A novel method using differential scanning calorimetry was developed to quantify the interface kinetics in a solid/liquid diffusion couple. The Ag–Cu binary eutectic system was investigated by heating an assembly of Ag base metal and Ag–Cu eutectic foil to 800C and holding. The fraction of liquid remaining after various isothermal hold periods was measured by comparing the melting endotherms with the solidification exotherms. Detailed analysis of the results show the per cent liquid remaining was inversely proportional to the square root of isothermal hold time; however, effects of the base metal cause an apparent loss of 25% of the liquid immediately after heating. The fundamental understanding of the effects of bi-phase diffusion couple geometry was advanced to manifest the mechanisms resulting in the error. Further carefully devised experiments revealed that primary solidification during cooling was not included in the enthalpy of solidification measured by the differential scanning calorimetry. Furthermore, baseline shift across the melting endotherm increased the measured melting enthalpy. These effects combine to systematically underestimate the fraction of liquid remaining. Development of a modified temperature program and application of an appropriate correction could remedy these effects. The experimental results compare well with a prediction generated by an analytical model. Successful quantification of these phenomena has broadened the knowledge of differential scanning calorimetry operational characteristics in the solid/liquid diffusion couple treatment, which could now be applied to other material systems.

Quantifying Metallurgical Interactions in Solid/Liquid Diffusion Couples using Differential Scanning Calorimetry. M.L.Kuntz, S.F.Corbin, Y.Zhou: Acta Materialia, 2005, 53[10], 3071-82