Kinetics of solid-state reactive diffusion between co and sn

Abstract

To examine growth behavior of i-CoSn3 at solid-state temperatures, kinetics of reactive diffusion between Co and Sn was experimentally observed using sandwich Sn/Co/Sn diffusion couples prepared by a diffusion bonding technique. The diffusion couples were isothermally annealed in the temperature range of 433473K for various times up to 744 h. Owing to annealing, an intermetallic layer consisting of CoSn3 was formed at the original interface in the diffusion couple. The mean thickness of the intermetallic layer increases in proportion to a power function of the annealing time. The exponent of the power function takes values of 0.67 and 0.62 at 433453 and 473 K, respectively. These values of the exponent indicate that volume diffusion predominantly controls the layer growth and interface reaction partially contributes to the rate-controlling process. © 2014 The Japanese Society for Non-Destructive Inspection.