Improving room-temperature stretch formability of a high-alloyed Mg–Al–Ca–Mn alloy sheet by a high-temperature solution-treatment

Various solution-treatments were applied on a rapidly solidified and subsequently rolled Mg-7.50Al-1.07Ca-0.17Mn (mass%) alloy sheet, room-temperature stretch formability, tensile properties, microstructures, textures of the solution-treated sheets have been investigated. Although solution-treatment at 400 °C gives high strengths, sheet shows poor formability with Index Erichsen value 4.8 mm due to densely dispersed second phase particles. Also, particles tend distribute rolling direction, leading limited elongation failure 11.0% along transverse direction. The higher temperature leads sparse relatively uniform dispersion This results in significant improvement ductility. increases 6.8 by 450 for 4 h, large 19.1% 17.1% directions, respectively. also exhibits strengths in-plane isotropic strength over 320 MPa 0.2% proof stress ~180 could be obtained fine grain structure average size 9.5 ?m.