Evaluation of Hot Tensile Behavior of Fine-Grained Mg-9Al-1Zn Alloy Tube Processed by Severe Plastic Deformation

摘要

In the present study, parallel tubular channel angular pressing (PTCAP) process was implemented to as cast Mg-9Al-1Zn magnesium alloy tubes via different number of passes at 300 A degrees C. Mechanical properties and microstructure evolution of the tubes were investigated at room and elevated temperatures. The results showed that an increase in strain leads to a higher strength, hardness, and elongation at room temperature. A significant grain refinement was achieved. It was decreased to 4 A mu m for a third pass processed tube from an initial value of 150 A mu m. Strength increased notably to about 92 % after the second pass PTCAP process. Increase in the strength after first pass PTCAP was 56 %. Elongation relatively increased at room temperature, too. Microvoids and microcracks appeared in the third pass processed specimen. This led to a loss in strength and elongation in comparison with first and second pass processed samples. Two pass processed sample revealed similar to 178 % ductility in 400 A degrees C tensile test. Hardness increased by about 77 % after third pass PTCAP process. The result of the mechanical properties and the microstructure were consistent with each other.