2023 Volume 41 Issue 3 Pages 242-247
A growth rate of an intermetallic compound (IMC) composed of Fe and Al was evaluated to predict the distribution of IMC at the Fe/Al dissimilar material interface during laser brazing. A carbon steel crucible was made, then the aluminum alloy of braze material was melted in the crucible, and the IMC thickness formed at the Fe/Al solid-liquid interface was measured at heating temperatures between 750~900 ºC. EDS analysis revealed that the IMC at the interface was FeAl3 or Fe2Al5, the IMC growth follows a parabolic law, and the growth rate constants obtained at each temperature were evaluated using the Arrhenius equation to clarify the temperature dependence of the growth rate. The temperature history at the Fe/Al interface was extrapolated by measuring the temperature history inside the carbon steel plate during laser brazing. The IMC thickness was calculated by combining the extrapolated temperature history and the IMC growth rate equation. The calculated IMC thickness agreed with the actual IMC thickness formed at the Fe/Al interface. Therefore, the validity of the IMC growth rate of carbon steel and aluminum alloy was verified.
