Investigation of the effect of B-Mg۱۷Al۱۲ Precipitate morphology on mechanical properties of a fine-grained AZ۸۰ Magnesium Alloy

Magnesium alloys are emerging as technological materials with various new potential applications; also, a good combination of mechanical properties and corrosion performance is considered. The mechanical properties of magnesium alloys are greatly influenced by the morphology, distribution, and volume fraction of secondary phases and grain size. Decreasing grain size after homogenization, ۱۰% cold rolling was performed. Then, samples have aged at different temperatures (۱۷۵°C, ۲۷۰ °C, and ۳۵۰ °C) and time (chosen based on aging curves) to achieve the various morphology of the Mg۱۷Al۱۲ precipitates. The morphologies of the discontinuous precipitates (DP) and continuous precipitates (CP) were controlled by changing the aging-treatment conditions. Optical microscopy, scanning electron microscopy techniques were used to study the microstructure and morphology of Mg۱۷Al۱۲ precipitate. Also, tensile test and Vickers hardness test were performed to investigate the effect of the beta phase's morphology on mechanical properties, and the values of UTS, Ys, and elongation to failure parameters for the sample aged at ۲۷۰°C were measured to ۴۷۸ MPa, ۳۶۰ MPa and ۱۲.۳%, respectively. The grain refinement and the increase of twinning deformation during cold rolling and the formation of β precipitation in the form of CP + DP due to aging at ۲۷۰ C caused improved strength in this sample.

کلیدواژه ها:

Magnesium alloy ، Aging-treatment ، Mg۱۷Al۱۲ precipitates ، Mechanical properties.