Annealing Behaviors of Al and Al-Mg-Si Alloy: A Real-Time Synchrotron X-ray Scattering Study.

We have studied the annealing behaviors of pure Al (Al-1050) and Al-Mg-Si alloy (Al-6061) with plate-type using a real-time synchrotron X-ray scattering in vacuum. At room temperature (RT), the crystal domain size of Al phase in the Al-Mg-Si alloy was small as 70 nm, compared to that in the pure Al, 142 nm. The crystal Al phase in the Al-Mg-Si alloy has more thermal stability than that in the pure Al. The crystal Al phase in the Al-Mg-Si alloy was thermally stable in amount and size up to 250 °C. These are due to the existence of intermetallic crystal Mg₂Si phase, which is thermally stable in amount and size up to 250 °C.