Prior to thixoextrusion, the microstructural evolution of semi-solid AM50A magnesium alloy prepared by the recrystallisation and partial remelting (RAP) route was investigated.The effect of compressive ratio on micros...Prior to thixoextrusion, the microstructural evolution of semi-solid AM50A magnesium alloy prepared by the recrystallisation and partial remelting (RAP) route was investigated.The effect of compressive ratio on microstructure of semi-solid AM50A magnesium alloy was studied.Furthermore, tensile properties of thixoextruded components were determined.The results showed that the occurrence of recrystallised grains was closely associated with the location of the first liquid formed above the solidus.With prolonging holding time, deformed microstructure was penetrated, causing fragmentation, which resulted in the decrease of average grain size.Moreover, prolonging holding time was favorable for the improvement of the degree of spheroidization due to the increase in the amount of liquid.With the increase in compressive ratio, the size of solid grain decreased, the degree of spheroidization was improved during partial remelting, and the tensile properties of thixoextruded AM50A components were improved.The tensile properties for AM50A magnesium alloy thixoextruded from starting material produced by the RAP route were better than those of the same alloy produced by die-casting and thixomolding.展开更多
In this paper,the formation process,morphology,and electrochemical performance of PEO coatings on AM50 magnesium alloy prepared in low concentration phosphate,aluminate,and phosphate-aluminate electrolytes were system...In this paper,the formation process,morphology,and electrochemical performance of PEO coatings on AM50 magnesium alloy prepared in low concentration phosphate,aluminate,and phosphate-aluminate electrolytes were systematically studied.The results show that the coatings prepared from the phosphate electrolytes have a higher thickness and better corrosion resistance properties compared to the other electrolytes.The coatings prepared from low concentration phosphate-aluminate mixed electrolytes have slightly thinner thickness,a similar coating structure and an order of magnitude lower value of electrochemical impedance compared with phosphate electrolyte coatings.The Coatings prepared from low concentration aluminate electrolytes have the lowest thickness and the worst corrosion resistance properties which gets close to corrosion behavior of the bare AM50 under the same test conditions.Considering application,coatings prepared from single low concentration phosphate electrolytes and low concentration phosphate-aluminate electrolytes have greater potential than single low concentration aluminate coatings.However,reducing the electrolyte concentrations of coating forming ions too much has negative influence on the coating growth rate.展开更多
基金Project(51075099)supported by the National Natural Science Foundation of ChinaProject(E201038)supported by the Natural Science Foundation of Heilongjiang Province,China+2 种基金Project(HIT.NSRIF.2013007)supported by the Fundamental Research Funds for the Central Universities,ChinaProject(2011RFQXG010)supported by the Harbin City Young Scientists Foundation,ChinaProject(LBH-T1102)supported by Specially Postdoctoral Science Foundation of Heilongjiang Province,China
基金Project(51005217) supported by the National Natural Science Foundation of China
文摘Prior to thixoextrusion, the microstructural evolution of semi-solid AM50A magnesium alloy prepared by the recrystallisation and partial remelting (RAP) route was investigated.The effect of compressive ratio on microstructure of semi-solid AM50A magnesium alloy was studied.Furthermore, tensile properties of thixoextruded components were determined.The results showed that the occurrence of recrystallised grains was closely associated with the location of the first liquid formed above the solidus.With prolonging holding time, deformed microstructure was penetrated, causing fragmentation, which resulted in the decrease of average grain size.Moreover, prolonging holding time was favorable for the improvement of the degree of spheroidization due to the increase in the amount of liquid.With the increase in compressive ratio, the size of solid grain decreased, the degree of spheroidization was improved during partial remelting, and the tensile properties of thixoextruded AM50A components were improved.The tensile properties for AM50A magnesium alloy thixoextruded from starting material produced by the RAP route were better than those of the same alloy produced by die-casting and thixomolding.
基金China Scholarship Council for the award of fellowship and funding(No.202006370022).
文摘In this paper,the formation process,morphology,and electrochemical performance of PEO coatings on AM50 magnesium alloy prepared in low concentration phosphate,aluminate,and phosphate-aluminate electrolytes were systematically studied.The results show that the coatings prepared from the phosphate electrolytes have a higher thickness and better corrosion resistance properties compared to the other electrolytes.The coatings prepared from low concentration phosphate-aluminate mixed electrolytes have slightly thinner thickness,a similar coating structure and an order of magnitude lower value of electrochemical impedance compared with phosphate electrolyte coatings.The Coatings prepared from low concentration aluminate electrolytes have the lowest thickness and the worst corrosion resistance properties which gets close to corrosion behavior of the bare AM50 under the same test conditions.Considering application,coatings prepared from single low concentration phosphate electrolytes and low concentration phosphate-aluminate electrolytes have greater potential than single low concentration aluminate coatings.However,reducing the electrolyte concentrations of coating forming ions too much has negative influence on the coating growth rate.
