Analysis of clad sheet bonding by cold rolling

In this paper, clad sheet bonding by cold rolling has been analyzed in dept h using the stream function method and the upper bound theorem. Not only ha ve the curvature, the thickness ratio of the rolled product and rolling for ce, but also the locations of the neutral points and the bond point have be en obtained. It is found that at low total thickness reduction, the neutral point on the upper roll contacting the harder sheet usually more closely a pproaches the entrance of the roll-gap than does neutral point on the lower roll. As the thickness reduction increases, the difference gradually dimin ishes and even reverses. IT is also found that the location of the bond poi nt at the interface is to some extent related to the initial clad ratio. A smaller the clad ratio before rolling may bring the bond point closer to th e entrance of the roll-gap, which means a longer bonded length at the inter face. Based on this analysis, some means of contributing to the promotion o f bond strength are proposed. (C) 2000 Elsevier Science S.A. All rights res erved.