US4007020A
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US
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Refractory abrasive body containing chromium oxide and method of producing it
Assignee: Kaman Sciences Corp
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Filing: 1973-11-19
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Granted: 1977-02-22
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Expires: 1993-11-19
Abstract
Abstract A new ceramic treatment process and product and, more particularly, a process for forming and treating and shaping and treating of porous skeletal bodies to produce hardened dimensionally stable end products at relatively low temperatures and the resulting materials produced thereby which comprises the steps of treating a porous skeletal body by impregnating the interstices of the porous body with a compound of a metal capable of being converted to an oxide in situ at relatively low temperatures, heating the body so impregnated at temperatures well below normal vitrification to a temperature of at least 600° F. and for a period of time sufficient to convert the compound impregnated therein to an oxide and repeating the impregnation and heating steps until the desired degree of hardness is obtained. The invention further contemplates the forming of the porous body from relatively finely divided materials which may be relatively pure powders, mixtures of powders or impure powders, including additives in the form of discrete particles, fibers, fillers and the like, which powders are molded and bound together or bound together and molded with a binder which may comprise the impregnating compound or other suitable binder prior to treatment.
Inventors
- 👤 Peter K. Church
- 👤 Oliver J. Knutson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 11:58
CPC Classifications
B; B24; B24D; B24D3/00; B24D3/02; B24D3/04; B24D3/14; B24D3/18; B24D3/34; B24D3/348
Claims Analysis
Total Claims: 56
Claim 1
Independent Claim
148 words
A method of producing a chemically hardened abrasive body which comprises: closely packing finely divided discrete relatively fine refractory oxide particles, at least the surface of said particles consists of a refractory oxide of at least one metallic element having a vitrification temperature in excess of 600° F., and including a substantial amount of relatively coarse abrasive grain to form a porous structure; impregnating said porous structure with a solution of an inorganic chromium compound capable of being converted to an oxide on being heated to a temperature below the vitrification temperature of said refractory particles and grain; drying and curing said impregnated structure by heating same to a temperature below the vitrification and sinter temperatures of the particles and grain but sufficient to convert the chromium compound to an oxide; and, repeating the impregnation and heat curing steps at least once to harden and densify the structure.
Claim 2
Independent Claim
148 words
A method of producing a chemically hardened abrasive body which comprises: closely packing finely divided discrete relatively fine refractory oxide particles, at least the surface of said particles consists of a refractory oxide of at least one metallic element having a vitrification temperature in excess of 600° F., and including a substantial amount of relatively coarse abrasive grain to form a porous structure; impregnating said porous structure with a solution of an inorganic chromium compound capable of being converted to an oxide on being heated to a temperature below the vitrification temperature of said refractory particles and grain; drying and curing said impregnated structure by heating same to a temperature below the vitrification and sinter temperatures of the particles and grain but sufficient to convert the chromium compound to an oxide; and, repeating the impregnation and heat curing steps at least once to harden and densify the structure.
Claim 3
Dependent Claim
56 words
The method of claim 1 wherein at least the surface of the particles is selected from the group of inorganic refractories consisting of oxides of aluminum, barium, beryllium, calcium, cerium, chromium, cobalt, copper, gallium harnium, iron, lanthanum, magnesium, manganese, molybdenum, nickel, niobium, silicon, tantalum, thorium, tin, titanium, tungsten, uranium, vanadium, yttrium, zinc, zirconium, and mixtures thereof.
Claim 4
Dependent Claim
11 words
The method of claim 1 wherein the solution is chromic acid.
Claim 5
Dependent Claim
66 words
The method of claim 1 which includes as a last step the impregnation of the hardened abrasive structure with phosphoric acid and heating and curing said structure by raising the temperature thereof to at least about 600° F., but below the vitrification and sinter temperature of the refractory particles and grain in increments over a period of time sufficient to completely dry and harden the structure.
