Quasi-crystalline coatings, in particular the Al–Cu–Fe–Cr system, have attracted considerable attention due to the unique combination of physical and chemical properties resulting from their aperiodic atomic structure. Industrial production of such coatings requires careful control of process parameters to ensure reproducibility and high quality of the final product.
This paper examines the characteristics of a quasicrystalline Al–Cu–Fe–Cr coating obtained by plasma spraying under industrial conditions. Particular attention is paid to the microstructure, phase composition and tribological properties of the coating.
Microstructural analysis revealed a dense, well-bonded structure with characteristic quasicrystalline grains. The phase composition determined by X-ray diffraction confirmed the predominance of the icosahedral phase with a small amount of secondary phases.
A thermal spray coating of Al–Cu–Fe–Cr was applied to cookware and then examined. The coating was probably created using powders sprayed in a gas atmosphere with the stated composition of AlCu10Fe8.5Cr10.5. The resulting coating is highly homogeneous and includes an icosahedral quasi-crystalline phase. In addition, there is a second phase, which is either a decagonal quasi-crystalline structure or its close crystalline analogue.
These phases are characterized by the presence of structural defects and are apparently in an unstable state. The probable cause of this is rapid cooling during thermal spraying. A characteristic feature of the coating is a significant number of unmelted particles and the presence of microcracks uniformly distributed over its entire surface.
Tribological tests have demonstrated high wear resistance and a low coefficient of friction of the coating. These properties make it promising for use in various areas where wear protection and friction reduction are required, such as in the automotive industry and mechanical engineering.
Thus, the industrially produced quasi-crystalline Al–Cu–Fe–Cr coating has unique characteristics that open up wide possibilities for its application in various industries. Further research is aimed at optimizing the process parameters to improve the coating performance and expand its application area.
Author: D. J. Sordeletab, S. D. Widener, Y Tang, M. F. Besser
Institute: Metallurgy and Ceramics Program, Ames Laboratory, Iowa State University, Ames, Iowa 50011, USA, Department of Materials Science and Engineering, Iowa State University, Ames, IA 50011, USA, Department of Mechanical Engineering, Iowa State University, Ames, IA 50011, USA