Abstract: Iron or other magnetic metal powder is incorporated with aluminum in the core of a diamond or boron nitride grinding wheel. In addition to providing such characteristics as satisfactory bonding ability, strength, thermal expansion, thermal conductivity and turning characteristics, such cores are better held on a magnetic chuck for the performance of finishing operations.

Abstract: A diamond or cubic boron nitride grinding wheel in which an abrasive section comprising abrasive grits distributed through and held by a phenolic resin matrix is bonded to a non-abrasive core, is improved, in terms of ease of manufacture and elimination of cracking or poor adhesion, by means of a core composition which includes between 5 and 20% by volume of a thermoset resin selected from the group consisting of phenol aldehyde, urea formaldehyde, and melamine formaldehyde resins, particulate metal and graphite, and the remainder being a resin selected from the group consisting of epoxy resins, addition polymers of unsaturated polyesters, and thermosetting polyimide resins, in the range of from 5 to 80% by volume of the core.

Abstract: A metal-resin composite material consisting of a continuous metal matrix and a continuous resin matrix fabricated by hot-pressing a mixture of precursors, the precursors for the metal matrix including an elemental metal having a melting point below 450.degree. C, the metal matrix including an intermetallic compound or alloy having a melting point above 500.degree. C, and the continuous resin matrix being fabricable at a temperature above 250.degree. C. Such composite materials have particular utility as a bonding matrix for premium abrasives such as diamond and boron nitride, to form grinding tools.