Various combinations of tool materials and surface generation processes were evaluated with respect to PVD coating adhesion.
On simple geometries the only adhesion problems were related to
- dissolving of the Co binder in carbide and cermet during cleaning
- the bad adhesion of the coating on the amorphous regions in the EDMed surfaces
- a rather short ion etching step after heating.
These problems could be solved.
Typical upscaling problems are related to:
- inhomogeneous coating thickness
- chipping of sharp edges
- cleaning of complex geometries
- heating and ion etching of complex geometries
- softening of the mould steel due to exceeding the annealing temperature
For the cutting and deep drawing application promising results were presented which must enhance the industrial implementation of PVD coating technology. The findings of this project related to surface generation and pretreatment will be fit in a standard methodology so that PVD coated tools will be of a better quality.
It is clear that all different steps are important and have to be carried out with a high quality level. The success of a coated tool in its industrial application can only be guaranteed if surface generation, cleaning and coating deposition are executed in an optimal way. This can only be realised if collaboration between tool maker, job-coater and end-users becomes daily practice.