Development of Innovative Iron Alloy Thermal Barrier Coatings for Low Temperature Applications

For energy conversion systems, such as internal combustion engines, the improvement of the efficiency is one of today’s major challenges. In previous studies the usage of thermal barrier coatings (TBC) on pistons, valves and cylinder heads have been reported advantageous regarding the thermal efficiency and fuel consumption. Due to the tribological loads that act in combination with combustion temperatures on the cylinder liner novel TBCs are required for this system. Within this presentation the manufacturing of innovative, highly amorphous iron alloy coatings, so called bulk metallic glasses, is introduced. The amorphous states of three experimental feedstock materials are analyzed by X-ray diffraction prior to deposition and compared with the morphology of the coatings, deposited by HVOF-technology with different standoff distances and oxygen-fuel ratios using these feedstock materials. The thermal diffusivity of the coatings determined by laser flash method is correlated to coating morphologies.