Hardening and precipitation behavior of as-quenched Al-0.4Mg-1.0Si alloy with minor Sn addition at different aging temperatures

摘要

The effect of Sn on the hardening and corresponding precipitation behavior of as-quenched Al-0.4Mg-1.0Si alloy at different aging temperatures was investigated with hardness tests, differential scanning calorimetry analysis, and transmission electron microscopy. The hardness of the Sn-free alloy was higher than that of the Sn-added alloys during under-aging, but the tendency is reversed during over-aging. The effect of Sn on the hardening behavior of these alloys is not substantially affected by the aging temperature, i.e., the addition of Sn can improve resistance to over-aging softening at different aging temperatures. The reason for the resistance to over-aging softening by the addition of Sn is related to the increase in the number density of precipitates during under-aging and the decrease in precipitates size during over-aging.

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