Development of a Continuous Cooling Transformation Diagram for an Al-Zn-Mg Alloy Using Dilatometry
To develop CCT diagram using DSC requires the use of multiple devices in order to measure across the range of cooling rates required to develop the diagram. In the current work one dilatometer is used to characterize the precipitation reactions of the AA7020 alloy. Precipitation and dissolution reactions resulted in changes in the rate of change in the coefficient of thermal expansion. This was used to determine the start and finish temperatures of the MgZn2 precipitation reaction and produce the CCT diagram. Good agreement was found between the results of this technique and DSC results from the literature.
H.K. Chikwanda and S. Chikosha
M. Kumar et al., "Development of a Continuous Cooling Transformation Diagram for an Al-Zn-Mg Alloy Using Dilatometry", Materials Science Forum, Vols. 828-829, pp. 188-193, 2015