The research of Strengthening mechanisms of 7085 aluminum alloy by solution-large-deformation

Abstract:

Experimental object of this paper is the solution-aging and solution-large deformation (compression,ECAP)-aging of 7085 aluminum alloy. Through the tensile testing machine and scanning electron microscope (SEM) to test the tensile properties and fracture analysis. Internal dislocation density, low angle grain boundary and high angle grain boundary of 7085 aluminum alloy under different states were characterized through X-ray diffractometer (XRD) and Electron Back Scattering Diffraction (EBSD) .Combined tensile test measured yield strength, strengthen the contribution of the large deformation strengthening aluminum items of the quantitative calculation.The results show that, compared with conventional solution-aging treatment, the solution-large deformation - aging treatment can significantly refine grain size, increase the number of low angle grain boundary, prompt uniform distribution of precipitated phase so as to advance yield stress. Especially, Equal Channel Angular Pressing (ECAP) is more effective than compression in improving overall performance. Large deformation processing of 7085 aluminum alloy also makes a lot of internal accumulation of dislocations, large deformation processing was improving performance mainly depends on the alloy dislocation strengthening and small-angle grain boundary strengthening, alloy internal solid solution strengthening and second phase strengthening has been weakened by large deformation processed.