Sandvik Ab

Balzers Aktiengesellschaft

Sandvik Intellectual Property Ab

Jan Lindstrom

Christopher Chatfield

Marianne Collin

Mats Sjostrand

Mats E Sjostrand

Jan N Lindstrom

Bjorn Ljungberg

Staffan Soderberg

Christopher G Chatfield

Ingrid K Collin

Hamid Shahani

Erich Bergmann

Ingrid Reineck

Ingolf Endler

Mauro Pedrazzini

Johann Karner

Leif E Akesson

Albrecht Leonhardt

Asa K Nystrom

Christine Taschner

A method for depositing refractory alumina (A.sub.2 O.sub.3) thin layers on cutting tools made of cemented carbide, cermet, ceramics or high speed steel is disclosed. The present method is a Plasma Activated Chemical Vapor Deposition (PACVD) process in which the plasma is produced by applying a bipolar pulsed DC voltage across two electrodes to which the tool substrates to be coated are fixtured and electrically connected. In contrast to prior art methods, built-up electrical charge on non-conducting surfaces is suppressed and hence, no arcing occurs on said surfaces. This will permit stable, long-term processing, With the present method, high-quality coatings of either single phase gamma-Al.sub.2 O.sub.3 or of a mixture of gamma- and alpha-Al.sub.2 O.sub.3 phases can be deposited on cutting tools at deposition temperatures as low as 500.degree. C. When coated cemented carbide tools according to the invention are used in the machining of steel or cast iron, several important improvements to prior art produced Al.sub.2 O.sub.3 -coated tools have been observed.

Method for depositing fine-grained alumina coatings on cutting tools

Coated body, method for its manufacturing as well as its use

A sintered hard material body is at least partly coated with at least one 0.5-20 .mu.m wear resistant ceramic oxide coating being &lt;80% thicker in the edges than on the flat surfaces. The oxide coating exhibits a grain size (.O slashed.) in .mu.m for which:

Alumina-coated sintered body

A method and apparatus for coating components such as cutting tools with diamond using a microwave plasma excited gas mixture in a reactor equipped with a bowl-shaped substrate table having a concave inner surface for supporting the components to be coated. The plasma forms a plasma ball during the coating operation and the geometrical shape, configuration and position of the table is adapted to stabilize the plasma and control the shape and position of the plasma in such a way that the outer surface of the plasma conforms substantially to the surfaces of the components to be coated. The table can include a system of channels for optimized gas flow and metallic or ceramic wires or rods to control the shape and position of the plasma as well as yield additional excitation of the gas mixture. The table can include an upper rim which facilitates coupling of the plasma directly to the table. The table can include ledges, rods, compartments and/or holes for supporting the components to be coated.

Apparatus for depositing diamond coating in reactor equipped with a

The present invention relates to a method for coating a cutting insert having at least one layer of a carbide, carbonitride, oxynitride, oxycarbide, oxycarbonitride or nitride of one metal selected form the groups IVB, VB or VIB of the Periodic Table, the method comprising subjecting the insert to chemical vapor deposition and coating the insert with an epitaxial kappa-Al.sub.2 O.sub.3 layer by the hydrolysis reaction of AlCl.sub.3, H.sub.2 and CO.sub.2, the hydrolysis reaction being carried out while maintaining the content of water vapor in the gas phase during nucleation of Al.sub.2 O.sub.3 at less than 5 ppm.

CVD of Al.sub.2 O.sub.3 layers on cutting inserts

A method for coating components such as cutting tools with diamond using a microwave plasma excited gas mixture in a reactor equipped with a bowl-shaped substrate table having a concave inner surface for supporting the components to be coated. The plasma forms a plasma ball during the coating operation and the geometrical shape, configuration and position of the table is adapted to stabilize the plasma and control the shape and position of the plasma in such a way that the outer surface of the plasma conforms substantially to the surfaces of the components to be coated.

Method for diamond coating by microwave plasma

A coated body consisting of a substrate that can be decarburized during a carbide, nitride or carbonitride coating process comprising a first (innermost) carbon diffusion retarding coating of MetCO, MetCON, MetON adjacent to the substrate and a second (next innermost) wear resistant coating of MetC, MetN and/or MetCN, where Met is Ti, Hf, V, Zr, Si, B or other metals of subgroup 3-7 of the periodic table of the elements, or a mixture thereof. The intermediate coating has been found beneficial in order to reduce or even eliminate the formation of eta phase in the substrate.

Diffusion barrier coating material

The present invention relates to a body coated with at least one double layer Al.sub.2 O.sub.3 -TiC. Because the Al.sub.2 O.sub.3 -layer in contact with the TiC-layer consists of kappa-Al.sub.2 O.sub.3 or theta-Al.sub.2 O.sub.3 an improved adherence has been obtained. A further improvement of the properties is obtained if the body after the coating is heat treated for 0.3-10 hours at 900.degree.-1100.degree. C. in protecting gas atmosphere at which initially nucleated kappa- or theta-Al.sub.2 O.sub.3 is transformed to fine grained alpha-Al.sub.2 O.sub.3.

Coated cutting insert

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Kista, Sweden

Mats E Sjostrand