Title of Invention	A GRINDING WHEEL AND A METHOD OF MANUFACTURE THEROF
Abstract	A method of manufacture of a grinding wheel comprising the steps of mounting the grinding wheel on a turntable for exposing the working surface of the same to micro wave radiation of frequency .2.5 GHz in amulti-mode cavity heating device over a predeterm ined period oftim e, the portions of the said wheel not intended for receiving radiation being selective.ly masked.

Full Text

This invention relates to a grinding wheel and a method of manufacture thereof. Grinding Is acknowledged as a finishing process for components requiring fine tolerance and finish. However grinding wheels known to the art are usually associated with problems, such as, Inhomogenelty In size of the- abrasive grain, its shape, and distribution making the grinding operation unpredictable and incapable of meeting design requirements. Finish grinding requirements of high strength alloy tool steels necessarily need an economical wheel which will Induce minimum thermal damage to the material being ground. The most preferred alumina wheel which is in practice for finish-grinding of high speed steel tools, has limitations on wheel life due to presence of much harder vanadium carbide particles in the work material, which in turn rub off the wheel material leading to heavy wheel loading and bond failure; also results in faster occurrence of grinding burn - a thermal damage. To overcome these limitations in using alumina wheels, it is imperative to enhance abrasive/grit refinement and bond homogeneity by way of surfaclal treatment of grinding wheels. This invention therefore proposes a grinding wheel which eliminates or at least greatly minimises the foregoing drawbacks associated with the known grinding wheels. The method of manufacture of a grinding wheel, according to this invention, comprises the steps of mounting the grinding wheel on a turn-table for exposing the working surface of the same to microwave radiation of frequency 2.5 GHz in a multi-mode cavity heating device over a predetermined period of time, the portions of the said wheel not intended for receiving radiation being selectively masked. This invention will now be described with reference to the accompanying .drawings the single Figure in which illustrates, by way of exsunple, and not by way of limitation^ one of the possible devices used for carrying out the method proposed herein. In the drawings B is the grinding wheel, C is a rotating table on which the grinding wheel is placed, D is a mask for preventing radiation on specific areas and E are the indicators. The grinding wheel is kept on the rotating table, so that as the table rotates and the radiation is turned on, the working surface of the wheel is uniformly exposed to the radiation. The radiation is of frequency 2.5 GHz in a multi-mode cavity heating device F (of which A is the multi-mode cavity) over a predetermined period of time, say, upto 30 miniutes * The portions of the said wheel not intended for receiving radiation being selectively masked at D. EXAMPLE Post processing of semi-fried vitrified alumina wheel was carried out by exposing the periphery of the wheel (working surface upto 10 mm thickness) to microwave radiation at 2.5 GHz frequency in a multi-mode cavity microwave heating facility for a period of time up to 30 minutes. The inner race as well as the left out portion of the grinding wheel were selectively masked with carbon blocks to protect from microwave irradiation. The treated grinding wheels proposed herein have grain refinement/bond homogeneity and were found to have improved grinding performance, with enhanced wheel life. The terms and expressions herein are of description and not of limitation, and do not exclude any equivalents of the features described and illustrated, but it is understood that various other embodiments of this invention are possible without departing from the scope and ambit of this invention. We Claim: 1. A method of manufacture of a grinding wheel comprising the steps of mounting the grinding wheel on a turn-table for exposing the working surface of the same to microwave radiation of frequency 2.5 GHz in a multi-mode cavity heating device over a predetermined period of time, the portions of the said wheel not intended for receiving radiation being selectively masked. 2. A method as claimed in Claim 1 wherein the period of time of exposure to microwave radiation is up to 30 minutes. 3. A method as claimed in Claim 1 or Claim 2 wherein the working surface of the wheel has a thickness up to 10 mm. 4. A method as claimed in any one of the preceding Claims wherein the selective masking is carried out by carbon blocks placed on the said wheel. 5. A method as claimed in any one of the preceding Claims wherein the grinding wheel is a semi-fried vitrified alumina wheel. 6. A method of manufacture of a grinding wheel substantially as herein described and illustrated with reference to the accompanying drawings. 7. A grinding wheel manufactured by a method as claimed in any one of the preceding Claims• Dated this the 24th March 2003

Documents:

0248-che-2003 abstract-duplicate.pdf

0248-che-2003 claims-duplicate.pdf

0248-che-2003 description (complete)-duplicate.pdf

0248-che-2003 drawings-duplicate.pdf

248-che-2003-abstract.pdf

248-che-2003-claims.pdf

248-che-2003-correspondnece-others.pdf

248-che-2003-correspondnece-po.pdf

248-che-2003-description(complete).pdf

248-che-2003-drawings.pdf

248-che-2003-form 1.pdf

248-che-2003-form 19.pdf

248-che-2003-form 26.pdf