Study On Microstructure And Properties Of Fine Grain 2A12 Aluminum Alloy Prepared By High Pressure Torsion

As a typical process of Severe Plastic Deformation(SPD),High Pressure Torsion(HPT)is used in the plastic processing of many kinds of metal materials,which is a typical plastic processing method that can obtain fine-grained metal materials.Improving the comprehensive mechanical properties of metal materials by high-pressure torsion is one of the main research directions at present.The purpose of this paper is to propose a process for preparing fine-grained 2A12 aluminum alloy by high-pressure torsion.The samples of 2A12 aluminum alloy are treated by high-pressure torsion process with different deformation temperatures and torsion turns,and the distribution and variation law of equivalent strain of high-pressure torsion samples are studied by finite element simulation method,so as to clarify the effects of deformation temperature and torsion turns on microstructure,mechanical properties and fracture behavior.In this paper,Deform finite element software is used to simulate the high-pressure torsion process at Room Temperature(RT)with different pressures(0.64 GPa,0.8GPa and0.96GPa)and different torsion turns(1 turn,2 turns and 4 turns),to study the equivalent strain distribution and variation law of billet under different conditions,and to analyze the equivalent strain distribution law of high-pressure torsion deformed billet in axial and radial direction and surface layer and intermediate layer,and to clarify different pressures.The finite element numerical simulation of high-pressure torsion process at two deformation temperatures of 240? and 360? and different torsion turns(0.5 turns,1turn,2 turns and 4 turns)was carried out,and the effects of deformation temperature and torsion turns on the distribution and variation of equivalent strain of deformed blank were summarized.The results show that increasing the deformation temperature has a more obvious effect on increasing the deformation degree of billet than increasing the number of torsion turns,which provides guidance and reference for the selection of deformation temperature and torsion turns in high-pressure torsion experiment.Fine-grained 2A12 aluminum alloy samples were prepared by high-pressure torsion test at different temperatures(RT,120?,240? and 360?)and different torsion turns(0.5 turns,1 turn,2 turns and 4 turns).The macro-size,microstructure,tensile mechanical properties and fracture behavior of the samples before and after high-pressure torsion deformation were studied,and the effects of different deformation temperatures and different torsion turns on the microstructure and mechanical properties of the samples were revealed The results show that the tensile strength of HPT-RT/1t reaches the maximum value of 703.7MPa and the elongation of HPT-360?/1t reaches the maximum value of 35.5%.