The basic direction of thermal barrier coatings (TBC) systems development is related to new materials solutions dedicated for bond-coats and ceramic insulating layers. From technological point of view this development consists mainly new conceptions in internal architecture of ceramic sublayer in the form e.g. of segmented, composite or multilayered morphology. In the case of new materials concepts the most interesting areas of investigations are related to strongly defected systems such as pyrochlore ceramic with overall formula RE2(Zr,Hf,Ce)2O7, perovskites or hexaaluminates materials of REZrO3 and (A,B)Al11O19 type respectively, or defected cluster zirconia based materials with two rare earth elements (with high cations ionic size differences) and formula ZrO2-Y2O3-RE12O3-RE22O3.

In presented article thermal properties of different types of pyrochlore material based on zirconia, hafnia and ceria of samarium are presented. Analyzed materials were synthesized by solid state reaction method form mixture of feedstock nano-sized powders of zirconia, hafnia, ceria and samaria. Synthesized materials were analyzed from its chemical and phase constituent point of view. The crystallite size was determined as well by X-ray diffraction method. Additionally the crystallite size and theirs orientations were analyzed by EBSD method. The morphological characterization of used feedstock powders was showed as well. The basic range of investigations was related to thermal parameters such as thermal diffusivity, specific heat and coefficient of thermal expansion analysis. Those data were obtained by laser flash analysis, calorimetric and dilatometric investigations respectively. On the base of those data the thermal conductivity was calculated in temperature range 25 to 1500°C. Obtained value of thermal parameters were compared to analogous data for usually used zirconia based ceramic of 8YSZ type.

The research has been supported by National Science Centre within Sonata scheme, under contract UMO-2016/21/D/ST8/01687.

Graphene based high performance coatings have been developed using a graphene powder prepared in our lab using a new pressure based exfoliation method. Three kinds of coatings were made: (i) pre-treatment coatings on steel substrates using a new patented method of functionalizing graphene. The thin five micron coating has excellent adherence and very low permeability. (ii) graphene dispersed epoxy primer whose properties appear superior than a epoxy zinc rich coating or inorganic zinc rich coating and (iii) a graphene based polyurethane top coat with superior UV blocking properties. Combining all the individual coatings as conversion coating, primer and top coat, it becomes an excellent high performance coating with very high corrosion resistance, mechanical properties and weathering resistant. Each individual coating has its independent application for example pre-treated graphene can be an excellent replacement for electrolytic coating for automobile bodies and graphene dispersed epoxy can be a good replacement for epoxy based zinc rich coating or inorganic zinc rich primers.

The effect of surface aluminizing treatment on air-oxidation behavior of equimolar FeCoNi-based alloys (FeCoNi and FeCoNiCr) was studied at 950^oC. The results showed that the oxidation kinetics of the aluminized alloys followed the two-stage parabolic rate law. The optimal aluminized parameters were to heat the alloys at 850^oC for 4 h in 63% Al₂O₃-30% (Fe-Al)-7%AlF₃ powders under an Ar-gas flow-rate of 200 cm³/min. The oxidation rates of the aluminized alloys were significantly lower than those of the untreated alloys by 3 to 5 orders of magnitude. The scales formed on the aluminized alloys consisted of an exclusive thin-layer of a-Al₂O₃ whose formation is responsible for the significant reduction of the oxidation rates with respect to the ternary and quaternary substrates.

Amorphous Hf₇B₂₃Si₂₂C₆N₄₀, Hf₇B₂₃Si₁₇C₄N₄₅ and Hf₆B₂₁Si₁₉C₄N₄₇ coatings were synthesized by reactive pulsed dc magnetron co-sputtering. These coatings possess a hardness of ~ 20 GPa and a Young’s modulus of ~170 GPa, and exhibit superior high-temperature oxidation resistance. The microstructures of the coatings annealed up to various temperatures from 1100 °C to 1600 °C in helium and in air were studied by X-ray diffraction (XRD) and transmission electron microscopy (TEM) to understand the effect of slight composition tuning on their microstructure evolution at high temperatures. All annealed films were found to have a two-layered structure composed of the original film followed by a nanocomposite oxidized surface layer involving HfO₂ nanoparticles embedded in a SiO_x-based matrix. Slight changes in the nitrogen content of the coatings were found to result in significant microstructure difference and oxidation resistance at high temperatures.