| In this paper, AZ31 magnesium alloy cast rod was produced by semicontinuous casting machine. Microstructure of AZ31 magnesium alloys were analyized by means of the SEM and TEM. Homogenizing technics of AZ31 magnesium alloy casting is researched. Plastic deformation condition explored through thermal simulation examination by Gleeb-1500 machine. The thin wall AZ31 magnesium alloy Tubing with high precision manufactured by extrusion technology, The influence of extrusion ratio and deformation temperature on precision of extruded AZ31 magnesium alloy Tubing are researched by 630t and 2000t extruding machine. Moreover, the plastic deformation behavior of extruded AZ31 magnesium alloy is have also been studied. Technics of high precision AZ31 magnesium alloy Tubing has been acquired.The result of semicontinuous casting show precipitated phase is thin and grain is small than gravity casting. The result of homogenizing annealing examination show suitable technics is 420℃×12h. It is indicated from thermal simulation examination that plastic deformation temperature and strain rate is 360~420℃and 1s-1. AZ31 magnesium alloy Tubing extruded at 390℃can gain dimensions accuracy. The results of extruded show that dynamic recrystallization occurs during hot extrusion. Extrusion deformation can fine the grains of magnesium alloy and improve its properties remarkably. With an increase in extrusion ratio, the grain size decrease initially and then increase, and the size of grain changes from as-cast 200～300μm to extruded 13～25μm. And, In terms of comprehensive properties, the suitable annealing technics system of AZ31 magnesium alloy product is 250℃×2h. Annealing may lead to the weakness of texture to 1/2~2/3 of (0002),(1010),(1011),(1012). Fracture surface analysis revealed that the extruded AZ31 alloys with an annealing statuses exhibit a characteristic of ductile facture during tension at room temperature,tensile-strength is 270MPa of AZ31 magnesium alloy,elongation percentage is 24.1%. |
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