An Investigation into the Influence of Thermomechanical Processing on Microstructure and Mechanical Properties of High-Strength Aluminum-Magnesium Alloys

摘要

Microstructures and mechanical properties resulting from thermomechanical processing of high-Magnesium (Mg) content Aluminum-Magnesium (Al-Mg) alloys were investigated in this research. Warm rolling processes, intended to refine both grain size and second phase Al3Mg2 (beta) particle size, were conducted for alloy compositions of 10.2 weight % Mg, 10.2 weight % Mg plus 0.5 weight % copper (Cu) and 12.1 weight % Mg. Solution treatment, hot upset forging, resolutioning and rapid cooling provided initial microstructural homogenization. Subsequent warm rolling was employed to refine the microstructure. The effect of warm rolling parameters of beta particle size and distribution was of particular concern. By warm rolling an alloy containing 10.2 % Mg plus 0.5 % Cu at 250 C, an ultimate tensile strength of 565 MPa (82000 psi), with 11.5 % elongation, was achieved with the added advantage of a strength to density ratio higher than present equivalent-strength alloys, such as 7075-T6.