HARDNESS AND FRATURE TOUGHNE OF PLASMA SPRAYED ZIRCONIA-CERIA-YTTRIA THERMAL BARRIER COATINGS

Abstract

Several studies have been made during the recent years to evaluate the plasma sprayedyttria partially stabilized zirconia thermal barrier coatings but less attention wereundertaken on ceria-yttria stabilized zirconia. In this study, zirconia- 20 wt% ceria-3.6wt% yttria thermal barrier coatings were produced by air plasma spraying deposited onIN 738 LC superalloy substrate. The objective of this study is to analysis the distributionof porosity, hardness and fracture toughness on the deposited coatings. Under optimumplasma spraying conditions, it is dangerous to consider the mean values of hardness andfracture toughness. The distributions of hardness and fracture toughness are highlyscattered. The Weibull distribution is the main parameter to describe the plasma sprayedcoatings hardness and fracture toughness.