The quench sensitivity of 6063 alloy was investigated via constructing time-temperature-property（TTP） curves by interrupted quenching technique and transmission electron microscopy（TEM） analysis.The results show that the quench sensitivity of 6063 alloy is lower than that of 6061 or 6082 alloy,and the critical temperature ranges from 300 to 410℃ with the nose temperature of about 360℃.From TEM analysis,heterogeneous precipitate β-Mg2Si is prior to nucleate on the（AlxFeySiz） dispersoids in the critical temperature range,and grows up most rapidly at the nose temperature of 360℃.The heterogeneous precipitation leads to a low concentration of solute,which consequently reduces the amount of the strengthening phase β＇＇ after aging.In the large-scale industrial production of 6063 alloy,the cooling rate during quenching should be enhanced as high as possible in the quenching sensitive temperature range（410-300℃） to suppress the heterogeneous precipitation to get optimal mechanical properties,and it should be slowed down properly from the solution temperature to 410℃ and below 300℃ to reduce the residual stress.
The effects of heat treatment on the microstructure and mechanical properties of ZA27 alloy were studied by X-ray diffraction（XRD）,scanning electron microscopy（SEM） and mechanical characterization.The results indicated that the as-cast microstructure of the alloy was mainly composed of α,decomposed β,η and ε phases.After solid solution treatment at 365 ℃ for 1 h,α and η phases dissolved,and the microstructure of specimen was mainly composed of the supersaturated β phases.The phase decomposition of supersaturated ZA27 alloy is a two-stage phase transformation：the decomposition of the supersaturated β phase at the early stage of aging,and with the increase of aging time,ε phase decomposition through a four-phase transformation：α＋ε→T ＇＋ η.A good combination of high tensile elongation and reasonable strength can be achieved by suitable heat treatments.
The analysis of variance(ANOVA), multiple quadratic regression and radial basis function artificial neural network(RBFANN) methods were used to study the springback and tensile strength in age forming of 2A97 aluminum alloy based on orthogonal array. The ANOVA analysis indicates that the springback reaches the minimum value when age forming is performed at 210 °C for 20 h using a single-curvature die with a radius of 400 mm, and the tensile strength reaches the maximum value when age forming is performed at 180 °C for 15 h using a single-curvature die with a radius of 1000 mm. The orders of the importance for the three factors of pre-deformation radius, aging temperature and aging time on the springback and tensile strength were determined. By analyzing the predicted results of the multiple quadratic regression and RBFANN methods, the prediction accuracy of the RBFANN model is higher than that of the regression model.
