The use of PAP-2 aluminum dust to fabricate powder composite materials: the features of technology, structure and physicomechanical composites. Part 1. Manufacturing approaches that provide the creation of composite materials and applied procedures for de

Abstract

Composites Al/Al2O3 (lamellar cermet matrix)–filling agent (discrete metallic filaments, duralumin chips, graphite particles, fused corundum grains, kaolin filaments, and technical alumina spherolites) are fabricated. Industrially produced PAP-2 aluminum powder, which consists of scaled particles with stearin coating (specific surface of the powder is 4,1322 m2/g, its particle sizes vary from 0,03 to 10 μm), was used to form the lamellar cermet matrix. In order to form the composites, the following production operations were used: heat treatment of PAP-2 powder in air to burn-out stearin from the particle surface and substitute it by alumina film, mixing the formed powder product with the filling agent, pressing, and reaction sintering the powder billets in a filtration burning mode in air. A new approach based on the chemical reaction of stearin saponification is proposed to fabricate the Al/Al2O3 composite. In this reaction, stearin on the surface of aluminum particles reacts with caustic soda resulted from the hydrolysis of diluted liquid glass introduced into initial powder. The reaction products (sodium stearate and glycerin) decompose during subsequent heat treatment in air with the formation of coke residue on the particle surface. Physicochemical properties of composites were determined using standard and generally accepted procedures.