Alumina-zirconia-silicon carbide-magnesia ceramic cutting tools
AssigneeKennametal Inc.
InventorsPankaj K. Mehrotra, Elizabeth R. Billman
Life of this patent
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Abstract
A metalcutting insert is provided with an alumina based ceramic composition composed of (in volume percent, v/o): about 1.5 to 37.5 silicon carbide whiskers; about 5 to 17.5 zirconia; residue of a magnesium oxide addition added in an amount effective to enhance the metalcutting lifetime of the cutting edge of the insert; and an alumina based matrix in which the silicon carbide whiskers, zirconia and residue of magnesium oxide are substantially homogeneously distributed. At least 2 v/o of the alumina based ceramic composition is tetragonal zirconia.
Claims34
A metalcutting insert comprising:
- a rake face;
- a flank face;
- a cutting edge at a juncture of said rake face and said flank face;
- said cutting insert having an alumina based ceramic composition consisting essentially of:
- about 1.5 to 32.5 v/o silicon carbide whiskers;
- about 5 to 17.5 v/o zirconia;
- a residue of a magnesia addition added in the amount of about 0.03 to 3 v/o;
- alumina forming essentially the remainder of said composition;
- wherein said silicon carbide whiskers, said zirconia and said residue of said magnesia addition are substantially homogeneously dispersed in a matrix formed of said alumina;
- and
- wherein at least about 2.0 v/o of said ceramic composition is tetragonal zirconia.
A metalcutting insert comprising:
- a rake face;
- a flank face;
- a cutting edge at a juncture of said rake face and said flank face;
- and said cutting insert having an alumina based ceramic composition consisting of
- about 1.5-32.5 v/o SiC.sub.w,
- about 5 to 17.5 v/o ZrO.sub.2,
- a residue of a magnesia addition added in an amount of about 0.03 to 3 v/o,
- an alumina matrix wherein said silicon carbide whiskers, said zirconia and said residue of said magnesium oxide addition are substantially homogeneously distributed,
- and wherein tetragonal zirconia forms at least 2 v/o of said alumina based ceramic composition.
A metalcutting insert comprising:
- a rake face;
- a flank face;
- a cutting edge at a juncture of said rake face and said flank face;
- said cutting insert having an alumina based ceramic composition consisting essentially of:
- about 1.5 to 32.5 v/o silicon carbide whiskers;
- about 2 to 35 v/o titanium carbide;
- about 5 to 17.5 v/o zirconia;
- a residue of a magnesia addition added in the amount of about 0.03 to 3 v/o;
- alumina forming essentially the remainder of said composition;
- wherein said silicon carbide whiskers, said titanium carbide, said zirconia and said residue of said magnesia addition are substantially homogeneously dispersed in a matrix formed of said alumina;
- and
- wherein at least about 2.0 v/o of said ceramic composition is tetragonal zirconia.
A metalcutting insert comprising:
- a rake face;
- a flank face;
- a cutting edge at a juncture of said rake face and said flank face;
- and said cutting insert having an alumina based ceramic composition consisting of
- about 1.5-32.5 v/o SiC.sub.w,
- about 5 to 17.5 v/o ZrO.sub.2,
- about 2 to 35 v/o titanium carbide,
- a residue of a magnesia addition added in an amount of about 0.03 to 3 v/o,
- an alumina matrix wherein said silicon carbide whiskers, said titanium carbide, said zirconia and said residue of said magnesium oxide addition are substantially homogeneously distributed,
- and wherein tetragonal zirconia forms at least 2 v/o of said alumina based ceramic composition.
Dependencies are inferred from the claim text.