Claim 6
Dependent Claim
38 words
The method of claim 1 wherein a clay or inorganic chromium compound binder is mixed with the finely divided particles prior to forming the structure which serves to hold the particles together during the impregnation and cure cycles.
Claim 7
Dependent Claim
40 words
The method of claim 1 wherein the abrasive grain is selected from the group of abrasive grains consisting of chromia, tin oxide, titania, aluminum oxide, black silicon carbide, green silicon carbide, bauxite, silicic acid, iron oxide, diamonds and mixtures thereof.
Claim 8
Independent Claim
128 words
A method of producing a chemically hardened abrasive body which comprises: closely packing finely divided discrete relatively fine refractory particles having a vitrification temperature in excess of 600° F. and including a substantial amount of relatively coarse abrasive grain to form a porous structure; impregnating said porous structure with a solution of an inorganic chromium compound capable of being converted to an oxide on being heated to a temperature below the vitrification temperature of refractory particles and grain; drying and curing said impregnated structure by heating same to a temperature below the vitrification and sinter temperature of the particles and grain but sufficient to convert the chromium compound to an oxide; and, repeating the impregnation and heat curing steps at least once to harden and densify the structure.
Claim 9
Independent Claim
128 words
A method of producing a chemically hardened abrasive body which comprises: closely packing finely divided discrete relatively fine refractory particles having a vitrification temperature in excess of 600° F. and including a substantial amount of relatively coarse abrasive grain to form a porous structure; impregnating said porous structure with a solution of an inorganic chromium compound capable of being converted to an oxide on being heated to a temperature below the vitrification temperature of refractory particles and grain; drying and curing said impregnated structure by heating same to a temperature below the vitrification and sinter temperature of the particles and grain but sufficient to convert the chromium compound to an oxide; and, repeating the impregnation and heat curing steps at least once to harden and densify the structure.
Claim 10
Dependent Claim
28 words
The method of claim 7 wherein the refractory particles and grain are packed into a mold of predetermined shape at least during the initial impregnation and cure steps.
Claim 11
Dependent Claim
38 words
The method of claim 7 wherein a clay or inorganic chromium compound binder is mixed with the finely divided particles prior to forming the structure which serves to hold the particles together during the impregnation and cure cycles.
Claim 12
Dependent Claim
40 words
The method of claim 7 wherein the abrasive grain is selected from the group of abrasive grains consisting of chromia, tin oxide, titania, aluminum oxide, black silicon carbide, green silicon carbide, bauxite, silicic acid, iron oxide, diamonds and mixtures thereof.
Claim 13
Dependent Claim
51 words
The method of claim 7 wherein the particles are selected from the group of inorganic refractories consisting of oxides of aluminum, barium, beryllium, calcium, cerium, chromium, cobalt, copper, gallium, hafnium, iron, lanthanum, magnesium, manganese, molybdenum, nickel, niobium, silicon, tantalum, thorium, tin, titanium, tungsten, uranium, vanadium, yttrium, zinc, zirconium, and mixtures thereof.
Claim 14
Dependent Claim
11 words
The method of claim 7 wherein the solution is chromic acid.
Claim 15
Dependent Claim
66 words
The method of claim 7 which includes as a last step the impregnation of the hardened abrasive structure with phosphoric acid and heating and curing said structure by raising the temperature thereof to at least about 600° F., but below the vitrification and sinter temperature of the refractory particles and grain in increments over a period of time sufficient to completely dry and harden the structure.
Claim 16
Independent Claim
129 words
A method of producing a chemically hardened abrasive body which comprises: providing a non-vitrified skeletal core of relatively fine inorganic refractory material having a vitrification temperature in excess of 600° F. and including a substantial amount of relatively coarse abrasive grain; impregnating said core with a solution of an inorganic chromium compound capable of being converted to an oxide on being heated to a temperature below the vitrification temperature of said refractory material and abrasive grain; drying and curing said impregnated core by heating the core to a temperature below the vitrification and sinter temperature of said refractory material and abrasive grain but sufficient to convert the chromium compound to an oxide; and repeating the impregnation and heat curing steps at least once to harden and densify the core.
