I have some findings in solid-state extrusion of Mg wire from machining chips by Friction Stir Extrusion, but it’s kind of against my previous impressions on this topic. Can you help me to clarify it?
What I learned before is, the twinning usually occurs at low temperature and fairly early stage of a plastic deformation process, i.e. the plastic strain is still fairly low. As long as the temperature or plastic strain keeps increasing, new sub-grains will form in the twinning lamellas, so that they will be resolved as the process going. In my present study, both of the temperature (450-500 C) and plastic strain should be high. However, we still have these twinning lamellas.
If they were formed at the early stage of the experiments, how did they survive?
If they were formed after the wire was formed, what the mechanism that they can form? And when they were formed, e.g. during cooling?
Dear Reza Abdi Behnagh
the occurrence of twinning frequently have been reported during SPD of Mg alloys such as ECAP, HPT and ABE processes. this phenomena is related two complex state of deformation during spd process. ....in the case of twinning , we have 3 kind of twin in Mg alloys including tensile twin, compression twin and double twin among them tensile twinning will active in early stage of deformation.....it has been reported that for example compression twinning occurred in final stage of deformation and is responsible for fracture in mg alloys.
Interesting results, same with me.
But the temperature I get them is about 400℃, alloys heavily alloyed with many other elements.
Still working on reasons about it.
Good luck, maybe there are something common in both our results.
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