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对烧结态钨合金进行热挤压、热扭转复合变形,采用分离式霍普金森杆对其进行单轴动态压缩加载,试样发生绝热剪切破坏,表明复合形变后钨合金的绝热剪切敏感性大幅度提高,通过控制加载应变率,获得具有不同演化阶段但未发生破坏的绝热剪切带,采用透射电镜分析绝热剪切带内的微观演化过程,分析绝热剪切带内的动态再结晶机制。结果表明,钨合金绝热剪切带内的组织演化以位错机制为基础,没有孪晶参与,细小的等轴再结晶晶粒通过重复位错增殖、重排和湮灭等过程形成,其动态再结晶行为属于亚晶旋转动态再结晶机制。
The hot-pressed and hot-twisted composite deformation of the sintered tungsten alloy was carried out. The uniaxial dynamic compression loading of the sintered tungsten alloy was carried out and the specimen was subjected to adiabatic shear failure. It is shown that the adiabatic shear of the tungsten alloy after composite deformation is sensitive By controlling the loading strain rate, the adiabatic shear bands with different evolution stages without damage were obtained. The microscopic evolution of the adiabatic shear bands was analyzed by transmission electron microscopy, and the dynamic recrystallization in the adiabatic shear bands mechanism. The results show that the microstructure of Tungsten alloy is based on the dislocation mechanism in the adiabatic shear band and no twins are involved. The fine equiaxed recrystallized grains are formed through the processes of repeated dislocation proliferation, rearrangement and annihilation, Crystallization behavior belongs to the subgrain rotation dynamic recrystallization mechanism.