Abstract:

In this work, the Mg-5Al-2Ca alloy was extruded at 573, 623 and 673 K, with a ratio of 16:1 and a constant speed of 3 mm/s. Results demonstrate that the Al₂Ca particle is formed in Mg-5Al-2Ca alloy. The size, amount and distribution of Al₂Ca particles are influenced evidently by extrusion temperature. Unlike previous reports, the intensity of basal texture increases with increasing extrusion temperature, and the reasons are analyzed and given. Even though the average grain size increases as the extrusion temperature increased from 573 to 623 K, the YS, UTS and elongation of as-extruded Mg-5Al-2Ca alloy are almost kept the same at 573 and 623 K. The reason is speculated as the balance of grain size, Al₂Ca phase and texture at the two temperatures. The work hardening rate depends on extrusion temperature, and the largest θ value of Mg-5Al-2Ca alloy is obtained when the extrusion was performed at 623 K.

Key words: Mg-Al-Ca alloy, Extrusion, Microstructure, Mechanical properties, Work hardening