Research On Deformation Mechanism Of Pure Zr With Uniaxial Texture Rolled At Different Temperatures

With the wide application of zirconium and zirconium alloys in nuclear industry,the materials of construction made by zirconium should be provided not only excellentcorrosion resistance, but also need to have good mechanical properties. Therefore, toacquire the deformation behavior, structure and texture evolutions of zirconium, it needsto do further research about deformation mechanism.In this paper, the pure zirconium was rolled uniformly at different temperatures,and we got samples reduced to5%-50%at low temperature and room temperature.According to the tools such as optical microscopy, scanning electron microscopy,transmission electron microscopy, micro-hardness tester, universal tensile machine andXRD, the deformation structure, texture, and mechanical performance of differentspecimen were tested. Then, combining with the software and procedure, theexperiment results were analyzed and fitted. Finally, we got the information aboutdeformation mechanism.The results showed that the as-received pure zirconium was annealed withconcentrated basal pole figure and the grains were equiaxed in the size about30μm.After rolling paralleled to the c-axis, the number of twins in samples rolled at lowtemperature increased with the reduction increasing, and it is able to generate varioustypes of twinning. Conversely, the ones rolled at room temperature had few twins, andthe deformation was dominated by slip.In the research about the rolling structure evolution, it was found that the basaltexture was changed a lot to bimodal texture at low temperature rolling since the twinsand slips modes. But the samples rolled at room temperature got a more concentratedbasal pole figure. Because of the different deformation modes, the mechanicalproperties of the materials deformed at two temperatures respectively performeddisparate experiment results.In addition, the Schmid factor got through the software revealed that the nucleationof twinning depends on the orientation of grains. By summarizing the results ofexperiment, the deformation mechanism rolled at low temperature is thatslip→{1122}<1123>C1twinning→{1012}<1011>T1secondtwinning→{1121}<1126>T2twinning→slip while rolled at room temperature isdominated by slip coordinated by fewer {1121}<1126>T2twinning which is aimed at adjusting the grain orientation and relaxing the concentrated stress.