Abrasive grits formed of ceramic containing oxides of aluminum and yttrium, method of making and using the same and products made therewith
AssigneeMinnesota Mining and Manufacturing Company
InventorsLarry D. Monroe, William P. Wood
Life of this patent
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Abstract
Ceramic abrasive grits comprising alpha alumina and at least about 0.5 percent by weight yttria are prepared by mixing an aqueous dispersion of alpha alumina monohydrate and yttrium compound, gelling the resultant mixture, drying the gel to produce a dried solid, crushing the dried material to produce grits, calcining the dried grits to substantially remove bound volatile materials, and firing the grits to produce a ceramic material. The yttrium for the most part is in the form of a yttrium aluminum garnet. Abrasive products comprising the abrasive grits are also claimed as is a method of grinding a workpiece with such abrasive products.
Claims40
Ceramic abrasive grits comprising alpha alumina and at least about 0.5% by weight yttria.
A coated abrasive sheet material comprising a backing having bonded to at least one side thereof abrasive grits in coarse and fine size grades with at least a portion of the coarse grits being ceramic abrasive grits comprising alpha alumina and at least about 0.5% by weight yttria.
A method of making ceramic abrasive grits, said method comprising the steps of:
- a. mixing an aqueous dispersion of alpha alumina monohydrate and yttrium compound in an amount to provide at least about 0.5% by weight yttria after firing;
- b. gelling the resultant mixture;
- c. drying the gel to produce a dried solid;
- d. crushing the dried material to produce grits;
- e. calcining the dried grits to substantially remove bound volatile materials;
- and
- f. firing the grits to produce a ceramic material.
A method of grinding a workpiece surface comprising:
- a. causing rapid surface movement of an abrasive article comprised of ceramic abrasive grits comprising alpha alumina and at least about 0.5% by weight yttria;
- and
- b. moving the surface of said abrasive article into surface grinding contact with said workpiece surface.
Abrasive grits comprising ceramic produced by a sol-gel process, said ceramic comprising alpha alumina and at least about 0.5 percent by weight yttria.
Abrasive grits comprising ceramic material having a crystalline structure comprising inclusions which have a high alpha alumina content and a low yttrium-aluminum-garnet content surrounded by a zone having a higher yttrium-aluminum garnet content and a lower alpha alumina content.
Dependencies are inferred from the claim text.