A kind of deep-cooling surface layer continuous rolling preparation method of gradient strip

Abstract

The invention provides a deep-cooling surface-layer continuous-rolling preparation method for a gradient strip. Grains in the surface-layer area are promoted to be refined through plastic deformation of the surface layer of a material, and meanwhile, recrystallization of ultra-fine grains in the plastic deformation process is restrained through ultralow-temperature deformation, so that a nano-structure is formed on the surface of the material; through multi-pass deep-cooling surface-layer rolling, the strip of a gradient structure is formed through a rolled piece, the surface layer of the material is of an ultra-fine grain structure, and coarse grains are located on the central area of the material; and compared with a material which is prepared through traditional cold rolling, the strength of the material is greatly improved under the condition that the material has better plasticity. Compared with the prior art that deep-cooling surface-layer rolling is only suitable for pure aluminum and aluminum alloy materials currently, through the technique, the tenacity of the material is hardly reduced, and the strength of the material can be improved by 30% or over.

Description

technical field

[0001] The invention belongs to the technical field of metal material rolling, and in particular relates to a method for preparing gradient strip material by deep-cooling surface layer continuous rolling. Background technique

[0002] At present, ultra-fine-grained metal materials have attracted the attention of scientists for a long time in the past, and people have developed a large number of methods to prepare these materials, such as equal channel extrusion technology, cumulative stack rolling technology, high-pressure torsion technology, etc. However, it has been found that for ultrafine-grained materials, as the strength of the material increases, the toughness of the material decreases sharply.

[0003] Researchers have discovered that a gradient structure is formed in the metal material, which can simultaneously achieve good toughness and strength of the material. Gradient materials to form an ultra-fine-grained material structure on the surface of t...

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