High hardness combined with high resistance to mechanical loads and wear make tungsten carbide an important material to produce cutting tools, molds and dies. The limiting factor for the use of the material is the time-consuming and costly processing due to its low machinability. Chemical Vapour Deposition (CVD) diamond-coated carbide tools have shown promising results, allowing process-reliable milling of tungsten carbide as an alternative to conventional Electro Discharge Machining (EDM). In application of the tools, the occurrence of a coating flaking on the rake face has been observed in several research studies. Since the coating on the flank face stays intact and the uncut thickness is smaller than the thickness of the coating, the coating on the flank face acts as a new cutting edge and the tools remain useable. Due to the flanking of the coating, the cutting edge radius and the effective rake angle are reduced. A self-sharpening effect is created, which results in improved cutting conditions.The adhesion of the CVD diamond-coating and thus the tool life as well as the occurrence of coating flaking strongly depend on the choice of substrate material and the type of coating. The scope of the present work were therefore variations regarding the grain size of the substrate material and the structure of the coating. In addition, the potential of a recreation of the coating flaking by removing the coating on the rake face using a laser was examined. The laser-treatment was intended to create a more homogeneous cutting edge topography compared to the random flaking of the coating and thus further improve the cutting conditions.Orthogonal cutting tests were performed to properly study the mechanisms of chip formation during the machining of tungsten carbide with the different tool concepts. The test setup allowed the evaluation of the thermomechanical process load in dependence of the cutting length. Cutting force, temperatures of the cutting tool and chip formation were measured in situ by means of dynamometer, thermal imaging and high-speed video recordings. The tool condition was captured and analyzed with microscopic images.In the experiments, regardless of the tool concept selected, a coating flaking on the rake face occurred, which resulted in a reduction of the thermal and mechanical tool load. The laser treatment improved the stability of the cutting conditions. Thermal and mechanical load were lowered, and the scatter of the measured values decreased. In the comparison of the tool concepts, the grain size of the substrate material was identified as a critical factor influencing tool life. Irrespective of the coating selected, the tools with coarser-grained substrate material exhibited a longer service life due to improved coating adhesion. For the tested coating systems, no discernible influence of the tool life could be identified.