Fine structure of interphase boundaries in hard alloys of the chromium carbide–titanium system

Abstract

The structure of interphase boundaries in hard alloys fabricated by the explosive compacting of the powder mixtures of chromium carbide (Cr3C2) and titanium is investigated. It is established by electron microscopy that similar boundaries have thicknesses of about 100 nm, over the extension of which a smooth variation in chromium and titanium contents is observed at the almost identical carbon concentration. The boundary structure is nonuniform over the thickness, notably, a layer with a thickness of 5–7 nm and an amorphous structure is revealed between two crystalline interlayers. It is shown that the revealed layers are the layers of specific “boundary phases” not corresponding to any phase of the equilibrium phase diagram of the Cr–C–Ti system.