Claim 17
Independent Claim
129 words
A method of producing a chemically hardened abrasive body which comprises: providing a non-vitrified skeletal core of relatively fine inorganic refractory material having a vitrification temperature in excess of 600° F. and including a substantial amount of relatively coarse abrasive grain; impregnating said core with a solution of an inorganic chromium compound capable of being converted to an oxide on being heated to a temperature below the vitrification temperature of said refractory material and abrasive grain; drying and curing said impregnated core by heating the core to a temperature below the vitrification and sinter temperature of said refractory material and abrasive grain but sufficient to convert the chromium compound to an oxide; and repeating the impregnation and heat curing steps at least once to harden and densify the core.
Claim 18
Dependent Claim
55 words
The method of claim 14 wherein the skeletal core is of a material selected from the group of inorganic refractories consisting of oxides of aluminum, barium, beryllium, calcium, cerium, chromium, cobalt, copper, gallium, hafnium, iron, lanthanum, magnesium, manganese, molybdenum, nickel, niobium, silicon, tantalum, thorium, tin, titanium, tungsten, uranium, vanadium, yttrium, zinc, zirconium, and mixtures thereof.
Claim 19
Dependent Claim
40 words
The method of claim 14 wherein the abrasive grain is selected from the group of abrasive grains consisting of chromia, tin oxide, titania, aluminum oxide, black silicon carbide, green silicon carbide, bauxite, silicic acid, ferric oxide, diamonds and mixtures thereof.
Claim 20
Dependent Claim
11 words
The method of claim 14 wherein the solution is chromic acid.
Claim 21
Dependent Claim
66 words
The method of claim 14 which includes as a last step the impregnation of the hardened abrasive structure with phosphoric acid and heating and curing said structure by raising the temperature thereof to at least about 600° F., but below the vitrification and sinter temperature of the refractory particles and grain in increments over a period of time sufficient to completely dry and harden the structure.
Claim 22
Dependent Claim
12 words
The method of claim 1 wherein the abrasive grain is silicon carbide.
Claim 23
Dependent Claim
12 words
The method of claim 7 wherein the abrasive grain is silicon carbide.
Claim 24
Dependent Claim
12 words
The method of claim 14 wherein the abrasive grain is silicon carbide.
Claim 25
Dependent Claim
11 words
The method of claim 1 wherein the abrasive grain is diamond.
Claim 26
Dependent Claim
11 words
The method of claim 7 wherein the abrasive grain is diamond.
Claim 27
Dependent Claim
11 words
The method of claim 14 wherein the abrasive grain is diamond.
Claim 28
Dependent Claim
12 words
The method of claim 1 wherein the abrasive grain is aluminum oxide.
Claim 29
Dependent Claim
12 words
The method of claim 7 wherein the abrasive grain is aluminum oxide.
Claim 30
Dependent Claim
12 words
The method of claim 14 wherein the abrasive grain is aluminum oxide.
Claim 31
Independent Claim
141 words
A method of producing a grinding structure which comprises: wetting abrasive grains selected from the group consisting of chromia; tin oxide; titania; aluminum oxide; black silicon carbide; green silicon carbide; bauxite; silicic acid; ferric oxide; diamonds; and, mixtures thereof with a solution of a chromium compound capable of being converted to an oxide on being heated to a temperature below the vitrification temperature of said abrasive grains; heating said wetted grains to a temperature below the vitrification and sinter temperature of the grains but sufficient to convert the chromium compound to an oxide; repeating the wetting and heat curing steps at least once to increase the hardness of the oxide; and, bonding the abrasive grains into a grinding structure with a bonding material selected from the group of bonding materials consisting of resin, clay, alumina and soluble inorganic chromium compound binders.
