Large Deformation Asynchronous Stack Rolling Preparation Of Ultrafine Grain Copper, Organizations And Texture Evolution Studies

Nowadays, we nearly reached the end to the understanding and use of the traditional metal materials, but the deep development of modern industry constantly needs for higher performance to the metal materials ,We must make deeper exploiture to the performance of the metal materials ,that is using the texture to obtain further improvement on the basis of materials' performance originally, for example: High purity Al foils are used for the anode materials of high voltage electrolytic capacitors. The stronger the cube texture in Al foils is, the higher content of specific capacitance is. So, it is very important to research the texture of materials.In this paper, the copper sheets were subject to asymmetrical accumulative rolling-bonding (AARB) by different passes and recrystallization annealing. The microstructures of samples were observed with optical microscope, scan electron microscope and transmission electron microscope, the X-ray and electron back scattering diffraction(EBSD) texture analyses were performed for various samples. Based on the experimental results, discussing the characteristics of microstructures and how the texture is formed in the condition of different technological parameters, and the formation mechanism of the recrystallization texture was analyzed and discussed.The experimental results showed that:In the process of AARB, the crystalline grains were elongated gradually and fibrosed or were disintegrated. The more the passes were, the thinner the fibrous structures were, the more disintegrable degree was. And there was the sub-structure in the crystalline grain.For the cold rolled samples, they were characteristics of the so-called copper-type textures, i.e. the most significant aspect of the texture are the strengthening of the C-{ 11 2}<111 > , S-{ 1 23 }<634>, B-{110}<112> components. With the increases of the passes, the texture components intensified gradually and the C-{112}<111> component became dominant.With annealing at 130°C for 30min, the samples didn't have obvious change in the macrostructure. The cold-rolling texture has been kept, butthe intensity was weakened, and faint R-{112}<111> texture component was found.With annealing at 220°C for 35min, the equiaxed grains with grain size between 100 to 200nm were obtained, the recrystallization is finished basically. The recrystallization texture were constituted of R and C components mainly, but the cube texture was little content.