Study on the fabrication and physical properties of cold-sprayed, Cu-based amorphous coating

Abstract

Cu-based amorphous (Cu54Zr22Ti18Ni 6) coating was produced through cold spraying as a new fabrication process. The microstructure and macroscopic properties of the amorphous coating layer were investigated and compared with those of the cold-sprayed, pure Cu coating. Amorphous powder was prepared via gas atomization, and Al 6061 was used as the substrate plate. The X-ray diffraction results showed that Cu-based amorphous powder could be successfully deposited through cold spraying sans any crystallization. The Cu-based amorphous coating layer (300-400 μm thick) had 4.87% porosity. The hardness of the Cu-based amorphous coating was 412.8 H v or 68% of the hardness of the injection-casted bulk amorphous material. The wear resistance of the Cu-based amorphous coating was found to be three times higher than that of the pure Cu coating. The results of the 3-point bending test showed that the adhesion strength of the Cu-based amorphous coating layer was higher than the pure Cu coating. The hard Cu-based amorphous particle was also observed to be able to deform soft substrate easily through particle collisions; thus generating strong adhesion between the coating and substrate. Note, however, that the amorphous coating layer unexpectedly showed lower corrosion resistance than the pure Cu coating, possibly due to the higher porosity of the cold-sprayed amorphous coating. © 2009 IOP Publishing Ltd.