Authors: G Skordaris
Publish Date: 2014/07/22
Volume: 23, Issue: 10, Pages: 3497-3504
Abstract
Fatigue damage of the nanocrystalline diamond coating NCD bonding to the cemented carbide substrate develops when repetitive impact loads are applied onto the film Thus the highly compressive residual stresses of a NCD film are released leading to its lifting from the substrate bulge formation The present paper deals with the analytical description of the progressive failure of the NCD coatingsubstrate interface under repetitive impacts In this context an advanced 3Dfinite element analysis model was developed for the dynamic simulation of the inclined impact test using the LSDYNA software This model considers the high thermal compressive residual stresses developed in the NCD coating structure during cooling from chemical vapour deposition process temperature to ambient one The fatigue failure of the NCD coatingsubstrate interface is associated with a critical shear failure stress SFLS The determined SFLS represents the maximum operational stress permitted in the NCD filmsubstrate interface in order to avoid the coating detachment initiation According to the results obtained the successive impacts lead to a progressive weakening of the initial filmsubstrate interface strength depending upon the pretreatments prior to the NCD coating deposition
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