Oxide coated cutting tool
AssigneeSandvik Aktiebolag
InventorsBjörn Ljungberg, Lars-Anders Budzynski
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Abstract
According to the present invention there is provided a body at least partially coated with one or more refractory layers of which at least one layer essentially consist of α-Al2O3. Said α-Al2O3 layer consists of essentially equiaxed grains with an average grain size of <1 μm and with a bimodal grain size distribution with coarser grains with an average grainsize in the interval 0.5-1 μm and finer grains with an average grainsize of <0.5 μm. The Al2O3 layer further contains striated zones containing titanium (>5 at %) but no nitrogen or carbon. This particular microstructure is obtained by temporarily stopping the gases needed for the growth of the Al2O3 layer and introducing TiCl4.
Claims8
A cutting tool comprising a body of sintered cemented carbide, cermet, or ceramic superhard material, the body comprising a surface, and a hard and wear resistant coating on at least a portion of the surface, said coating comprising:
- one or more refractory layers of which at least one layer essentially consists of α-Al2O3, said α-Al2O3 layer having equiaxed grains with an average grainsize of <1 μm and further containing striated zones containing >5 at % titanium, but no nitrogen or carbon.
A cutting tool comprising a body of sintered cemented carbide, cermet, or ceramic superhard material, the body comprising a surface, and a hard and wear resistant coating on at least a portion of the surface, said coating comprising:
- one or more refractory layers of which at least one layer essentially consists of α-Al2O3, said α-Al2O3 layer having equiaxed grains with an average grainsize of <1 μm and further containing striated zones containing >5 at % titanium, but no nitrogen or carbon,
- wherein said Al2O3 layer has a bimodal grainsize distribution with coarser grains with an average grain size dc≦1 μm and the finer grains df in the interval 0.1-1/3 dc.
Dependencies are inferred from the claim text.