phase a-Al_2O_3 and y-Al_2O_3 increases visibly on the nano-additive-containing MAO coatings, and new phases Al_3Ti and Zn_(0.6)Ti_(0.4) are detected in the coatings, which are mainly contributed to the excellent corrosion resistance and abrasion resistance of the film. When the contents of nano-TiO_2 and nano-ZnO are, respectively, 4 and 2 g-L^(-1), the film has better comprehensive performance, the thickness and hardness of the film could reach 52 μm and HV 692,respectively.
基金
financially supported by the International Technology Cooperation Plan in Guizhou Province (No.2012-7001)
