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US 5,776,214 AGranted
Method for making abrasive grain and abrasive articles
AssigneeMinnesota Mining and Manufacturing Company
InventorWilliam P. Wood
Life of this patent
Estimating the term…
Abstract
Method for making alpha alumina-based abrasive grain from a dispersion comprising boehmite. The abrasive grain can be incorporated into abrasive products such as coated abrasives, bonded abrasives, and non-woven abrasives.
Claims44
A method for making alpha alumina-based ceramic abrasive grain, said method comprising the steps of:
- (a) preparing a homogeneous dispersion by combining components comprising liquid medium, acid, greater than 60 percent by weight boehmite, based on the total solids content of said dispersion, and, on a metal oxide basis, at least 0.1 percent by weight of at least one of metal oxide or precursor thereof, said dispersion containing less than 0.05 percent by weight alpha alumina seeds, based on the total metal oxide content of said dispersion, and the amount of said boehmite being greater than 60 percent by weight, based on the total weight of said dispersion;
- (b) converting the dispersion to alpha alumina-based ceramic precursor material;
- and
- (c) sintering the precursor material to provide alpha alumina-based ceramic abrasive grain having a density greater than 90 percent of theoretical,
- wherein said converting step includes extruding the dispersion such that said abrasive grain has an essentially uniform composition and hardness, and wherein extruding the dispersion includes compacting the dispersion by applying a pressure of at least 3.5.times.10.sup.4 kg/m.sup.2 to the dispersion.
2 more elements
A method for making alpha alumina-based ceramic abrasive grain, said method comprising the steps of:
- (a) preparing a homogeneous dispersion by combining components comprising aqueous liquid medium, acid, greater than 60 percent by weight boehmite, based on the total solids content of said dispersion, and, on a metal oxide basis, at least 0.1 percent by weight of at least one of metal oxide or precursor thereof, said dispersion containing on a metal oxide basis, less than 0.05 percent by weight nucleating agent, based on the total metal oxide content of said dispersion, and the amount of said boehmite being greater than 60 percent by weight, based on the total weight of said dispersion;
- (b) converting the dispersion to alpha alumina-based ceramic precursor material;
- and
- (c) sintering the precursor material to provide alpha alumina-based ceramic abrasive grain, having a density greater than 90 percent of theoretical,
- wherein said converting step includes extruding the dispersion such that said abrasive grain has an essentially uniform composition and hardness, and wherein extruding the dispersion includes compacting the dispersion by applying a pressure of at least 3.5.times.10.sup.4 kg/m.sup.2 to the dispersion.
2 more elements
A method for making alpha alumina-based ceramic abrasive grain, said method comprising the steps of:
- (a) preparing a homogeneous dispersion by combining components comprising aqueous liquid medium, acid, greater than 60 percent by weight boehmite, based on the total solids content of said dispersion, and, on a metal oxide basis, at least 0.1 percent by weight of at least one of metal oxide or precursor thereof, said dispersion containing, on a metal oxide basis, less than 0.05 percent by weight nucleating material, based on the total metal oxide content of said dispersion, and the amount of said boehmite being greater than 60 percent by weight, based on the total weight of said dispersion;
- (b) converting the dispersion to alpha alumina-based ceramic precursor material;
- and
- (c) sintering the precursor material to provide alpha alumina-based ceramic abrasive grain having a density greater than 90 percent of theoretical,
- wherein said converting step includes extruding the dispersion such that said abrasive gain has an essentially uniform composition and hardness, and wherein extruding the dispersion includes compacting the dispersion by applying a pressure of at least 3.5.times.10.sup.4 kg/m.sup.2 to the dispersion.
