GB1348619A - Grinding wheels - Google Patents

Abstract

1348619 Abrasive wheels ERNST WINTER & SOHN 3 Aug 1972 [3 Aug 1971 (2)] 36332/72 Heading C4V A grinding wheel comprising diamond granules and/or boron nitride granules and containing metallic or non-metallic binding agents and one or more fillers, one of which fillers at least consists of granules of graphite or mainly graphite-containing material provided with a metal coating. The proportion of the graphite filler or fillers in the mixture of bond and abrasive granules may be between 1% where a non- metallic binding agent is used or 5% where a metallic binding agent is used and 60% by volume, disregarding the metal coating on the graphite granules. The metal coating may amount to 0À5 to 80% by volume of the metalcoated graphite particles. The grain size of the graphite filler or fillers may be between 2 mm. and 0À01 mm. The metal coating on the graphite granules may consist of one or more of the metals silver, copper, gold, aluminium, beryllium, tungsten, molybdenum, nickel, cobalt, iron, chromium, tin, zinc or cadmium. The different metals may be superposed or alloyed with one another in the coating on the graphite granules. The materials alloyed with the metals of the coatings may be alloyed with non-metals such as carbon, phosphorus, sulphur, boron or silicon. Non-metallic fillers other than the metalcoated graphite granules may be present. The abrasive granules employed may also have metal or non-metallic coatings. Suitable organic binding agents are phenolic or epoxide resins, thermoplasts such as polyamides, elastomers such as Buna or rubber, or polyimides. Other fillers such as silicon carbide or aluminium oxide may be present.