Abstract
The kinetics of the interface reaction at the early stage of alloy growth in tinplate has been investigated below and above the melting point of tin, and a theory has been developed to determine the reaction time between iron and tin. This time defines the first stage of alloy growth during which the FeSn2 nuclei grow laterally and cover the iron/tin interface with an extremely thin reaction alloy layer. An analytical formula has been obtained for calculating the reaction time as a function of the heating temperature, and the reaction time was also determined experimentally. The results obtained by both methods show very good agreement. The activation energy for FeSn2 formation was determined as a separate term of energy, contributing to the activation energy for diffusion controlled growth. Close values were obtained in both cases below and above the melting point of tin. Determination of the reaction time allows the prediction of the actual duration of the reflowing period and hence the growth of the alloy layer can be accurately controlled.
MST/426