2 more elements
A method for making alpha alumina-based ceramic abrasive grain, said method comprising the steps of:
- (a) preparing a first dispersion by combining components comprising liquid medium, acid, boehmite, and at least one of metal oxide or precursor thereof,
- (b) drying said first dispersion to provide first alpha alumina-based precursor material;
- (c) combining components comprising aqueous liquid medium, boehmite, and said first alpha alumina-based precursor material to provide a second, homogeneous dispersion comprising aqueous liquid medium, acid, greater than 60 percent by weight boehmite, based on the total solids content of said second dispersion, and, on a metal oxide basis, at least 0.1 percent by weight of at least one of metal oxide or precursor thereof, said dispersion containing less than 0.05 percent by weight nucleating agent, based on the total metal oxide content of said second dispersion, and the amount of said boehmite being greater than 60 percent by weight, based on the total weight of said dispersion;
- (d) converting said second dispersion to second alpha alumina-based ceramic precursor material;
- and
- (e) sintering the second precursor material to provide alpha alumina-based ceramic abrasive grain having a density greater than 90 percent of theoretical,
- wherein said converting step includes extruding the dispersion such that said abrasive grain has an essentially uniform composition and hardness, and wherein extruding the dispersion includes compacting the dispersion by applying a pressure of at least 3.5.times.10.sup.4 kg/m.sup.2 to the dispersion.
4 more elements
A method for making alpha alumina-based ceramic abrasive grain, said method comprising the steps of:
- (a) preparing a homogeneous dispersion by combining components comprising liquid medium, acid, greater than 60 percent by weight boehmite, based on the total solids content of said dispersion, and, on a metal oxide basis, at least 0.1 percent by weight of at least one of metal oxide or precursor thereof, said dispersion containing, on a metal oxide basis, less than 0.05 percent by weight nucleating agent, based on the total metal oxide content of said dispersion, and the amount of said boehmite being greater than 60 percent by weight, based on the total weight of said dispersion;
- (b) converting the dispersion to alpha alumina-based ceramic precursor material;
- and
- (c) sintering the precursor material to provide alpha alumina-based ceramic abrasive grain, having a density greater than 90 percent of theoretical,
- wherein said converting step includes extruding the dispersion such that said abrasive grain has an essentially uniform composition and hardness, and wherein extruding the dispersion includes compacting the dispersion by applying a pressure of at 3.5.times.10.sup.4 kg/m.sup.2 to the dispersion.
2 more elements
A method for making alpha alumina-based ceramic abrasive grain, said method comprising the steps of:
- (a) preparing a homogeneous dispersion by combining components comprising liquid medium, acid, greater than 60 percent by weight boehmite, based on the total solids content of said dispersion, and, on a metal oxide basis, at least 0.1 percent by weight of at least one of metal oxide or precursor thereof, said dispersion containing, on a metal oxide basis, less than 0.05 percent by weight of nucleating material, based on the total metal oxide content of said dispersion, and the amount of said boehmite being greater than 60 percent by weight, based on the total weight of said dispersion;
- (b) converting the dispersion to alpha alumina-based ceramic precursor material;
- and
- (c) sintering the precursor material to provide alpha alumina-based ceramic abrasive grain having a density greater than 90 percent of theoretical,
- wherein said converting step includes extruding the dispersion such that said abrasive grain has an essentially uniform composition and hardness, and wherein extruding the dispersion includes compacting the dispersion by applying a pressure of at least 3.5.times.10.sup.4 kg/m.sup.2 to the dispersion.
2 more elements
A method for making an abrasive article, said method comprising the steps of:
- (a) preparing a dispersion by combining components comprising liquid medium, acid, greater than 60 percent by weight boehmite, based on the total solids content of said dispersion, and, on a metal oxide basis, at least 0.1 percent by weight of at least one of metal oxide or precursor thereof, said dispersion containing less than 0.05 percent by weight alpha alumina seeds, based on the total metal oxide content of said dispersion, and the amount of said boehmite being greater than 60 percent by weight, based on the total weight of said dispersion;
- (b) converting the dispersion to alpha alumina-based ceramic precursor material;
- (c) sintering the precursor material to provide alpha alumina-based ceramic abrasive grain having a density of greater than 90 percent of theoretical;
- and
- (d) combining at least a plurality of said alpha alumina-based ceramic abrasive grain with binder to provide an abrasive article,
- wherein said converting step includes extruding the dispersion such that said abrasive grain has an essentially uniform composition and hardness, and wherein extruding the dispersion includes compacting the dispersion by applying a pressure of at least 3.5.times.10.sup.4 kg/m.sup.2 to the dispersion.
