Abstract:Finite element (FEM) analysis was used to systematically evaluate the inhomogeneity of deformation in cylindrical samples with various sample-anvil friction coefficients, m. It was found that the level of friction strongly influences the deformation homogeneity, which increases significantly with the friction coefficient although the overall geometry of the samples almost remains the same when m>0.4. The position, at which the effective strain along the maximum radial direction in a compressed sample is equal to the equivalent strain of the sample, does not vary greatly with respect to both equivalent strain of the sample and m. Hardness measurements of compressed cylindrical 5056B Al alloy samples revealed a change of effective strain distribution similar to that revealed by FEM analysis. There exists a quantitative relationship between the hardness and the effective strain if no recrystallization or recovery occurs during the compression process.

Key words: compression; friction coefficient; barreling, cylinder; deformation inhomogeneity