Experiments for estimation of influence of microplasma parameters in ZrO 2 – coating properties were performed with using of fractional-factorial design of the experiments. Regression equations for determination of the parameters significance and a selection of conditions for a deposition of coatings with specified properties were obtained. Possibility of deposition of ZrO 2 - Y 2 O 3 coating with tetragonal phase content 90 wt.% and more without cubic phase content by microplasma spraying was shown. Conditions of microplasma ZrO 2 -coating spraying with high content of tetragonal phase (93-95%) and porosity (1,3-1,8%) were established. Measurement of microplasma sprayed ZrO 2 -coating spots has established that the spots have an elliptical shape. Size of major and lateral axis (and also sprayed hill altitude) depends on spray parameters, mainly on amperage and spray distance. Microplasma sprayed ZrO 2 -coating can be applied for repair of small local defects on thermo barrier coatings and a deposition of zirconia electrolyte layer in solid oxide fuel cell.

Hydroxyapatite (HA) coatings were deposited onto titanium alloy substrate using the microplasma spray (MPS) technique. The fractional-factorial experiment design method was employed to study the relationships between MPS parameters (amperage, plasma gas flow rate, spray distance and powder rate) and characteristics of HA coatings (microstructure, morphology, content of crystalline and amorphous phases, texture). Influence of coating thickness and the deposited coating heat treatment were evaluated also. The results show some peculiarities of HA coating formation in conditions of microplasma spraying process.