Method for simultaneously improving strength and plasticity of copper aluminum alloy

Abstract

The invention provides a method for simultaneously improving the strength and plasticity of copper aluminum alloy, and belongs to the technical field of material processing. The method comprises the following steps: mixing pure copper and pure aluminum according to a proportion, carrying out vacuum induction melting, and pouring to form a copper aluminum alloy plate; heating the plate at 850-900 DEG C, and insulating for 1-2 hours; then, carrying out hot rolling on the plate for three passes, and then annealing in vacuum at 750-800 DEG C for 3-4 hours, wherein the thickness of the plate after processing and heat treatment is 7.9-8.9mm; immersing the copper aluminum plate in liquid nitrogen to cool for 5-10 minutes, and carrying out cold rolling, wherein the strain capacity of the plate before and after rolling is 92-98 percent, the plate is immersed in the liquid nitrogen and cooled for 5-10 minutes before every pass of rolling, and the final thickness of the plate is 0.5-0.6mm; annealing the plate at a low temperature of 300-350 DEG C for 1-1.5 hours; carrying out surface mechanical attrition treatment (SMAT) on the plate in vacuum or liquid nitrogen. According to the method, the tensile strength of the prepared Cu-4.5%Al alloy in liquid nitrogen after SMAT is 583MPa, and the uniform elongation rate is 15.4 percent; and the prepared plate has excellent surface abrasion resistance, corrosion resistance and fatigue resistance.

Description

technical field [0001] The invention relates to a method for simultaneously improving the strength and plasticity of copper and aluminum alloys, and belongs to the technical field of material processing. Background technique [0002] Usually, the means of strengthening materials include solid solution strengthening, second phase strengthening, fine grain strengthening and dislocation strengthening, etc., the essence of which is to introduce various point, line and surface defects into the material to hinder the movement of dislocations so as to achieve the effect of strengthening the material. Purpose. Among all these strengthening mechanisms, fine-grain strengthening has attracted the attention of scientific researchers as the only method that can not only improve the strength of materials but also improve the plasticity. [0003] In the past few decades, nanomaterials have been widely studied because of their excellent mechanical properties. Compared with traditional ...

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Problems solved by technology

[0004] After the material is made into nanometer size through the large plastic deformation process, although the strength has been greatly improved, the plasticity is often poor, and the elongation at break is often less than 5%, which limits the application field of nanomaterials.

[0006] However, through the surface mechanical grinding treatment process (SMAT), the improvement of material strength is very limited

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