Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7993352 | Journal of Alloys and Compounds | 2018 | 37 Pages |
Abstract
In the current study, parallel tubular channel angular pressing (PTCAP), as a severe plastic deformation (SPD) method, was applied on a commercial pre extruded Mg-3Al-1Zn (AZ31) alloy tubes at 300â¯Â°C to achieve a fine-grained (FG) structure. To study the deformation behavior, tensile testing at different temperatures of 25â¯Â°C, 350â¯Â°C, 400â¯Â°C, and 450â¯Â°C was done on the samples processed by multi-pass PTCAP. Also, the strain rate sensitivity exponent (m) is measured for the four-pass PTCAP processed tube, at 350â¯Â°C, 400â¯Â°C and 450â¯Â°C and strain rates of 10â2, 10â3 and 10â4 1/s. The average value of m coefficients was â¼0.3. A higher elongation to failure of â¼281% was achieved at a higher temperature of 450â¯Â°C and a lower strain rate of 10â4 1/s, due to grain boundary sliding as a dominant deformation mechanism. After the first pass of PTCAP a bimodal microstructure, with large gains surrounded by many small ones, was observed. The grain refinement and homogeneity of the microstructure was enhanced by applying subsequent passes of PTCAP. Vickers microhardness measurements show that by more grain refinement caused by applying for more PTCAP passes, the value of hardness increased. Fractographic SEM images revealed that predominately ductile fracture occurred in all evaluated samples.
Related Topics
Physical Sciences and Engineering
Materials Science
Metals and Alloys
Authors
M. Eftekhari, A. Fata, G. Faraji, M.M. Mashhadi,