|About this Abstract
||2016 TMS Annual Meeting & Exhibition
||Aluminum Alloys, Processing and Characterization
||Precipitation of Al3Zr Dispersoids during Homogenization of Al-Zn-Cu-Mg-Zr Alloys
||Pikee Priya, Matthew J. M. Krane, David R Johnson
|On-Site Speaker (Planned)
Dispersoids of Al3Zr in Al-Zn-Cu-Mg-Zr alloys are important as they pin grain boundaries and inhibit recrystallization during extrusion and solution heat treatment of these alloys. A high volume fraction, VAl3Zr and low radius, rAl3Zr leading to VAl3Zr / rAl3Zr values above a critical value is essential to prevent recrystallization. Precipitation of Al3Zr during homogenization is studied for different homogenization schedules. A 1D finite difference model based on classical nucleation and growth theory for a multi-component system is developed to simulate precipitation of Al3Zr dispersoids. A 1D-domain representing one half of a Secondary Dendrite Arm Spacing with concentration gradients based on Scheil type solidification is used. Single-step homogenization, multi-step homogenization and slow heating to homogenization temperatures are evaluated for maximum number density, maximum volume fraction and minimum dispersoid radius. Length of the dispersoid free zone is also calculated for each of the schedules. An optimum homogenization schedule based on the study is proposed.
||Planned: Light Metals Volume