The Valence Electron Research On The Mechanism Of Ageing Strengthening In Al-Mg-Si Alloy

Based on the Yu's EET and Cheng's improved TFD theory and used the calculation methods of alloying valence electron theory, the valence electron structures of phases and phase interfaces of supersaturated solid solution GP-zone and stable phase Mg₂Si are calculated in ageing strengthening of Al-Mg-Si alloy. The reason that supersaturated solid solution immediately transforms into GP-zone after artificial aging at low temperature is analyzed by phase structure factor and phase interface combination factor of the supersaturated solid solution and the GP-zone. The essence that the supersaturated solid solution directly forms GP-zone but not the stable phase Mg₂Si is disclosed by the valence electron structures of the stable phase and GP-zone in Al-Mg-Si alloy. The impact of Mg₂Si on the nature of Al-Mg-Si alloy is discussed by the phase interface valence electron structure of Mg₂Si. In addition, the valence electron structure of transitional phaseβ′is tried to calculate, and the cause that the valence electron structures ofβ′are unsuccessfully calculated is analyzed. Simultaneously the phase and phase interface valence electron structures ofβ′are forecasted, and it gives foundation for other researchists to research further. Therefore, by the researches on the ageing strengthening of Al-Mg-Si alloy, the new viewpoint and the new method are advanced at the electron structure level to discuss the ageing strengthening behaviors of Al-Mg-Si alloy.