A method for strengthening and toughening magnesium alloy strips

Abstract

The invention discloses a method for strengthening and toughening magnesium alloy strips. Aiming at the problems of easy oxidation, coarse crystal grains, limited improvement of strength and plasticity, and high energy consumption in the traditional heat treatment process of magnesium alloys, the invention first uses electric pulses to treat magnesium alloys. The alloy strip is subjected to rapid solution treatment, and then processed by rolling, the primary cold-rolled strip is subjected to aging treatment, the aging-treated strip is subjected to secondary cold-rolling, and finally the secondary cold-rolled strip is subjected to electric pulse induction. Recrystallization treatment uses electric pulses to quickly refine the matrix grains and precipitated phases to hinder the growth of grains, so as to obtain a structure with fine and uniform matrix grains and a dispersed distribution of strengthening phases. Through the synergistic toughness of fine grains and precipitated phases Chemical reaction to prepare high-strength and high-toughness magnesium alloy strips. Compared with the magnesium alloy strip in the prior art, the strength and elongation after fracture of the magnesium alloy strip prepared by the process of the invention are respectively increased by more than 10% and 30%.

Description

technical field [0001] The invention belongs to the technical field of metal materials, and in particular relates to a method for strengthening and toughening magnesium alloy strips. Background technique [0002] As the lightest engineering metal structure material, magnesium alloy has the advantages of light specific gravity, high specific strength and specific stiffness, good thermal conductivity, strong electromagnetic shielding ability, good damping and shock absorption, easy cutting and recycling, etc. Information, transportation and other industries have a wide range of applications, and are known as "the most promising green engineering materials in the 21st century". [0003] With the development of transportation tools (such as automobiles, high-speed rail, etc.) towards light weight and electronic devices towards miniaturization, light weight, and multi-function, higher and higher requirements are put forward for the performance and processing performance of magnes...

AI Technical Summary

Problems solved by technology

The strength and plasticity of magnesium alloys can be improved at the same time through grain refinement, but the degree of grain refinement to improve the strength of magnesium alloys is limited. Distributed strengthening phase realization

[0004] At present, heat-treatable magnesium alloys are basically prepared by deformation heat treatment process, that is, "solution → processing → aging" process, in which solution treatment is annealed at a higher temperature for a long time, and there are the following problems: 1) The heating temperature is high (above 400°C), long holding time (depending on the batch size in the furnace, usually several hours), and high energy consumption; 2) Surface oxide layer is easy to form during heat treatment, which is difficult to remove in subsequent processes, affecting product quality; 3) It is easy to cause abnormal grain growth, resulting in coarse grains and uneven size distribution inside the alloy, which seriously damages the mechanical properties of the alloy; 4) The processing technology is demanding, and it is easy to cause uneven internal temperature of the material and local overburning, resulting in solid solution Poor uniformity, consistency and stability of alloy structure and properties after treatment

In addition, the magnesium alloy after solution treatment undergoes plastic forming and aging treatment, and the aging temperature is generally lower than the recrystallization temperature. Although strengthening phases can be precipitated in the magnesium matrix to improve the strength of the alloy, the magnesium matrix crystals produced by solution treatment Coarse particles and uneven size distribution still exist, and the prepared alloy has poor plasticity and limited strengthening degree.

Images