Al–Cu–B4C Composite Materials for the Production of High-Strength Billets

Composite materials based on aluminum are used in various fields of metallurgy and, in particular, for the production of high-strength products whose properties, such as low density, low coefficient of thermal expansion, and thermal stability, satisfy basic requirements imposed in the course of their operation. At present, we observe rapid development of the technologies of production of high-strength aluminum alloys with composite compounds characterized by the improved mechanical characteristics for a given level of plasticity. The existing technologies of modification of the alloys with ceramic materials, such as B 4 C, guarantee the required operating characteristics for cast and, especially, rolled billets. However, high levels of segregation of particles in the aluminum matrix, the heterogeneity of the surface of composite particles in the course of the rolling, and low wettability sharply worsen the quality of billets and, hence, lead to a decrease in the yield of useful products. Solid B 4 C particles form a rigid reinforcing frame in the aluminum matrix of the composite responsible for the unique properties of the aluminum alloy (such as stiffness, strength, thermal, and electric properties). On the basis of the aluminum matrix, we have produced a multicomponent Al–Cu–B 4 C composite material. The matrix material with a copper content of 5% was produced by introducing boron carbide particles (2.0–7.0%) in the stage of melting. It is shown that the technology of injection casting into a given mold decreases the level of porosity, which creates conditions for the production of high-quality composites of the Al– Cu–B 4 C system with high level of the mechanical properties.