Yttria-stabilized zirconia–alumina composite sintering temperature effect on thermal diffusivity

Yttria-stabilized zirconia (YSZ) is one of the most common materials used for a ceramic top coat in the thermal barrier coating (TBC). The high operating temperature used in the gas turbine engines causes the stress between the top coat and the bond coat. The stress relaxation can be assured by modifications of YSZ. Hence, studies on how to modify the chemical and phase composition of these coatings are still conducted. The laser flash analysis was used to determine the thermal diffusivity of composite mixture of 8 mol% yttria-stabilized zirconia with α-Al 2 O 3 in the range of temperatures between 20 and 1100 °C. The powders were prepared with 5 and 25 mass% Al 2 O 3 addition to 8YSZ. The particle size distribution was done for each powder to analyse the grain size after milling of the α-Al 2 O 3 with 8YSZ in the ball mill. The density of each powder was measured in the helium pycnometer. The disc-shaped samples were produced by pressing using an isostatic press and then sintered at various temperatures: 1000, 1200, 1400 and 1600 °C.