Coated cemented carbide inserts
AssigneeSandvik Intellectual Property AB
InventorsSusanne NORGREN, Kenneth Westergren
Life of this patent
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Abstract
The present invention relates to cutting insert for dry milling of hard cast steel with a hardness of from about 50 to about 65 HRC comprising a substrate and a coating. The substrate has a hardness of from about 1900 to about 2100 HV3, with a negative chamfer and an edge rounding of 0 (sharp) to about 40 μm. The coating comprises a homogeneous AlxTi1-xN-layer with x equals from about 0.6 to about 0.67 and a thickness of from about 1 to about 3.8 μm. The invention also relates to a method of making as well as the use of the inserts.
Claims11
Cutting insert comprising a substrate and a coating wherein
- the substrate has a from about 8 to about 20° negative chamfer with a width of from about 0.1 to about 0.3 mm and an edge rounding of 0(sharp) to about 40 μm and a composition of from about 5.4 to about 6.3 wt-% Co, from about 0.4 to about 0.8 wt-% Cr, from about 0.01 to about 0.05 wt-% Ti+Ta with a weight ratio Ti/Ta of from about 1.0 to about 1.7, and balance WC with as sintered Hc-value of 27-35 kA/m, CW_Cr of from about 0.75 to about 0.95 and a hardness of from about 1900 HV3 to about 2100 HV3 and
- said coating comprises a homogeneous AlxTi1-xN-layer where x equals from about 0.6 to about 0.67 and a thickness of more than about 1 μm but less than about 3.8 μm.
Method of making a coated cutting tool insert of a cemented carbide substrate and a coating comprising providing a substrate using conventional powder metallurgical techniques milling, pressing and sintering with a from about 8 to about 20° negative chamfer with a width of from about 0.1 to about 0.3 mm and an edge rounding of 0(sharp) to about 40 μm with a composition of from about 5.4 to about 6.3 wt-% Co, from about 0.4 to about 0.8 wt-% Cr, from about 0.01 to about 0.05 wt-% Ti+Ta added as TaC and TiC or mixtures of these with a weight ratio Ti/Ta of from about 1.0 to about 1.7 and balance WC with as sintered Hc-value of from about 27 to about 35 kA/m, CW_Cr of from about 0.75 to about 0.95 and a hardness of from about 1900 to about 2100 HV3 and
- depositing a coating comprising a homogeneous AlxTi1-xN-layer where x equals from about 0.6 to about 0.67 and a thickness of more than about 1 μm but less than about 3.8 μm by cathodic arc evaporation using a target material of a TiAl-alloy of suitable composition, in an N2 gas atmosphere.
Dependencies are inferred from the claim text.