Ultralow-temperature impact dynamic load large plastic deformation device and method

Abstract

The invention belongs to the technical field of ultralow-temperature impact dynamic load deformation metal block material ultra-fine grain / nanocrystalline preparation, and discloses an ultralow-temperature impact dynamic load large plastic deformation device and method. High-speed dynamic loading plastic deformation is continuously carried out at the liquid nitrogen temperature; dynamic recovery in the metal plastic deformation process is inhibited at the ultralow temperature; and higher deformation energy is obtained, the dislocation density is effectively accumulated, and an ultra-fine grain / nanoscale metal material is obtained. A bottom plate of the disclosed ultralow-temperature impact dynamic load large plastic deformation device is placed on an open flat ground, an inner cylinder and an outer cylinder are placed on the bottom plate, a metal sample is fixed in a follow-up impact mold, the follow-up impact mold is connected with a hammer rod of a pneumatic impact hammer in the device, and the device is filled with liquid nitrogen. The device and the method have the characteristics of ultralow temperature, impact of the sample by the follow-up impact mold and continuous high-speed dynamic loading, the preparation of block metal ultra-fine grains / nanocrystals is realized, and the mechanical property is obviously improved.

Description

technical field [0001] The invention belongs to the technical field of ultra-fine crystal / nano crystal preparation of ultra-low temperature impact dynamic load deformed metal block materials, and aims to design an ultra-low temperature impact dynamic load large plastic deformation device and method. Background technique [0002] At present, in order to obtain the refinement effect of ultrafine crystals / nanocrystals, it is necessary to carry out a large deformation process on the metal or to obtain a large cumulative deformation of the metal, that is, a large plastic deformation, to achieve higher deformation strain and introduce complex Stress / strain state (eg strong shear deformation). At present, the existing large plastic deformation technologies include: high-pressure torsion, equal-diameter angular extrusion, cumulative stack rolling, etc. Large plastic deformation technology is one of the main methods for preparing nano-metal materials due to its simplicity, high effi...

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Problems solved by technology

[0007] 1) Existing deformation processes and equipment mainly adopt plastic deformation to metals at room temperature or medium and high temperature conditions, but it is difficult to obtain low temperature conditions; 2) Conventional processing methods can obtain plastic deformation under static and quasi-static conditions, but are relatively difficult It is difficult to obtain large plastic deformation under high-speed impact; 3) It is difficult to obtain continuous plastic deformation with existing deformation methods, and the cumulative amount of plastic deformation is insufficient; 4) It is difficult to implement the existing metal micronization preparation technology for bulk metal

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