Coated cutting insert
AssigneeSandvik AB
InventorsBjörn Olsson, Björn Ljungberg
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Abstract
The present invention discloses a coated cutting insert particularly useful for dry milling of grey cast iron. The insert is characterized by a WC—Co cemented carbide substrate and a coating including an innermost layer of TiCxNyOz with columnar grains and a top coating of a fine grained α-Al2O3 layer.
Claims7
A cutting insert for milling of grey cast iron comprising a substrate and a coating, said substrate comprising WC, 3-15 weight-% Co and ≦2 weight-% carbides of metals from groups IVb, Vb or VIb of the periodic table and said coating comprising:
- a first (innermost) layer of TiCxNyOz with x+y+z=1 and a thickness of 0.1-2 μm, and with equiaxed grains with size <0.5 μm;
- a layer of TiCxNyOz with x+y+z=1 and a thickness of 2-10 μm with columnar grains with a diameter of about <5 μm;
- a layer of TiCxNyOz with x+y+z=1, with z≦0.5 and a thickness of 0.1-2 μm and with equiaxed or needlelike grains with size ≦0.5 μm;
- and
- an outer layer of smooth, textured, fine-grained α-Al2O3 layer with a thickness of 2-10 μm wherein the α-Al2O3 outer layer has a texture in (012)-direction with a texture coefficient TC(012) larger than 1.3.
A cutting insert for milling of grey cast iron comprising a substrate and a coating, said substrate comprising WC, 3-15 weight-% Co and ≦2 weight-% carbides of metals from groups IVb, Vb or VIb of the periodic table and said coating comprising:
- a first (innermost) layer of TiCxNyOz with x+y+z=1 and a thickness of 0.1-2 μm, and with equiaxed grains with size <0.5 μm;
- a layer of TiCxNyOz with x+y+z=1 and a thickness of 2-10 μm with columnar grains with a diameter of about <5 μm;
- a layer of TiCxNyOz with x+y+z=1, with z≦0.5 and a thickness of 0.1-2 μm and with equiaxed or needlelike grains with size ≦0.5 μm;
- and
- an outer layer of smooth, textured, fine-grained α-Al2O3 layer with a thickness of 2-10 μm wherein the α-Al2O3 layer has a texture in the (104)-direction with a texture coefficient TC(104) larger than 1.3.
A cutting insert for milling of grey cast iron comprising a substrate and a coating, said substrate comprising WC, 3-15 weight-% Co and ≦2 weight-% carbides of metals from groups IVb, Vb or VIb of the periodic table and said coating comprising:
- a first (innermost) layer of TiCxNyOz with x+y+z=1 and a thickness of 0.1-2 μm, and with equiaxed grains with size <0.5 μm;
- a layer of TiCxNyOz with x+y+z=1 and a thickness of 2-10 μm with columnar grains with a diameter of about <5 μm;
- a layer of TiCxNyOz with x+y+z=1, with z≦0.5 and a thickness of 0.1-2 μm and with equiaxed or needlelike grains with size ≦0.5 μm;
- and
- an outer layer of smooth, textured, fine-grained α-Al2O3 layer with a thickness of 2-10 μm wherein the α-Al2O3 layer has a texture in the (110)-direction with a texture coefficient TC(110) larger than 1.3.
Dependencies are inferred from the claim text.