A numerical analysis program, based on slab analysis, was developed to calculate the stresses and strains that occur in the component layers of a composite sheet in the roll bite during the fabrication of clad metal (e.g. silver clad phosphor bronze) by roll bonding. Results calculated using the perfect plastic and strain hardening models were compared with experimental results: the results obtained using the strain hardening model were found to be in better agreement with values of rolling force and thickness of component layers measured after roll bonding. The program requires input data such as roll radius, initial thickness of the specimen, initial cladding thickness fraction, reduction ratio, coefficients offriction between rolls and material and between component layers, and front and back tensions. The coefficients offriction were evaluated indirectly by comparison of the measured rolling force with that calculated using slab analysis. Measured coefficients of friction varied with reduction ratio and initial thickness, but were independent of rolling speed.MST/1334
List of symbolsh thickness of monolithic or composite sheet after rolling, mm hA, hB thickness of soft and hard layers, respectively, mm H initial thickness of monolithic or composite sheet, mm HA, HB initial thickness of soft and hard layers, respectively, mm k A , k B shear yield stress of soft and hard layers, respectively, MN m-2 k A mean shear yield stress of Ag, MN m -2 P vertical pressure, MN m -2 PA, PB rolling pressure on soft and hard layers, respectively, MN m-2 PAB pressure on soft/hard layer interface, MN m-2Pc, Pe calculated and experimental rolling force, respectively q soft/hard layer thickness ratio r reduction ratio RA, RB radius of roll in contact with soft and hard layers, respectively, mm v rolling speed, m s -1
