Influence of β Precipitated Phase on Mechanical Properties of Equal Channel Angular Pressing-Processed WE43 Alloy

Solution-treated samples are processed using ECAP at 300 C-degrees up to four passes (1P-4P) applying route Bc to improve mechanical properties and corrosion resistance of WE43 magnesium alloy. Results show that the yield strength (YS) and uniaxial tensile strength (UTS) continue to improve up to 3P. In addition, the ultimate strain also improves up to 2P. All these properties, however, deteriorate in 4P. The improved YS and UTS are attributed to the pinning effect of the precipitated intermetallic secondary phase of beta particles with Mg5RE composition, while morphology changes are found to be responsible for the decline in the properties. In other words, needle-like Mg5RE in 1P and 2P samples was broken to spherical in 3P and enlarged in 4P samples which acted as crack nucleation sites. The dynamic recovery is deduced by the occurrence of equiaxed grains along elongated ECAPed one whose role in lowering grain size is verified by a decrease in dislocation density in fourth pass.

Automated summary

The mechanical properties and corrosion resistance of WE43 magnesium alloy are improved by processing samples using ECAP up to four passes. Yield strength and uniaxial tensile strength continue to improve up to three passes, but deteriorate in the fourth pass. The improvement in properties is attributed to the pinning effect of the precipitated intermetallic secondary phase of beta particles, while the decline in properties is associated with morphology changes.