A metallographic study of extruded reinforced composites based on iron and copper

Microprobe analysis has been applied to the boundary layers between fibers and matrix to examine the phase composition in relation to mode of extrusion for composite materials based on iron and copper as reinforced with molybdenum and steel fibers. The width of the interaction zone varies from 2 to 4 µm. The phases correspond to the phase diagrams for these systems. Fractography indicates the failure mechanism for reinforced composites under conditions of stress and strain. At the points of application of shock loads, there is planar transverse fracture in the fibers by the cleavage mechanism. The peripheral layers are subject to viscous failure in the fibers with the formation of necks. Extrusion produces plastic strain uniform throughout the fiber length, and there are no breaks in the fibers, which provides conditions for complete realization of the strength of the reinforcing phase.