【摘要】 将Φ40mm×50mm的AZ31镁合金圆棒经变通道角挤压(Change channel angular extrusion,CCAE)成厚度约为5mm的板材。通过TEM观察表明,AZ31镁合金的形核机制主要是动态再结晶形核。结果表明,经CCAE变形后,由晶粒的剪切破碎和动态再结晶使得镁合金晶粒明显细化。内角、挤压比、挤压温度和挤压速率等对板材的显微组织结构有重要的影响。在100~450℃温度范围内进行CCAE变形,AZ31镁合金的晶粒尺寸随变形温度的升高而增大。AZ31镁合金经CCAE热变形后,合金的综合力学性能得到改善。更多还原

【Abstract】 AZ31 magnesium alloy sheets with thickness of about 5mm were made by change channel angular extrusion(CCAE) from an ingots with dimension of Φ40mm×50mm.TEM observation reveals that the grains of AZ31 alloy are refined by shear breaking of original grains and dynamic recrystallization during CCAE deformation.The processing parameters including internal angle Φ,extrusion ratio λ,extrusion temperature T,and extrusion velocity,exhibit great effects on microstructure of the sheets. It is found that the grain size increases with increasing extrusion temperature in the experimental temperature range of 100℃ to 450℃.The combined mechanical properties of the alloy are improved by CCAE.更多还原