| The task of the research is to reheat ZL112Y aluminum alloy in the process of the high-frequency heating and to form a component of kickstand of generator of the type of JH70 motorcycle in semi-solid die casting processing.With a high-frequency induce heating equipment and a device for temperature measuring, reasonable semi-solid processing parameters, an appropriate semi-solid remelting temperature, heating power and speed, of ZL112Y aluminum alloy in the process of the high-frequency reheating and effects of these parameters on thixotropic behaviors of billets and microstructures of the alloy were searched. Results of the experiment show that, 1) proper semi-solid remelting temperatures of the alloy is in the range of 570℃-571℃; 2) in the condition of optimized reheating processing, the temperature deviation in a billet is O℃-1℃; 3) dendritical colonies of a phase in original billet changed into isolated grains with forms of nodules and granule, which may satisfy the need of semi-solid thixoforming forming in theory.The component was successfully formed in practice in semi-solid die casting processing by the semi-solid processing parameters obtained in laboratory at the locale of the factory of Chongqing JiuFang casting limited liability Company of JiaLing group.During the semi-solid die casting processing, appropriate semi-solid casting parameters and the sizes of ingate area were researched ,also, the microstructures and mechanical properties of the component in semi-solid die casting processing were investigated .And effects of casting parameters on the performances of the component in semi-solid die casting processing and heat treatment on microstructures and mechanical properties of components made of A1 alloy were observed. A reasonable processing for an eligible semi-solid component in practice was basically obtained.The strength and relative elongation of the specimens were measured, which were obtained from the components formed by semi-solid die casting and liquid die casting and these components with heat treatment, and the mechanical properties of the specimens were compared with each other. Further more, the Brinell hardness and Rockwell hardness of the specimens were measured. Meanwhile, Structural evolutions of ZL112Y aluminum alloy in procedures of semi-solid die casting were investigated.The structures of solid a phase of original billet, pierce block in the chamber of die-casting machine, ingate block in die-casting mould and specimens atdifferent locations in a semi-solid die casting component were observed.Results of observation and analyses show that: the maximum average value of tensile strength of the components formed by semi-solid die casting, 170.50MPa, is 9.79% greater than 155.29MPa, which is the average value of tensile strength of the components formed by liquid die casting; at the same time, 209.90MPa is the maximum(not average) value of tensile strength of the components formed by semi-solid die casting with heat treatment, which is much greater than 185.39MPa-the maximum value of the components formed by semi-solid die casting without heat treatment and 172.62MPa 梩he maximum value of the components formed by liquid die casting and 112.85MPa-the maximum value of the components formed by liquid die casting with heat treatment. Results show that semi-solid metal forming is superior to liquid metal forming if the parameters of the processing are well controlled: it can get the parts of higher integrity with superior mechanical properties, and there is a trend that the properties of the parts formed by semi-solid die casting with heat treatment are greater than that without heat treatment .While the part formed by liquid die casting can not be heat treated for its mechanical properties will be sharply reduced after heat treatment. Results of observing and analyzing the structures and mechanical properties of the specimens show that the mechanical properties will be enhanced if further optimizing the processing of semi-solid die casting can be carried out an...
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