CVD Ti(B,C,N) coated inserts for milling of titanium alloys

Chemical vapor deposition (CVD) is commonly used to synthesize TiB 2 coatings on industrial scale. TiB 2 coatings are unique among CVD coatings, since they exhibit compressive residual stress while CVD coatings usually exhibit tensile residual stress. That is one but not the only reason why these coatings pose various highly interesting scientific questions. Also, the correlation of deposition parameters and microstructure is not fully understood yet, which makes the development of multilayer-structures or the introduction of additional elements a challenge.

CVD Ti_1-xAl_xN coated inserts: exploration of application fields

While the growth of Ti _1-xAl _xN using physical vapor deposition is state-of-the-art since decades, the synthesis of Ti _1-xAl _xN using chemical vapor deposition is still in its infancy. CVD Ti _1-xAl _xN coatings exhibit completely different microstructures compared to PVD Ti _1-xAl _xN, which results in entirely different properties and thus, different application fields are conceivable. The controlled deposition and tailoring of microstructure of CVD Ti _1-xAl _xN as well as the implementation of additional elements is still highly challenging.

CVD α-Al₂O₃ coated inserts for turning of steel and cast iron
Chemical vapor deposited (CVD) α-Al₂O₃ coatings are typically grown on a substructure consisting of a TiN diffusion barrier layer, a TiCN base layer and very thin bonding, oxidation and nucleation layers. Each of these layers influences the growth of the Al₂O₃ top layer. Consequently, the fundamental relationships between deposition process and coating microstructure will be in the focus of investigation. Another topic will be the introduction of additional elements. On the one hand, the feasibility of the introduction of additional elements with respect to available precursors and process control will be investigated. On the other hand the influence of additional elements on the microstructure and consequently on the coating properties and cutting performance will be evaluated.

CAE nitride coated tools for milling and turning of steels

Ti_1-xAl_xN-based coatings have been deposited using cathodic arc evaporation (CAE) since decades. However, there is still potential for further improvements for example by optimizing the coating composition and architecture. In addition, new alternative coating materials like Cr_1-xTa_xN will be studied.