Sandvik Intellectual Property Ab

Sandvik Aktiebolag

Gunilla Andersson

Mikael Lindholm

Peter Littecke

Anders Jonsson

Anders Nordgren

Markus Rodmar

Mikael Lagerquist

Anders Karlsson

Katarina Dahl

Jan Kjellgren

A CVD-coated cutting tool insert with improved toughness properties having the ability to withstand high temperatures without sacrificing edge line security is disclosed. The insert coating comprises a TiCN-layer with a low tensile stress level of 50-500 MPa and an &#x3b1;-AlO-layer with a high surface smoothness with a mean Ra&#x3c;0.12 &#x3bc;m as measured by AFM-technique, obtained by subjecting the coating to an intensive wet blasting operation.

Coated cutting tool insert

The present invention relates to a cutting tool insert particularly for turning of steel comprising a cemented carbide body, a coating with a post treatment with a first, innermost layer system of one or several layers of TiCNOwith x+y+z&#x2266;1 with a total thickness of 0.7&#x2013;4.5 &#x3bc;m a second multilayer system consisting of a totally 5&#x2013;31 alternating AlOand TiCNO(x+y+z&#x2266;1), preferably &#x3ba;-AlOand TiN, the AlO-layers having an individual layer thickness of &#x3c;0.5 &#x3bc;m and the TiCNO-layers 0.01&#x2013;0.2 &#x3bc;m with a total thickness of the multilayer of 1.0&#x2013;4.0 &#x3bc;m. The multilayer is exposed along the edge line and into the rake and flank face, at least 0.02 mm, from the edge line on the rake face, preferably the contact length of the chip at most 0.9 mm, and 0.02&#x2013;0.20 mm on the flank face.

Coated cemented carbide insert

A cemented carbide has a <70 &mgr;m, preferably 10-40 &mgr;m, thick binder phase enriched surface zone containing W and Mo but depleted in cubic carbide. The overall content of Mo in the surface zone is the same as that in the inner portion of the cemented carbide. By alloying the cemented carbide with Mo, the performance has been improved particularly when used for turning at conditions causing intermittent thermal and mechanical load in stainless steel.

Coated cemented carbide cutting tool insert

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Solna, Sweden

Gunilla Andersson