Investigation on bonding strength of steel/aluminum clad sheet processed by horizontal twin-roll casting, annealing and cold rolling

Publication date: 15 December 2016
Source:Materials & Design, Volume 112
Author(s): G. Chen, J.T. Li, H.L. Yu, L.H. Su, G.M. Xu, J.S. Pan, T. You, G. Zhang, K.M. Sun, L.Z. He
In this work, a stainless steel/aluminum clad sheet was produced successfully by horizontal twin-roll casting. The interface morphology, element distribution and bonding strength of the clad sheets after different annealing and cold rolling processes were investigated using optical microscopy, electron probe micro-analyzer and T-type peel test. The surfaces of the steel and aluminum sheets after peeling were studied using scanning electron microscopy. In the as-cast clad sheet, a 3μm thick diffusional layer exists at the Fe/Al interface. The average peel strength is 12N/mm. Suitable annealing treatment can greatly improve the bonding quality of the interface. The average peel strength increases with increasing annealing temperature, from 12N/mm at 450°C to 21N/mm at 510°C. After annealing at 540°C, the diffusional layer becomes almost three times the original thickness, which results in a sharp drop in the average peel strength to 5N/mm. Cold rolling processing also improves the bonding strength of the clad sheets. The average peel strength of the clad sheet annealed at 510°C increases as the reduction in thickness by cold rolling increases, from 23N/mm for 25% reduction, to 28N/mm for 40% reduction.

Graphical abstract

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