Transient liquid phase bonding process using liquid phase sintered alloy as an interlayer material

An attempt was made of using a liquid phase sintered alloy, which will be a liquid phase coexisting with solid particles at the bonding temperature, as an interlayer for bonding metals. With an aim of revealing the fundamental features of this modified TLP bonding, investigated were the kinetics concerned with the isothermal solidification process and the growth of solid particles in Fe-4.5wt%P and Fe-1.16wt%B interlayers for bonding pure iron. The movement of the bond interface was linearly dependent on t1/2 with higher slope than expected in the normal TLP bonding. The higher slope is attributed to the contribution of the solid particles distributed in the interlayer. The solid particles have shown no growth. However, when pure Fe particles are allowed to coexist with the liquid of equilibrium composition, they grows very rapidly. Discussion was made on the growth kinetics of the pure Fe particles.