Claim 32
Independent Claim
141 words
A method of producing a grinding structure which comprises: wetting abrasive grains selected from the group consisting of chromia; tin oxide; titania; aluminum oxide; black silicon carbide; green silicon carbide; bauxite; silicic acid; ferric oxide; diamonds; and, mixtures thereof with a solution of a chromium compound capable of being converted to an oxide on being heated to a temperature below the vitrification temperature of said abrasive grains; heating said wetted grains to a temperature below the vitrification and sinter temperature of the grains but sufficient to convert the chromium compound to an oxide; repeating the wetting and heat curing steps at least once to increase the hardness of the oxide; and, bonding the abrasive grains into a grinding structure with a bonding material selected from the group of bonding materials consisting of resin, clay, alumina and soluble inorganic chromium compound binders.
Claim 33
Dependent Claim
18 words
The method of claim 28 wherein the bonding of the abrasive grains is with a resin bonding material.
Claim 34
Dependent Claim
101 words
The method of claim 28 wherein the bonding of the abrasive grains is by: closely packing the abrasive grains to form a porous structure; impregnating the porous structure with a solution of an inorganic chromium compound capable of being converted to an oxide on being heated to a temperature below the vitrification temperature of the abrasive grains; heat curing the impregnated structure to a temperature below the vitrification and sinter temperature of the grains but sufficient to convert the chromium compound to the oxide; and, repeating the impregnation and heat curing steps at least once to harden and densify the structure.
Claim 35
Independent Claim
232 words
A method of producing a chemically hardened refractory abrasive body having a cutting surface which comprises: wetting finely divided relatively fine refractory oxide particles having a vitrification temperature in excess of 600° F. selected from the group consisting of the oxides of aluminum, barium, beryllium, calcium, cerium, chromium, cobalt, copper, gallium, hafnium, iron, lanthanum, magnesium, manganese, molybdenum, nickel, niobium, silicon, tantalum, thorium, tin, titanium, tungsten, uranium, vanadium, yttrium, zinc, zirconium, and mixtures thereof with a solution of an inorganic chromium compound capable of being converted to an oxide on being heated to a temperature below the vitrification temperature of the refractory particles and relatively coarse abrasive grain; heating said wetted fine particles and coarse grain to a temperature sufficient to convert said chromium compound to the oxide but below the vitrification and sinter temperature of said particles and grain; closely packing the treated particles and grain to form a porous body; impregnating said porous body with a solution of an inorganic chromium compound capable of being converted to an oxide on being heated to a temperature below the vitrification temperature of the particles and grain; curing said impregnated body by heating same to a temperature sufficient to convert said chromium compound to the oxide, but below the vitrification and sinter temperature of the particles and grain; amd, repeating the impregnation and heating steps at least once to harden and densify the body.
Claim 36
Independent Claim
232 words
A method of producing a chemically hardened refractory abrasive body having a cutting surface which comprises: wetting finely divided relatively fine refractory oxide particles having a vitrification temperature in excess of 600° F. selected from the group consisting of the oxides of aluminum, barium, beryllium, calcium, cerium, chromium, cobalt, copper, gallium, hafnium, iron, lanthanum, magnesium, manganese, molybdenum, nickel, niobium, silicon, tantalum, thorium, tin, titanium, tungsten, uranium, vanadium, yttrium, zinc, zirconium, and mixtures thereof with a solution of an inorganic chromium compound capable of being converted to an oxide on being heated to a temperature below the vitrification temperature of the refractory particles and relatively coarse abrasive grain; heating said wetted fine particles and coarse grain to a temperature sufficient to convert said chromium compound to the oxide but below the vitrification and sinter temperature of said particles and grain; closely packing the treated particles and grain to form a porous body; impregnating said porous body with a solution of an inorganic chromium compound capable of being converted to an oxide on being heated to a temperature below the vitrification temperature of the particles and grain; curing said impregnated body by heating same to a temperature sufficient to convert said chromium compound to the oxide, but below the vitrification and sinter temperature of the particles and grain; amd, repeating the impregnation and heating steps at least once to harden and densify the body.
