Widely Applied Scratch Test

     The scratch test has become one of the most widely applied methods to evaluate coating  adhesion at present. Over the past two decades, this technique is extensively used to assess the  adhesion of PVD/CVDdeposited superhard nanocomposite coatings, which usually exhibit  a high residual stress at the coating/substrate interface.

    
    Moreover, the scratch test is an essential tool for quality control of materials used in wear/abrasive environment, allowing us to detect premature adhesive/cohesive failure of coatings in real-life applications.
  
    The process of scratching is carried out in a controlled and monitored manner to observe adhesive or cohesive failures. In this study, different coatings were tested and compared using Multi-Functional Scratch Tester to showcase the capacity of the instrument and investigate the  behaviors of different coatings during the scratch tests.

    The scratch test gives very reproducible quantitative data that can be used to compare  the behavior of various coatings. The critical loads depend on the mechanical strength(adhesion,   cohesion)of a coating-substrate composite but also on several other parameters: some of them are directly related to the test itself, while others are related to the coating-substrate system.