## 4 Conclusions  
Premature chipping of circular saws due to the lower toughness of their up-sharp cutting edges has been a critical issue in the wood processing industry for many years.  
This project characterized the benefits of applying variable engineered micro-geometry and surface coating technology on WC-Co carbide inserts mounted on circular saws. The objective was to improve the wear resistance of saws used in primary wood processing. The mechanical and tribological characterization of CrN/CrCN/DLC, CrN/AlTiN, CrN/CrCN and CrCN/TiSiCN multilayer coatings on WC-Co substrates showed that CrN/CrCN coating offered the best properties in terms of wear resistance and adhesion to the substrate. The results revealed that variable engineered micro-geometry combined with CrN/CrCN coating imparts significant improvements in the wear resistance of circular saws utilized in primary wood processing. Compared to the coated saw without edge modification and the uncoated saw with edge modification, the wear rate of the coated saw with edge modification decreased by 46% and 16%, respectively, after 480 min of sawing. Those values reached 73 % and 41%, respectively after 960 min of utilization in a mill. Furthermore, vari  
Figure 28: SEM micrographs of the defects on the cutting edges (clearance face view): (**a–c**) saws #2, 4, and 6, respectively after 480 min of sawing and (**d–f**) saws #2, 4, and 6, respectively after 960 min of sawing.  
able engineered micro-geometry paired with multilayer CrN/CrCN coating significantly reduced the tendency of the carbide tips to chip, to sustain breakage at their corners and to suffer from abrasive wear. This improvement has a major role in maximizing fiber recovery in the wood industry, contributing to significant cost savings, possible improvement of sawmill revenues, and process reliability.  
The present research lays the groundwork for subsequent studies to optimize the size of edge preparation applied on the cutting edges of the saw teeth. Optimization of the coating parameters and chemical composition of the layers could likely become another interesting avenue for future work. Moreover, reduced or delayed wear will more than likely result in lower sawing variations.  
Conceptualization, M.T., W.S., B.U., R.G., R.E.H. and C.B.; Methodology, M.T., W.S., B.U., R.G., R.E.H. and C.B.; Software, M.T.; Validation, M.T., B.U., R.G. and R.E.H.; Formal Analysis, B.U., R.G. and R.E.H.; Investigation, B.U., R.G. and R.E.H.; Resources, W.S., B.U. and R.G.; Data Curation, M.T.; Writing--Original Draft Preparation, M.T.; Writing--Review and Editing, W.S., B.U., R.G., R.E.H. and C.B.; Visualization, M.T.; Supervision, R.E.H. and C.B.; Project Administration, C.B.; Funding Acquisition, R.E.H. and C.B. All authors have read and agreed to the published version of the manuscript.  
The financial support for this project was provided by Natural Sciences and Engineering Research Council of Canada (NSERC) and FPI Innovations through a Cooperative Research and Development grant (project #CRDFJ-518967-17).  
Not applicable.  
The data presented in this study are available on request from the corresponding author. The data are not publicly available due to on-going research.  
The authors hereby thank [PERSON] (Universite Laval) and [PERSON] (FPI Innovations) for their technical assistance. The authors appreciate Aurora Scientific Corp. for the coating deposition of the samples, [PERSON] as technical director and [PERSON] as general manager of this company for their invaluable guidance. The authors would also like to thank Bois Daaquam Sawmill (Division St-Pamphile) for their valuable cooperation.  
The authors declare no conflict of interest.