Fabrication of Nanostructure Composites in Functionally Graded Coatings with Supersonic Free-Jet PVD
Graded Al/AlTi and Al/Al-Si coatings are prepared by depositing nanoparticles with supersonic free-jet PVD (SFJ-PVD). The SFJ-PVD has been developed as a new coating method in which a coating film is formed by depositing nanoparticles with very high velocity onto a substrate. The high velocity of nanoparticles is produced by the supersonic gas flow of inert gas. A smooth, compact and defect-free microstructure is formed both at the interface between substrates and coating films and inside the coating films. The microstructures of Al/AlTi and Al/Al-Si coating films have very fine grain size. Mixing Ti and Al nanoparticles by depositing them onto a substrate produces in-situ syntheses of g-TiAl and a2-Ti3Al intermetallic compounds on the substrate. It is confirmed with nano-indentation hardness tester that graded coatings have graded hardness corresponding to the gradation of composition.
Omer Van der Biest, Michael Gasik, Jozef Vleugels
A. Yumoto et al., "Fabrication of Nanostructure Composites in Functionally Graded Coatings with Supersonic Free-Jet PVD ", Materials Science Forum, Vols. 492-493, pp. 341-346, 2005