The Influence of Alloy Composition and Thermo-Mechanical Processing Procedure on Microstructure and Mechanical Properties of High-Magnesium Alloys

摘要

The purpose of this research was the development of a thermomechanical procedure to process Aluminum-Magnesium alloys and testing effects of alloying additions on these alloys. Magnesium contents of eight and ten weight percent and the alloying effects of copper and manganese were studied. Microstructures and mechanical properties at six warm rolling temperatures located above and below the solvus line of these alloys were examined. Ultimate tensile strengths in excess of 680 MPa (99 KSI) were obtained. Microstructural evidence indicated that the precipitation of the 'beta' intermetallic phase was one of the most important mechanisms in controlling the strength of the alloy. Furthermore, precipitation is so rapid at higher temperatures that it becomes the strongest force within the microstructure and its presence prevents any possible recrystallization of the alloy. However, when the temperature exceeds the solvus temperature for the alloy, recrystallization does occur with large losses in both yield and ultimate tensile strength. (Author)