Thermophysical properties of selected powders for thermal barrier coatings

Purpose: Plasma-sprayed thermal barrier coatings often have the problems of spallation and cracking in service owing to their poor bond strength and high residual stresses. Functionally graded thermal barrier coatings with a gradual compositional variation from heat resistant ceramics to fracture-resistant metals are proposed to mitigate these problems. Design/methodology/approach: The results of measurements of thermal diffusivity by using one of the most modern experimental sets LFA 427 (Laser Flash Apparatus) produced by Netzsch Company. In order to measure the specific heat cp(T) and density p(T), two methods of termogravimetry analysis were used STA 449 Jupiter F3 Netzsch Company and gas displacement density analyzer AccuPyc II 1340 Micromeritics Company. Research limitations/implications: This paper presents the results of measurements of thermal diffusivity coefficient as a function of temperature for Sulzer powders, AMDRY 997, AMDRY 365C, METCO 45C NS, METCO 202 NS, METCO 204 NS. Practical implications: Optimal technical and technological parameters of powders for thermal barrier coatings have been selected. Originality/value: The presented method undoubtedly develops new possibilities for thermal barrier coatings.