Microstructure and physico-chemical properties of a thermally sprayed coating depend on the dynamics of the particles interacting with the spray jet. According to the process used (plasma; flame; etc.); porosity and phase composition could be different. This is especially the case for electrical properties. In this study; different spray processes (APS and HVOF) were investigated to spray Half Heusler powders type p and n. For that; the thermoelectric powder of Hf20Zr75Ti05CoSb80Sn20 (p-kind) and Hf60Zr40NiSn98Sb02 (n- kind) were selected due to their highly interesting electrical properties. The spray processes were evaluated through the measures of coating compositions and mechanical properties. A coating has only be get with plasma spray processes. The results revealed significant modifications in coating properties (atomic mass of elements; porosity) due to the operating parameters of plasma spray processes (F4MB or cascaded torch; plasma gas; etc.).

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