Diffusivity of Al and Fe near the diffusion bonding interface of Fe 3Al with low carbon steel

Abstract

The distribution of elements near the Fe3Al/Q235 diffusion bonding interface was computed by the diffusion equation as well as measured by means of EPMA. The results indicated close agreement between the two for iron and aluminium. Diffusion coefficient in the interface transition zone is larger than that in the Fe3Al and Q235 steel at the same temperature, which is favourable to elemental diffusion. The diffusion distance near the Fe 3Al/Q235 interface increased with increasing heating temperature, T, and the holding time, t. The relation between the width of the interface transition zone, x, and the holding time, t, conformed to parabolic growth law: x2 = 4.8 × 104 exp(- 133/RT) (t - t0). The width of the interface transition zone does not increase significantly for holding times beyond 60 min.