Micro-abrasive wear of DC and pulsed DC titanium nitride thin films with different levels of film residual stresses

In this work, six specimens with titanium nitride (TiN) thin films and cemented carbide (WC-Co) substrates were analyzed in terms of their micro-abrasive wear behavior. These specimens were obtained from a previous work, in which film depositions were conducted varying parameters such as bias (0, − 50 or − 100 V), type of target power (DC or pulsed DC) and, in the cases where substrate bias was zero, substrate condition (ground or floating). As a result, the level of film residual stresses varied from specimen to specimen, in the range from 4 to 11 GPa (compressive). In this work, micro-abrasive tests were run on these six specimens, using balls of AISI 1010 steel and an abrasive slurry with distilled water and silicon carbide particles with average particle size of 5 μm. Results were analyzed in terms of the wear mechanisms observed at the worn surface and also in terms of the wear resistance, characterized by the wear coefficient (k). Trends indicate a decrease in film wear rate with an increase in the value of film residual compressive stresses, as long as the adhesion was not impaired. Different values of film wear coefficient (kc) were calculated for specimens obtained with ground and floating voltage substrates, although similar values of film residual stresses were measured in both cases.