Anelastic Behaviour of Commercial Die-Cast Magnesium Alloys: Effect of Temperature and Alloy Composition

The anelastic deformation, resulting from partial reversal of {101¯2} twinning, is studied at room temperature to 150 °C on several commercial die-cast magnesium alloys for the first time. The magnitude of anelastic strain decreases with increasing temperature. For inter-alloy comparison, AZ91 shows the largest maximum anelastic strain, while AM40 and AM60 show similar maximum anelastic strain. The phenomenon is discussed in terms of solid solution softening and hardening of slip planes and how they influence twinning. T5-aged AE44 consistently shows smaller magnitude of anelasticity compared to as-cast AE44, suggesting that the precipitates formed during ageing may decrease the twin-boundary mobility and further suppress untwinning. Presence of anelasticity poses a challenge to yield strength measurement using the conventional 0.2% offset method, and a more accurate and consistent method of using a higher offset strain or a lower modulus is proposed in this study.

TRENDS IN THE DEVELOPMENT OF CAST MAGNESIUM ALLOYS WITH AN INCREASED IGNITION TEMPERATURE (review)

Trends in the development of cast magnesium alloys with increased temperature, ignition and fire resistance are presented. The main world companies and institutions - developers of casting magnesium alloys are presented. The developed alloys are considered, indicating their chemical characteristics, mechanical characteristics at high and high temperatures and corrosion resistance, as well as the use of materials and design aspects of industry. The presented magnesium alloys with an increased ignition temperature allow expanding the scope of their use.

A Minuscule Appraise on the Outcome of BI and SB Metallic Additives on Refining the Microstructure and Mechanical Behavior of few Magnesium Alloys

This paper reviews the outcome of bismuth and antimony trappings on the microstructure and mechanical behavior of an assortment of commercial magnesium alloys. Various compositions of the Bi and Sb were discussed along with/without combination of other alloying elements. These additions have revealed to be resulted in the formation of Mg3Bi2 , Mg3Sb2 intermediate phases when added upon with corresponding alloying elements. Moreover the reasons for the observed changes due to the addition of these alloying elements were also reviewed. It is found that the accumulation of Bi phase as well as intermetallics and Sb intermediates has greatly improved the microstructure belonging to the as cast magnesium alloys thereby improving both mechanical and thermo-mechanical properties. It is also observed in the review that addition of thesealloying elements acted as grain refiner and improved the corrosion resistance of commercial magnesium alloys.