Abstract: To form a high density composite structure a mold is filled with relatively large particles of a hard metallic material, such as tungsten carbide; the voids between the particles are filled with substantially smaller particles of the same material and a liquid air-drying, volatile cement is poured over the particles. The filled mold is then covered with a metal brazing powder which is carried through the particle mass by the still-liquid cement. After the cement dries the part is heated in a controlled atmosphere furnace to a temperature above the melting point of the metal powder, and below the melting point of the particle material driving off the cement and causing the balance of the brazing powder to melt and infiltrate the particles to form a composite with a high density of the hard particles embedded in a matrix of the brazing metal. The mold may become brazed to the matrix to form a permanent part of the final structure or may be separable from the matrix after brazing.

Abstract: Metallic parts having a hard wear-resistant surface and the high impact resistance associated with softer materials are formed by coating a plurality of ductile, relatively soft metallic segments with a relatively hard wear-resistant material, stacking the segments so that portions of each of their coated surfaces are exposed to form a composite coated surface, and mechanically locking the segments together to form a unitary member. The members formed by this technique exhibit the surface characteristics associated with the hardened coating such as improved wear, impact and abrasion resistance, and exhibit the bulk physical properties of the base material such as strength and ductility. Moreover, the surface treatment has a depth which would be unobtainable if the part were formed of a single section treated with the surface coating; the coating is not only formed on the exterior surface of the composite part, but extends toward the interior of the part for substantial depths.