Localization of deformation and formation of residual stresses in metal-matrix composites.

The thermomechanical behavior of a composite material fabricated from high-strength aluminum alloy 6061-T6 reinforced by boron carbide particles is numerically studied. The model microstructure of the composite takes into account the complex shape of particles in an explicit form. Two-dimensional boundary value problems are solved numerically in the plane stress and plane strain formulations using the finite element method. Three types of calculations of the composite deformation are carried out: cooling from the melt to room temperatures, compression from zero initial state and the cooling followed by compression. Sites of the formation of local compressive and tensile stresses in the metal matrix and ceramic particles are found out. Volumetric tensile stresses are detected even under all-round compression realized during cooling. Plastic strain localization and residual stress concentration in the matrix and particle are found to depend on the type of the loading. [ABSTRACT FROM AUTHOR]