The present work focuses on a new method combining cast-infiltration with thermal spraying technology to improve the surface corrosion resistance of magnesium alloy.A zinc-based alloy layer was fabricated on the surfa...The present work focuses on a new method combining cast-infiltration with thermal spraying technology to improve the surface corrosion resistance of magnesium alloy.A zinc-based alloy layer was fabricated on the surface of AZ91D magnesium alloy. The microstructure of the layer was characterized by scanning electron microscopy equipped with an energy dispersive X-ray spectroscopy(EDS).The phase constituent of these alloys was identified by X-ray diffractometry(XRD).The analysis results reveal that a zinc-based alloy layer with a thickness of 700μm can form on the surface of AZ91 alloy matrix.The layer is composed of Mg7Zn3,MgZn and a small amount of α-Mg solid solution.The results indicate that the corrosion-resistance of the specimen with a zinc-based alloy layer is much better than that of the specimen without the layer after being immersed in 5%NaCl solution for 240 h, and the layer is more protective for the AZ91 alloy.展开更多
Abstract： In order to improve the surface hardness and wear resistance of magnesium, Al-13%Si （mass fraction） alloy coating was deposited on pure magnesium by droplet spraying process. The microstructure was studie...Abstract： In order to improve the surface hardness and wear resistance of magnesium, Al-13%Si （mass fraction） alloy coating was deposited on pure magnesium by droplet spraying process. The microstructure was studied by electron probe microanalysis and X-ray diffraction. The micro-hardness and wear resistance of coating were investigated in comparison with those of the substrate. It is found that the coating layer is composed of a-Al cellular due to rapid solidification. Formation mechanism of the coating is due to the obstruction of diffusion by in-situ formed Mg2Si in interracial layer. The coating exhibits higher hardness compared to that of the Mg substrate. As result of its high hardness, the wear resistance of the coating layer is about ten times that of the substrate. The droplet spraying process demonstrates that the magnesium surface can be strengthened by using the existing Al-Si alloys.展开更多
A new brush plating process with a soluble anode of nickel was introduced. TDY112 brush plating solution was used on the No.20 carbon steel substrate. It has the higher deposit velocity, better properties and lower co...A new brush plating process with a soluble anode of nickel was introduced. TDY112 brush plating solution was used on the No.20 carbon steel substrate. It has the higher deposit velocity, better properties and lower cost. Scanning electronic microscopy(SEM), optical microscope, microhardness test and wear test were adopted to detect the surface quality and the properties of the coating, such as micrograph, microstructure, micro-hardness wear resistance and adherence between the coating and the substrate. The experimental results showed that the suitable technological parameters to be used, the coatings had better the surface quality, higher hardness and wear resistance.展开更多
文摘The present work focuses on a new method combining cast-infiltration with thermal spraying technology to improve the surface corrosion resistance of magnesium alloy.A zinc-based alloy layer was fabricated on the surface of AZ91D magnesium alloy. The microstructure of the layer was characterized by scanning electron microscopy equipped with an energy dispersive X-ray spectroscopy(EDS).The phase constituent of these alloys was identified by X-ray diffractometry(XRD).The analysis results reveal that a zinc-based alloy layer with a thickness of 700μm can form on the surface of AZ91 alloy matrix.The layer is composed of Mg7Zn3,MgZn and a small amount of α-Mg solid solution.The results indicate that the corrosion-resistance of the specimen with a zinc-based alloy layer is much better than that of the specimen without the layer after being immersed in 5%NaCl solution for 240 h, and the layer is more protective for the AZ91 alloy.
基金Project(KZJ-48)supported by the Science and Technology Development Program of Qingdao,ChinaProject(51208288)supported by the National Natural Science Foundation of ChinaProject(BS2011CL032)supported by the Research Award Fund for Outstanding Youngand Middle-aged Scientists of Shandong Province,China
文摘Abstract： In order to improve the surface hardness and wear resistance of magnesium, Al-13%Si （mass fraction） alloy coating was deposited on pure magnesium by droplet spraying process. The microstructure was studied by electron probe microanalysis and X-ray diffraction. The micro-hardness and wear resistance of coating were investigated in comparison with those of the substrate. It is found that the coating layer is composed of a-Al cellular due to rapid solidification. Formation mechanism of the coating is due to the obstruction of diffusion by in-situ formed Mg2Si in interracial layer. The coating exhibits higher hardness compared to that of the Mg substrate. As result of its high hardness, the wear resistance of the coating layer is about ten times that of the substrate. The droplet spraying process demonstrates that the magnesium surface can be strengthened by using the existing Al-Si alloys.
文摘A new brush plating process with a soluble anode of nickel was introduced. TDY112 brush plating solution was used on the No.20 carbon steel substrate. It has the higher deposit velocity, better properties and lower cost. Scanning electronic microscopy(SEM), optical microscope, microhardness test and wear test were adopted to detect the surface quality and the properties of the coating, such as micrograph, microstructure, micro-hardness wear resistance and adherence between the coating and the substrate. The experimental results showed that the suitable technological parameters to be used, the coatings had better the surface quality, higher hardness and wear resistance.