Claim 37
Independent Claim
232 words
A method of producing an abrasive structure which comprises: wetting abrasive grains selected from the group consisting of chromia, tin oxide, titania, aluminum oxide, black silicon carbide, green silicon carbide, bauxite, silicic acid, ferric oxide, diamonds and mixtures thereof with a wetting reagent selected from the group consisting of a solution of an inorganic chromium compound capable of being converted to an oxide on being heated; a solution of an inorganic chromium compound capable of being converted to an oxide on being heated plus kaolin; a solution of an inorganic chromium compound capable of being converted to an oxide on being heated plus aluminum oxide; a solution of an inorganic chromium compound capable of being converted to an oxide on being heated plus Kentucky ball clay; and, a solution of an inorganic chromium compound capable of being converted to an oxide on being heated plus bentonite; heating said wetting grains to a temperature sufficient to convert the chromium compound on the surface thereof to an oxide but below the vitrification and sinter temperature of the grains to cure said chromium compound to an oxide; subjecting the grains to repeated wetting and curing steps until the desired hardness of the oxide is achieved; and, bonding the abrasive grains into a grinding structure with a binder selected from the group of binder materials consisting of resin, clay, alumina and soluble inorganic chromium compound binders.
Claim 38
Independent Claim
232 words
A method of producing an abrasive structure which comprises: wetting abrasive grains selected from the group consisting of chromia, tin oxide, titania, aluminum oxide, black silicon carbide, green silicon carbide, bauxite, silicic acid, ferric oxide, diamonds and mixtures thereof with a wetting reagent selected from the group consisting of a solution of an inorganic chromium compound capable of being converted to an oxide on being heated; a solution of an inorganic chromium compound capable of being converted to an oxide on being heated plus kaolin; a solution of an inorganic chromium compound capable of being converted to an oxide on being heated plus aluminum oxide; a solution of an inorganic chromium compound capable of being converted to an oxide on being heated plus Kentucky ball clay; and, a solution of an inorganic chromium compound capable of being converted to an oxide on being heated plus bentonite; heating said wetting grains to a temperature sufficient to convert the chromium compound on the surface thereof to an oxide but below the vitrification and sinter temperature of the grains to cure said chromium compound to an oxide; subjecting the grains to repeated wetting and curing steps until the desired hardness of the oxide is achieved; and, bonding the abrasive grains into a grinding structure with a binder selected from the group of binder materials consisting of resin, clay, alumina and soluble inorganic chromium compound binders.
Claim 39
Dependent Claim
22 words
The method of claim 32 wherein the wetting agent is a solution of a chromium compound and the oxide is chromium oxide.
Claim 40
Dependent Claim
92 words
The method of claim 32 wherein the bonding of the abrasive grains is by: closely packing the abrasive grains to form a porous structure; impregnating the porous structure with a solution of an inorganic chromium compound capable of being converted to an oxide on being heated; curing said impregnated structure by heating same to a temperature sufficient to convert the chromium compound to the oxide but below the vitrification and sinter temperature of the grains; and, repeating the impregnation and curing steps at least once to harden and densify the grinding structure.
Claim 41
Dependent Claim
18 words
The method of claim 33 wherein the bonding of the abrasive grains is with a resin bonding material.
Claim 42
Independent Claim
82 words
The method of hardening and strengthening of a fully sintered porous grinding structure which comprises: impregnating the structure with a solution of an inorganic chromium compound capable of being converted to an oxide on being heated; curing said impregnated structure by heating same to a temperature sufficient to convert the chromium compound to the oxide but below the vitrification and sinter temperature of the structure; and, repeating the impregnation and curing steps at least once to harden and densify the grinding structure.
