THE INFLUENCE OF ALLOYING ELEMENTS AND HEAT TREATMENT UPON THE PROPERTIES OF ELEKTRON 21 (EV31A) ALLOY

摘要

Elektron 21 (ASTM Designation EV31A) is a Mg-RE-Zn-Zr alloy designed for Aerospace and Speciality Applications. The alloy is capable of operating up to approximately 200℃ (400℉). To achieve successful applications, Elektron 21 has had to exhibit not only good mechanical properties but also good corrosion performance and ease of castability. When developing the alloy, the effect of the Rare Earth (RE) constituents and Zinc were optimised to achieve these requisite alloy characteristics. Changes in the Rare Earth and Zinc content affect age hardening response. Control of individual Rare Earth components also influences castability. The level of Rare Earth component and, more importantly Zinc content, must be limited and controlled to achieve good and consistent corrosion performance. Finally, the effects of heat treatment variables were assessed in relation to corrosion performance.