Electron Structure and Interphase Boundary Energy of GP Zone in Al-Zn Alloy

The valence electron structure of GP zone in Al-Zn alloy is calculated according to the empirical electron theory. The result of valence electron structure is further applied to analyzing the interphase boundary energy between GP zone and matrix. The GP zones are formed even at the highest quenching speed, and the hardness is stably ascended as soon as GP zones are formed and reached the maximum before the form of metastable phase, because the number of the strongest covalent bond in GP zones is far more than that in α-Al cell and Al atom is easily prone to forming covalent bond with Zn atom. It is an easy and effective method to apply EET theory to the calculation of interphase boundary energy.