Effect of loading rate and holding time on hardness and Youngʹs modulus of EB-PVD thermal barrier coating

The effect of the loading rates and duration of holding periods at the maximum load on hardness and Youngʹs modulus in thermal barrier coatings fabricated by the electron beam physical vapor deposition process has been studied using an ultra-micro-indentation technique. The indentation tests were carried out with three different loading rates and durations of holding time at a maximum load. The average hardness of the coating significantly increased with increasing loading rate, in contrast, it slightly decreased with holding time. However, a substantial decrease in Youngʹs modulus was observed with the increase in loading rate. A slight increased Youngʹs modulus was found with an increase in holding time. The different dependences of both the hardness and Youngʹs modulus on loading rate and holding time were associated with creep deformation occurring during indentation testing.