Establishment of continuous cooling transformation diagrams of aluminum alloys using in situ voltage measurement

An effective method was proposed to establish the continuous cooling transformation (CCT) diagrams of aluminum alloys using in situ voltage measurement. The voltage change of samples with predefined dimension was recorded under the constant current state during continuous cooling. Solutionizing time, together with starting and finishing temperatures of phase transformation of the alloy can be obtained from relationships of voltage vs time and temperature. A critical cooling rate without detectable phase transition during continuous cooling can be determined. Continuous cooling transformation diagrams of tested samples can be established conveniently based on these results. Microstructure observation and differential scanning calorimetry (DSC) testing were applied to verify the reliability of continuous cooling transformation diagram.