Study of Differential Scanning Calorimetry on Phase Precipitation in Various Heat Treatments of AlZnMgCu Aluminum Alloys

Abstract

Powers compensation of the differential scanning calorimetry (DSC) have been utilized to revealed and analyze the phases of precipitations in the complex quaternary of Zinc (6.7wt. %) _ Magnesium (2.8 wt. %) _ Copper (1.8 wt. %) _Aluminum alloys manufactured by the process of the Semi-Direct Chill Casting. The casted Al-Zn-Mg-Cu alloys slabs were homogenizing at the different temperatures. Firstly under treatment 450°C for 2 hours follow by treatment 470°C for 1 day and then treatment at 480°C for 40 minutes, then all casted samples have quenched in cold water after each step. The treated homogenized Al-Zn-Mg-Cu samples that were underwent the artificial ageing at 120 °C for 1 day, and then retrogression at 180°C for 2400sec. and then reageing at 120°C for 1 day. The outcomes proved that the X-ray diffraction (XRD) analyses confirmed information of the DSC thermal analyses which were obtained through various heat treatments of the three samples AlZnMgCu alloy. The outcomes have explained that the DSC data are helping in understanding the changes the peaks of temperatures as well the enthalpy values for the forming and dissolution the equilibrium phase’s and precipitation compounds within the artificial againg (with the pea-temper) and the Retrograession and Re-Againg-(RRA) treatments were conducting for Al_Zn_Mg_Cu alloy samples.