Investigation On Magnesium Alloy Sheet Manufactured By Strip Casting And Downstream Rolling

There are some advantages on molding by casting rolling, such as shorten flow, saving energy consumption, reducing cost. Magnesium alloy of casting rolling as a new method of machine shaping has been hotspot of research on engineering domain and learning domain in recently years, sheets of cast rolling need next rolling, The sheets have good surface quality and internal soundness, The sheets are available to pressing after rolling.In this paper, technology of AZ31 magnesium alloy of casting rolling was introduced, effects of homogeneous heat treatment on microstructures and mechanical properties of AZ31 sheet of casting rolling were analyzed, under 400℃, rolling about AZ31 magnesium alloy of casting rolling, research about effects of different fashion of rolling on microstructures and mechanical properties of AZ31 sheet of casting rolling, and grain refinement mechanism were discussed. The microstructure and tensile strength between the sheets manufactured by casting rolling and extrusion were compared.(1) The results showed that mostly columnar existed in the AZ31 magnesium alloy of casting rolling. Dendritic segregation and second phases Mg₁₇Al₁₂ existed in the microstructure of the sheet. After homogeneous heat treatment, the dendritic segregation disappeared and coarse second phases changed into many small grain. It's result in the decreasing of tensile strength and increasing of the elongation.(2) Hot rolling on AZ31 sheet of casting rolling, the sheets have good profile and surface quality. While the effects of different fashion of rolling on microstructures and mechanical properties of AZ31 sheet of casting rolling has been researched. Three sample has been intercepted from AZ31 sheet of casting rolling, one was transverse rolling , another was longitudinal rolling, last was cross rolling, the result showed that the grain is very equality after rolling, the grain of transverse rolling is bigger, it's mostly size is 10um-20um,rare is less than 10um,the grain size of longitudinal rolling is close to cross rolling, the grain size is 10um around, the grain size of a small number of longitudinal rolling is less than 10um,the grain size of mostly of cross rolling is less than 10um. The specific elongation of cross rolling is better than both transverse rolling and longitudinal rolling, the best number is 22.5%.The tensile strength of longitudinal rolling is very close to cross rolling, the tensile strength of cross rolling is lowed than the tensile strength of both transverse rolling and longitudinal rolling.( 3 ) Through contrast microcosmic structure and tensile strength between sheet of casting rolling and sheet of extrusion. The result is: as-casting, stretcher and tensile strength of sheet of extrusion is more better than sheet of casting rolling. Through homogeneous heat treatment and hot rolling, microcosmic structure and tensile strength of sheet of casting rolling is close to sheet of extrusion.