Cemented Carbide Coating

Thread cutter cemented carbide coating has physical vapor deposition (PVD) and chemical vapor deposition (CVD) two methods. The former is common used with TiN, TiCN, TiALN and its composite coating.Solid cemented carbide taps, solid carbide thread milling cutters and solid carbide cutting tools, and methods can be used as needed PVD coating. Carbide inserts the use of chemical vapor deposition (CVD) method for coating.

The cemented carbide coating had appeared in early 1960s. By chemical vapor deposition (CVD) process, the cemented carbide surface is coated with the refractory metal carbides in one or more layers (5μm ~ 13μm). Good overall performance, good toughness of the matrix strength alloy coating, surface wear-resistant, high temperature. But the coated carbide degree of sharp edge chipping resistance is less than ordinary carbide. Carbide coated inserts are widely used in ordinary steel finishing and semi-finishing and roughing. Coating material includes: TiC, TiN, TiCN, and AL2O3 composite. Carbide the gold blade CVD coating process, the common coating structure is: TiN-Al2O3-TiCN-matrix.

TiC coating has high hardness and wear resistance, oxidation resistance is also good, cutting can produce titanium dioxide film, effectively reduce the coefficient of friction and reduce tool wear. The general cutting speed can be increased by about 40%. TiC and steel is a high bonding temperature, the surface of the crystal grains finer, and rarely produce BUE cutting, suitable for finishing. The TiC coating drawback is formed between the linear expansion coefficients of the base body large difference with the substrate, a fragile decarburized layer, reducing the flexural strength of the tool. Therefore, heavy cutting, the machining of hard material or the workpiece with the inclusions, the coating is easy to crack.

TiN coating at a high temperature to form an oxide film, the smaller the friction coefficient with the iron-based material, the anti-blocking performance, can effectively reduce the cutting temperature. TiN coated blade anti-crater and flank wear ability than TiC coated inserts. It is suitable for cutting steel and material easy to stick the knife, the machined surface is less roughness, tool life is higher. In addition, the TiN coating also good thermal shock resistance. The disadvantage is that the bonding strength with the substrate is less than TiC coating, and the coating thickness when easy peeling.

TiC-TiN composite coatings: the first layer coated TiC, easy to fall off the solid matrix bonding. The second layer was coated with TiN, to reduce the friction of the surface layer of the workpiece.

TiC-AL2O3 composite coating: the first layer coated TiC, easy to fall off the solid matrix bonding. The second layer coating AL2O3 has good chemical stability and oxidation resistance of the surface layer. This composite coating like ceramic knife, as the high-speed cutting life than TiC, TiN coated inserts, while avoiding ceramic knife brittle, easily chipping shortcomings.

The single coated blade has been rarely used, most of the TiC-TiN composite coating of TiC-AL2O3-TiN composite coating.

The coated cemented carbide is a composite material; the substrate is preferably alloy strength, toughness, while the surface layer is a high hardness, high wear resistance, high temperature, low friction material. The new material is effective to improve the overall performance of the alloy, developed rapidly. Widely used in indexable carbide thread turning inserts, thread cutter.

Chinatungsten Online can provide various sizes and grades of cemented carbide cutting tools, non-standard products are also customized according to customer requirements. Welcome to consult and purchase sales@chinatungsten.com, sales@xiamentungsten.com .