Effect of indentation conditions on the cracking behavior of a FeCrBSi coating

A detector combining indentation method and acoustic emission (AE) technique was developed for evaluating the bonding strengths of sprayed coatings. In order to study the effect of indentation conditions on cracking failure behavior of sprayed coating, FeCrBSi coating was prepared by plasma spraying technique. The AE signals during indentation test were abstracted and investigated. The morphologies of indented samples were observed by scanning electronic microscopy (SEM). The results indicate that indentation equipment can induce the cracking failure of coating and AE technique can define the critical statues. The test by interior load was feasible and accurate for evaluating the bonding strength. The key influential factor of indenter lied in the contact area between indenter and coating. The loading rate had little effect on AE signal. The loading conditions were optimized to use diamond indenter with interior load and a loading rate of 100 pulses per second.