Claim 43
Independent Claim
82 words
The method of hardening and strengthening of a fully sintered porous grinding structure which comprises: impregnating the structure with a solution of an inorganic chromium compound capable of being converted to an oxide on being heated; curing said impregnated structure by heating same to a temperature sufficient to convert the chromium compound to the oxide but below the vitrification and sinter temperature of the structure; and, repeating the impregnation and curing steps at least once to harden and densify the grinding structure.
Claim 44
Independent Claim
227 words
A method of making crushed abrasive grain which comprises the steps of: closely packing finely divided relatively fine abrasive particles selected from the group consisting of chromia; tin oxide; titania; aluminum oxide; black silicon carbide; green silicon carbide; bauxite; silicic acid; ferric oxide; diamonds; and, mixtures thereof having a vitrification in excess of 600° F. to form a porous structure; impregnating said porous structure with a solution of an impregnant selected from the group consisting of a solution of an inorganic chromium compound capable of being converted to an oxide on being heated; a solution of an inorganic chromium compound capable of being converted to an oxide on being heated plus kaolin; a solution of an inorganic chromium compound capable of being converted to an oxide on being heated plus bentonite; a solution of an inorganic chromium compound capable of being converted to an oxide on being heated plus aluminum oxide; and a solution of an inorganic chromium compound capable of being converted to an oxide on being heated plus Kentucky ball clay; drying and curing said impregnated structure by heating same to a temperature below the vitrification and sinter temperature thereof but sufficient to convert the chromium compound to the oxide; repeating the impregnation and heat curing steps at least once to harden and densify the structure; and, crushing the structure to form coarse abrasive grains.
Claim 45
Independent Claim
227 words
A method of making crushed abrasive grain which comprises the steps of: closely packing finely divided relatively fine abrasive particles selected from the group consisting of chromia; tin oxide; titania; aluminum oxide; black silicon carbide; green silicon carbide; bauxite; silicic acid; ferric oxide; diamonds; and, mixtures thereof having a vitrification in excess of 600° F. to form a porous structure; impregnating said porous structure with a solution of an impregnant selected from the group consisting of a solution of an inorganic chromium compound capable of being converted to an oxide on being heated; a solution of an inorganic chromium compound capable of being converted to an oxide on being heated plus kaolin; a solution of an inorganic chromium compound capable of being converted to an oxide on being heated plus bentonite; a solution of an inorganic chromium compound capable of being converted to an oxide on being heated plus aluminum oxide; and a solution of an inorganic chromium compound capable of being converted to an oxide on being heated plus Kentucky ball clay; drying and curing said impregnated structure by heating same to a temperature below the vitrification and sinter temperature thereof but sufficient to convert the chromium compound to the oxide; repeating the impregnation and heat curing steps at least once to harden and densify the structure; and, crushing the structure to form coarse abrasive grains.
Claim 46
Independent Claim
123 words
The method of making a diamond grinding wheel which comprises the steps of: forming a slurry of diamond abrasive grains in a solution of an inorganic chromium compound capable of being converted to an oxide at a temperature of at least 600° F., but below that at which the diamond grains will be oxidized; applying a coating of diamond and chromium compound slurry to the grinding surface of a porous abrasive grinding wheel made from an abrasive material selected from the group consisting of silicon carbide, aluminum oxide and mixtures thereof; and, drying and curing the grinding wheel by hearting same to a temperature of at least 600° F., but below vitrification and/or sinter temperatures at which the diamond grains will be oxidized.
Claim 47
Independent Claim
123 words
The method of making a diamond grinding wheel which comprises the steps of: forming a slurry of diamond abrasive grains in a solution of an inorganic chromium compound capable of being converted to an oxide at a temperature of at least 600° F., but below that at which the diamond grains will be oxidized; applying a coating of diamond and chromium compound slurry to the grinding surface of a porous abrasive grinding wheel made from an abrasive material selected from the group consisting of silicon carbide, aluminum oxide and mixtures thereof; and, drying and curing the grinding wheel by hearting same to a temperature of at least 600° F., but below vitrification and/or sinter temperatures at which the diamond grains will be oxidized.
