Continuous friction stir extrusion production method and production device for ultra-fine grain material

Abstract

The invention provides a continuous friction stir extrusion production method and production device for an ultra-fine grain material. A pair of extrusion wheels is symmetrically arranged, and synchronously rotates in opposite directions to drive at least two blank materials to enter a die cavity from the two sides; a stir bar extends into the die cavity via a center hole of the die cavity to directly reach a converging zone of the at least two blank materials; friction stir processing of the blank materials is realized by rotation of the stir bar; the metal blank materials are fed into a stirzone continuously through rotation of the extrusion wheels; finished product blank materials are rapidly cooled after being extruded by an opening of an extrusion die to form continuous large-length ultra-fine grain type wire products; and forced cooling is performed on the interior of the stir bar through a cooling medium in an operation course.

Description

technical field [0001] The invention relates to the field of advanced manufacturing technology, in particular to a method for preparing a large-length ultra-fine crystal wire and a production device thereof. Background technique [0002] According to the Hall-Petch relationship, grain refinement can significantly improve the strength and hardness of metal materials. At present, the methods for preparing dense and pollution-free bulk ultrafine-grained and nanocrystalline metal structure materials mainly adopt various severe plastic deformation (SPD) processes. In the process of preparing ultra-fine-grained materials by SPD method, a large number of crystal defects are introduced, and most of the grain boundaries are in a non-equilibrium state. Therefore, ultra-fine-grained materials prepared by SPD generally have the problem of high strength but low plasticity. In recent years, friction stir processing (Friction Stir Processing, FSP) has received more and more attention. Com...

AI Technical Summary

Problems solved by technology

In the process of preparing ultra-fine-grained materials by SPD method, a large number of crystal defects are introduced, and most of the grain boundaries are in a non-equilibrium state. Therefore, ultra-fine-grained materials prepared by SPD generally have the problem of high strength but low plasticity.

In recent years, friction stir processing (Friction Stir Processing, FSP) has received more and more attention. Compared with ultrafine-grained materials prepared by SPD, FSP has a uniform and stable ultra-fine-grained structure and excellent mechanical properties. However, this method , ultrafine-grained materials are only formed in the stirring processing area, and this method can only obtain bulk materials or surface modification of original products

There is no ideal solution for the preparation of long-length wires with ultra-fine grains, uniform and stable structure, and excellent mechanical properties.

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