Influence of CrN coating in wood machining from heat flux estimation in the tool

The influence of CrN coating on the thermal phenomena during wood composite (MDF-medium density fiberboard) peeling is investigated. The heat flux in the knife is used as the thermal indicator of the coating impact. The heat flux estimation is obtained through the resolution of the inverse heat conduction problem in the tool. The difficulty encountered in this problem comes from the great uncertainty in the sensors location and on the nonlocal measurement. The noninteger system identification method is used in order to obtain an accurate heat transfer model in the tool that rely the spatial average heat flux on the cutting edge to the temperature of the sensors embedded in the tool along the time. This average heat flux is then estimated during machining using the classical constant function specification method. The spatial variation of the heat flux on the cutting edge is reached using a finite element approach and its magnitude is adjusted with respect to the value of the estimated average heat flux.