Wear monitoring of protective nitride coatings using image processing

✍ Scribed by Inge L. Rasmussen; M. Guibert; M. Belin; J.-M. Martin; N.J. Mikkelsen; H.C. Pedersen; J. Schou

• Publisher: Elsevier Science
• Year: 2010
• Tongue: English
• Weight: 505 KB
• Volume: 204
• Category: Article
• ISSN: 0257-8972
• DOI: 10.1016/j.surfcoat.2009.09.004

✦ Synopsis

A double-layer model system, consisting of a thin layer of tribological titanium aluminum nitride (TiAlN) on top of titanium nitride (TiN), was deposited on polished 100Cr6 steel substrates. The TiAlN top-coatings were exposed to abrasive wear by a reciprocating wear process in a linear tribo-meter with up to 10 5 repetitive cycles, eventually leaving the embedded TiN signal layer uncovered at the bottom of the wear scar. The worn surface was characterized by subsequent image processing. A color detection of the wear scar with the exposed TiN layer by a simple optical imaging system showed a significant increase up to a factor of 2 of the relative color values from the TiAlN top layers to the embedded TiN signal layers. This behavior agrees well with the results of optical reflectance detection experiments with a red laser on the same system. Thus we have demonstrated that image processing by color detection is a potential technique for early warning or determination of residual thickness of tribological tool coatings prior to complete wear.