The effect of ternary alloying additions on solute-drag creep in aluminum-magnesium alloys

Solute-drag creep is observed in many aluminum alloys containing magnesium concentrations from as little as 2 wt pet to the limit of solubility. Detailed studies of this behavior in low-impurity, binary Al-Mg alloys are available in the literature, and established models have been successful in predicting observed behavior. Solute-drag creep in more complex Al-Mg materials containing ternary alloying additions has received less study, yet is of practical significance because of the enhanced ductility which it affords. Tensile ductilities in excess of 100% can be repeatedly achieved in commercial Al-Mg alloys deformed under solute-drag creep. Recent investigations have produced data from commercial alloys as well as low-impurity, ternary Al-Mg alloys containing Mn, Fe, and Zn additions. This article compares stress-exponent data from these material with data from binary AI-Mg alloys and pure Al. The effects of ternary alloying additions are analyzed for application to the design of future commercial alloys.