Thermal Stability of Thermophysical Properties of Multiphase Fe-Al Intermetallic / Oxide Ceramics Coatings Deposited by Gas Detonation Spraying

While depositing Fe-Al intermetallic powders applying a gas detonation spraying a certain coating structures containing oxide ceramics are created. These structures exhibit both extreme mechanical resistance and unusual thermophysical properties (TP) also. One of such property is relatively low thermal conductivity. A possible application as thermal barrier coatings needs precise determination of TP dependence on temperature and resistance of the coating structure to temperature exposition. At present study TPs were investigated for a coating produced from Fe-Al intermetallic powder in a course of complex measurements including DSC analyses, laser flash thermal diffusivity measurements, dilatometric studies complemented with microstructural analyses. The study resulted in full characterization of the investigated structure TPs: density, thermal expansivity, heat capacity and thermal conductivity. During thermal analyses interesting phenomena concerning thermal resistance to the temperature exposition of the investigated coating were revealed. The obtained results complement rather sparse literature data on TPs in that subject and contribute to better understanding of GDS process technology and intermetallic/oxide structures property understanding.

Acknowledgment: This study was supported by National Science Centre, Poland, Research Project No. 2015/19/B/ST8/02000