3 more elements
A method for making alpha alumina-based ceramic abrasive grain, said method comprising the steps of:
- (a) preparing a dispersion by combining components comprising liquid medium, greater than 60 percent by weight boehmite, based on the total solids content of said dispersion, and a colloidal, metal oxide sol, said sol providing said dispersion, on a metal oxide basis, with at least 0.1 percent by weight metal oxide, based on the total metal oxide content of said dispersion, and the amount of said boehmite being greater than 60 percent by weight, based on the total weight of said dispersion;
- (b) converting the dispersion to alpha alumina-based ceramic precursor material;
- and
- (c) sintering the precursor material to provide alpha alumina-based ceramic abrasive grain having a density of greater than 90 percent of theoretical,
- wherein said converting step includes extruding the dispersion such that said abrasive grain has an essentially uniform composition and hardness, and wherein extruding the dispersion includes compacting the dispersion by applying a pressure of at least 3.5.times.10.sup.4 kg/m.sup.2 to the dispersion.
2 more elements
A method for making alpha alumina-based ceramic abrasive grain, said method comprising the steps of:
- (a) preparing a first dispersion by combining components comprising liquid medium, boehmite, and a colloidal, metal oxide sol;
- (b) drying said first dispersion to provide first alpha alumina-based precursor material;
- (c) combining components comprising aqueous liquid medium, boehmite, and said first alpha alumina-based precursor material to provide a second dispersion comprising aqueous liquid medium, greater than 60 percent by weight boehmite, based on the total solids content of said second dispersion, and a colloidal, metal oxide sol, said sol providing said second dispersion, on a metal oxide basis, with at least 0.1 percent by weight metal oxide, based on the total metal oxide content of said second dispersion, and the amount of said boehmite being greater than 60 percent by weight, based on the total weight of said dispersion;
- (d) converting said second dispersion to second alpha alumina-based ceramic precursor material;
- and
- (e) sintering the second precursor material to provide alpha alumina-based ceramic abrasive grain having a density of greater than 90 percent of theoretical,
- wherein said converting step includes extruding the dispersion such that said abrasive grain has an essentially uniform composition and hardness, and wherein extruding the dispersion includes contacting the dispersion by applying of at least 3.5.times.10.sup.4 kg/m.sup.2 to the dispersion.
4 more elements
A method for making an abrasive article, said method comprising the steps of:
- (a) preparing a dispersion by combining components comprising liquid medium, greater than 60 percent by weight boehmite, based on the total solids content of said dispersion, and a colloidal, metal oxide sol, said sol providing said dispersion, on a metal oxide basis, with at least 0.1 percent by weight metal oxide, based on the total metal oxide content of said dispersion, and the amount of said boehmite being greater than 60 percent by weight, based on the total weight of said dispersion;
- (b) converting the dispersion to alpha alumina-based ceramic precursor material;
- (c) sintering the precursor material to provide alpha alumina-based ceramic abrasive grain having a density of greater than 90 percent of theoretical;
- and
- (d) combining at least a plurality of said alpha alumina-based ceramic abrasive grain with binder to provide an abrasive article,
- wherein said converting step includes extruding the dispersion such that said abrasive grain has an essentially uniform composition and hardness, and wherein extruding the dispersion includes compacting the dispersion by applying a pressure of at least 3.5.times.10.sup.4 kg/m.sup.2 to dispersion.
3 more elements
The method according to claime 43 wherein step (e) further includes combining fused alumina abrasive grain with said binder.
Dependencies are inferred from the claim text.