The popular PVD coating process is to separate atoms from a Ti target or a TiAl target as a cathode by arc discharge and then deposit on the surface of the tool to form a coating. This method was first applied to nitride coatings. In order to obtain a smooth coating surface, began using the reactive magnetron sputtering process, that is, in the coating reaction chamber to generate argon plasma, under the action of an electric field, the ions move toward the target direction of acceleration, the metal atoms from Sputtered target, and then deposited on the tool surface. The key here is to properly control the process so that finally a crystalline rather than an amorphous coating is grown on the tool surface.
A major disadvantage of PVD nitride coatings such as TiN, TiCN or TiAlN is that their heat resistance is significantly lower than that of CVD Al2O3 coatings, which are difficult to withstand high cutting temperatures in use, limiting their range of use . As the rake face is mainly in the friction and chemical wear process, will lead to crater wear, oxidative wear or plastic deformation, so ordinary PVD coating is almost impossible to withstand this wear and tear. Therefore, the goal of developing a new coating is set to: Transplant the advantages of a CVD coating into a PVD coating. Therefore, the logical conclusion is that the development of PVD Al2O3 coating.
PVD-Tiger coating combines the advantages of CVD and PVD coating
The “PVD-Tiger” coating is also produced at high temperatures, expanding the application of this PVD coating. The reason why the new coating can be put on the market, because of the new process, which is based on reactive magnetron sputtering process.
PVD-Tiger is a composite coating whose main coating species is TiAlN and Al2O3. In order to easily identify tool wear marks, the tool surface is coated with a layer of yellowish zirconium nitride (ZrN). The ZrN coating on the rake face of the insert is removed by post-coating (spray treatment) to reveal a black Al2O3 coating that is in sharp contrast to the yellow ZrN coating on the flank. The advantage of this process is that it increases the smoothness of the cutting edge and rake face, reduces the friction and makes this two-color coated blade the main feature of the PVD-Tiger blade. CALLOY introduced a series of blade grades, cutting the level of processing reached an unprecedented height. This innovative high-tech tool material combines the advantages of CVD and PVD: high heat resistance and excellent toughness.