Abstract: An improved coated body having a nanocrystalline CVD coating of Ti(C,N,O) is disclosed. The coating is formed using the MTCVD process and including, as part of the gaseous mixture, CO, CO2 or mixtures thereof. The use of this dopant during the coating results in a much smaller, equiaxed grain size. The method of forming the body is also disclosed.

Abstract: A coated sintered cemented carbide body includes a cemented carbide body, a first layer adjacent the cemented carbide body, the first layer including Ti(C,N) and having a thickness of from about 3 to about 20 &mgr;m, an alumina layer adjacent said first layer, the alumina layer including &agr;-Al2O3 or &kgr;-Al203 and having a thickness of from about 1 to about 15 &mgr;m, and a further layer adjacent the aluminum layer of a carbide, carbonitride or carboxynitride of one or more of Ti, Zr and Hf, the further layer having a thickness of from about 1 to 15 &mgr;m. A friction-reducing layer, including one or more of &ggr;-A12O3, &kgr;-Al203 and nanocrystalline Ti(C,N) and having a thickness of from about 1 to about 5 &mgr;m, can be adjacent to the further layer. A method to cut steel with a sintered cemented carbide body where the alumina is &agr;-Al2O3 and a method to cut cast iron with a sintered cemented carbide body where the alumina is &agr;-Al2O3.

Abstract: There is disclosed a coated body having as the outer layer a layer of &ggr;-Al2O3 deposited by chemical vapor deposition, preferably at a temperature of from 700-900° C. The &ggr;-Al2O3 layer is formed through the use of a gaseous mixture including H2S in amounts significantly higher than those presently used and at a temperature of from 700-900° C. The method is also disclosed.

Abstract: An improved coated body having a nanocrystalline CVD coating of Ti(C,N,O) is disclosed. The coating is formed using the MTCVD process and including, as part of the gaseous mixture, CO, CO2 or mixtures thereof. The use of this dopant during the coating results in a much smaller, equiaxed grain size. The method of forming the body is also disclosed.

Abstract: A coated body having a multi-layer of &kgr;-Al2O3 and or &ggr;-Al2O3 or TiN applied by MTCVD (Medium Temperature Chemical Vapor Deposition) is disclosed. The multi-layers can be interspersed with layers of Ti(C,N) which can also be applied by MTCVD. The body which is coated is preferably a cemented carbide, cermet, ceramic and/or high speed steel and may be used as a metal cutting insert.

Abstract: An improved coated body having a nanocrystalline CVD coating of Ti(C,N,O) is disclosed. The coating is formed using the MTCVD process and including, as part of the gaseous mixture, CO, CO2 or mixtures thereof. The use of this dopant during the coating results in a much smaller, equiaxed grain size. The method of forming the body is also disclosed.

Abstract: An improved coated body having a nanocrystalline CVD coating of Ti(C,N,O) is disclosed. The coating is formed using the MTCVD process and including, as part of the gaseous mixture, CO, CO2 or mixtures thereof. The use of this dopant during the coating results in a much smaller, equiaxed grain size. The method of forming the body is also disclosed.

Abstract: An improved coated cemented carbide insert for the cutting of cast iron is provided. The insert has multi-layer TiCN between the substrate and the &agr;-Al2O3 coating. The innermost portion of the TiCN layer is composed of large columnar grains while the outermost portion is of small equiaxed grains.

Abstract: An improved coated cemented carbide insert for the cutting of steel is provided. The insert has multi-layer TiCN between the substrate and the &kgr;-Al2O3 coating. The innermost portion of the TiCN layer is composed of large columnar grains while the outermost portion is of small equiaxed grains. Above the &kgr;-Al2O3, another columnar Ti(C,N) layer is applied.

Abstract: There is provided an Al.sub.2 O.sub.3 -TiN coated cemented carbide insert intended for turning of steels and especially Ca-treated steels. The alumina layer is protected by an extra thick and multilayered coating of TiN. The TiN coating is wet blasted and, for this purpose, (Ti,Al)(C,O,N) bonded to the underlying Al.sub.2 O.sub.3 layer which preferably consists of .alpha.-Al.sub.2 O.sub.3. The extra tough behavior together with increased wear resistance can be obtained by optimizing the TiN layer thickness, structure and adhesion and wet blasting the said TiN coating. This invention is characterized by the fact that the coating layers are not missing at the cutting edge of the insert.

Abstract: There is disclosed an alumina coated cemented carbide insert having improved properties for metal cutting applications. The insert has 6 to 8 layers of alumina with a total coating thickness of up to about 15 .mu.m. It has also been found that varying the number of layers can change the color of the coated insert.

Abstract: An improved multilayer alumina coated cemented carbide insert is made by depositing on the substrate a .kappa.-alumina layer, wet blasting the surface of that insert and then heat-treating the resulting insert at 900.degree. C.-1100.degree. C. for 0.3-10 hours to convert the .kappa.-alumina to .alpha.-alumina. One or more further alumina layers can then be applied.

Abstract: Improved properties of aluminum oxide water layers on cemented carbides and related substrates can be obtained by having the outermost alumina layer in the form of kappa-Al.sub.2 O.sub.3 deposited on a kappa-modification layer.

Abstract: Improved properties of aluminum oxide wear layers on cemented carbides and related substrates can be obtained by combining the two alumina polymorphs (.alpha.-Al.sub.2 O.sub.3 and kappa-Al.sub.2 O.sub.3) as multilayers. The nucleation of .alpha.-Al.sub.2 O.sub.3 and particularly kappa-Al.sub.2 O.sub.3 can be controlled by means of modification layers. According to this invention, it is thus possible to CVD-deposit an oxide multicoating layer consisting of clearly specified layers of .alpha.-Al.sub.2 O.sub.3 and kappa-Al.sub.2 O.sub.3. Preferably, .alpha.-Al.sub.2 O.sub.3 is deposited first by CVD on a TiC coated cemented carbide substrate followed by the said coating layer of kappa-Al.sub.2 O.sub.3.