Claim 48
Dependent Claim
18 words
The method of claim 38 in which the slurry includes a substantial amount of silicon carbide grinding grains.
Claim 49
Dependent Claim
90 words
A chemically hardened abrasive body comprising: a closely packed porous mass of a substantial amount of abrasive grain and finely divided discrete particles at least the surface of which consists of a refractory oxide of at least one metallic element having a vitrification temperature in excess of 600° F. essentially devoid of vitreous and/or sinter bonding between the particles with said particles being bonded together by chromic oxide at temperatures below vitrification temperature of the refractory oxide and grain and having substantial deposits of chromic oxide within the pores thereof.
Claim 50
Dependent Claim
90 words
A chemically hardened abrasive body comprising: a closely packed porous mass of a substantial amount of abrasive grain and finely divided discrete particles at least the surface of which consists of a refractory oxide of at least one metallic element having a vitrification temperature in excess of 600° F. essentially devoid of vitreous and/or sinter bonding between the particles with said particles being bonded together by chromic oxide at temperatures below vitrification temperature of the refractory oxide and grain and having substantial deposits of chromic oxide within the pores thereof.
Claim 51
Dependent Claim
72 words
A chemically hardened abrasive oxide body comprising: a closely packed porous mass of a substantial amount of abrasive grain and finely divided discrete particles of a refractory oxide having a vitrification temperature in excess of 600° F. essentially devoid of vitreous and/or sinter bonding between the particles with said particles being bonded together by chromic oxide at temperatures below vitrification temperature of the refractory oxide and grain oxide within the pores thereof.
Claim 52
Dependent Claim
72 words
A chemically hardened abrasive oxide body comprising: a closely packed porous mass of a substantial amount of abrasive grain and finely divided discrete particles of a refractory oxide having a vitrification temperature in excess of 600° F. essentially devoid of vitreous and/or sinter bonding between the particles with said particles being bonded together by chromic oxide at temperatures below vitrification temperature of the refractory oxide and grain oxide within the pores thereof.
Claim 53
Dependent Claim
82 words
A body according to claim 40 wherein the abrasive grain is selected from the group consisting of chromia; tin oxide; titania; aluminum oxide; black silicon carbide; green silicon carbide; bauxite; silicic acid; ferric oxide; diamonds; and, mixtures thereof and the refractory oxide is selected from the group consisting of oxides of aluminum, barium, beryllium, calcium, cerium, chromium, cobalt, copper, gallium, hafnium, iron, lanthanum, magnesium, manganese, molybdenum, nickel, niobium, silicon, tantalum, thorium, tin, titanium, tungsten, uranium, vanadium, yttrium, zinc, zirconium, and mixtures thereof.
Claim 54
Dependent Claim
82 words
A body according to claim 41 wherein the abrasive grain is selected from the group consisting of chromia, tin oxide; titania; aluminum oxide; black silicon carbide; green silicon carbide; bauxite; silicic acid; ferric oxide; diamonds; and, mixture thereof and the refractory oxide is selected from the group consisting of oxides of aluminum, barium, beryllium, calcium, cerium, chromium, cobalt, copper, gallium, hafnium, iron, lanthanum, magnesium, manganese, molybdenum, nickel, niobium, silicon, tantalum, thorium, tin, titanium, tungsten, uranium, vanadium, yttrium, zinc, zirconium, and mixtures thereof.
Claim 55
Dependent Claim
22 words
A body according to claim 43 wherein the refractory oxide is selected from the group consisting of aluminum oxide and silicon carbide.
Claim 56
Dependent Claim
13 words
A body according to claim 44 where the refractory oxide is aluminum oxide.
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USPTO Annuity & Maintenance Windows
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|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-02-22 | 1980-08-23 | 1981-02-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-02-22 | 1984-08-23 | 1985-02-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-02-22 | 1988-08-23 | 1989-02-22 | $7700.00 | Window Closed / Lapsed |