SOLAR FURNACE : THERMAL SHOCK BEHAVIOUR OF TIB 2 COATING ON STEEL

The 37MnSi5 steel samples were coated by TiB2 ceramic using electro spark deposition. Then the thermal shock behavior of coated and uncoated steel samples was observed using 5kW vertical solar furnace at Plataforma Solar de Almeria, Spain. The microstructure and micro hardness of the samples were observed before and after solar shock treatment. It was observed that used coatings due to good thermal conductivity lowers the maximal temperature observed in steel substrate thus enabling better dissipation of the maximum temperature into the steel sample. Together with good resistance to various chemicals also at higher temperature it seems that TiB2 is promising for surface coatings of solar heat receivers made from high temperature steels.