Pulse impacting type coordinative multi-directional rotating and rolling pressing preparation method of gradient nanocrystalline of board

Abstract

The invention discloses a pulse impacting type coordinative multi-directional rotating and rolling pressing preparation method of a gradient nanocrystalline of a board. The method is characterized inthat the surface of a metal board is impacted through a high-intensity steel impacting pin in a high-frequency pulse type impacting mode, and the impacted board surface is rolled and pressed in a rapid multi-directional rotating and rolling pressing mode, thus the board surface layer is subjected to strong plastic deformation, and the surface is induced to realize nanocrystallization, and as a result, the gradient nanocrystalline is prepared. The method has the advantages that (1) the surface nanocrystallization processing period is short; the pulse impacting and the multi-directional rotatingand rolling pressing are synchronously carried out, so that the operation period of impacting and then rolling and pressing can be greatly reduced; (2) the surface nanocrystallization effect is obvious; the accumulated plastic deformation of the surface layer of a metal material is greatly improved under the coordination effect of the impact load and the extruding load, and moreover, the dynamicplastic flowing capacity of the surface layer of the material can be effectively improved; and (3) the surface roughness of the material is reduced; and a protruded part on the surface of the materialcan fills a concave part based on the plastic flowing capacity of the material and under the multi-directional rotating and rolling pressing effects.

Description

technical field [0001] The invention belongs to the technical field of metal material surface strengthening and modification, and specifically relates to a method for preparing plate gradient nanocrystals by pulsating impact and multi-directional rotating rolling. Background technique [0002] In the service environment, the failure of metal materials mostly originates from its surface, and the fatigue, corrosion and wear of materials are very sensitive to its surface structure and performance. Research in recent years has found that surface nanotechnology can prepare a gradient nanostructure layer with a certain thickness on the surface of metal materials, which effectively improves the overall mechanical properties and service behavior of materials. Surface nanotechnology is a kind of material surface modification technology, which uses various physical and chemical methods to promote the generation of nano-scale grain layers on the surface of metal materials, and greatly ...

AI Technical Summary

Problems solved by technology

[0005] For the surface machining method in the surface self-nanoization technology of metal materials, the impact load will increase the surface roughness of the material. The treatment method of impact first and then rolling is not only high cost, long cycle and complicated operation process, but also the traditional rolling technology surface In order to solve the problems such as the inconspicuous effect of nanometerization, the present invention provides a method for preparing plate gradient nanocrystals with pulsating impact combined with multi-directional rotary rolling. Multi-directional rotary rolling is carried out while the impact load is acting, combining the advantages of the two loading methods , which not only increases the cumulative plastic deformation of the surface of the material, but also effectively enhances the dynamic plastic flow of the surface of the material, thereby significantly improving the effect of nano-material surface

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