On the Non-isothermal Precipitation of the and b phases in Al-12.6 mass% Mg alloys using dilatometric techniques

The non-isothermal kinetics of precipitation of an Al-12.6 mass% Mg alloy for different heating rates were studied using thermal expansion techniques. The structural changes associated with the precipitation of the and b phases were identified. The conversion degree of each phase was associated with the area under the derivative curve of the thermal expansion with respect to temperature. Using the Kissinger relation and an iso-conversional method we calculated the apparent activation energies associated with formation of the precipitated phases. We report an increasing dependence of the activation energy on the conversion degree, the values obtained being within the range reported in the literature.