Cryogenic preparation method of ultra-fine grain material with assistance of electric pulse and confining pressure

Abstract

The invention relates to the technical field of ultra-fine grain material preparation, in particular to a cryogenic preparation method of an ultra-fine grain material with assistance of electric pulseand confining pressure. The material deforms in the ultra-low temperature state, the grain recrystallization process is restrained, and due to repeated cryogenic deformation, the ultra-fine grain material is formed. In the deformation process, a large amount of dislocation is accumulated, and the strength of the material is greatly improved. During plastic deformation, a certain confining pressure is applied, the internal micro-defect in intensive deformation of the material is restrained, the material strength is further improved, and meanwhile the anti-fatigue and anti-corrosion performancecan be improved. During plastic deformation, electric pulse is applied, the low-temperature deformation plasticity of the material is improved, resistance to deformation is reduced, the processing frequency of the material is increased, and the strength and plasticity are synchronously improved.

Description

technical field [0001] The invention relates to the technical field of preparation of ultra-fine-grained materials, in particular to a cryogenic preparation method of ultra-fine-grained materials assisted by electric pulses and confining pressure. Background technique [0002] At present, the means of preparing ultra-fine-grained metal materials include equal-diameter angular extrusion, cumulative rolling, multi-directional compression, high-pressure torsion, etc., but they all have common disadvantages, that is, with the increase of cumulative deformation, grain refinement, The strength increases, but the toughness drops sharply, which restricts the grain refinement processing and the machinability of the finished material. When the metal is deformed, the current is applied, the current promotes the movement of dislocations and overcomes the obstacles in the movement, reduces the influence of metal work hardening, and greatly improves the formability. [0003] The degree o...

AI Technical Summary

Problems solved by technology

[0003] The degree of grain refinement of processing methods such as multi-directional compression and equal-channel extrusion at room temperature and temperature state increases with the increase of processing times, the refinement speed slows down, and the dynamic recovery and dislocation proliferation tend to be in dynamic balance, further reducing Difficulty with grain size

Due to the severe plastic rheology of the material, the inconsistency of the internal rheology leads to microscopic pores and defects, and the fatigue and corrosion resistance of the material are weakened

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