Hardness homogeneity and micro-tensile behavior in a magnesium AZ31 alloy processed by equal-channel angular pressing

A magnesium AZ31 alloy was processed by equal-channel angular pressing (ECAP) at a temperature of 473 K using a die with a channel angle of 110°. The results show that an ultrafine-grained (UFG) microstructure is achieved with good hardness homogeneity after processing through 4 or more passes of ECAP. After 8 passes of ECAP, a grain size of ~1.0 ?m was achieved. Measurements show that the average value of the microhardness increases with increasing numbers of ECAP passes. The mechanical properties were evaluated using micro-tensile testing with specimens cut perpendicular to the longitudinal axes of the ECAP billets. These tests were conducted at room temperature and at 423 and 473 K and the results demonstrate a potential for using the UFG AZ31 alloy for applications in micro-forming technology

Microhardness, microstructure and tensile behavior of an AZ31 magnesium alloy processed by high-pressure torsion

An AZ31 magnesium alloy was processed by high-pressure torsion (HPT) at room temperature under an imposed pressure of 6.0 GPa. Microstructural analysis showed that the HPT processing introduced significant grain refinement with a reduction in grain size from ~35 ?m in the initial annealed condition to ~110 nm after ten turns of HPT. Microhardness measurements showed that a reasonable level of hardness homogeneity was achieved across the disk processed through ten turns. The results from tensile testing demonstrated that the ultrafine-grained (UFG) AZ31 alloy processed by HPT exhibits high ductility with a maximum elongation of ~400 % at the relatively low testing temperature of 423 K. The results confirm that the UFG AZ31 magnesium alloy processed by HPT through ten turns has a strong potential for use in micro-forming applications

Dry sliding wear of an AZ31 magnesium alloy processed by equal-channel angular pressing

A magnesium AZ31 alloy was processed by equal-channel angular pressing (ECAP) for up to 8 passes to reduce the grain size to ~1.0 ?m. Following ECAP, microhardness measurements were taken to evaluate the mechanical properties of the material. Ball-on-disc dry sliding tests were conducted to compare the wear behaviour of the as-received alloy and the alloy processed by ECAP. The surface topography and volume loss were recorded for all samples. The results show that the fluctuations and average values of the coefficient of friction are improved after processing by ECAP. In addition, there is a decrease in the wear depth and volume loss with increasing numbers of ECAP passes. The ECAP-processed alloy has a higher wear resistance than the unprocessed alloy and it is a suitable candidate material for use in industrial application