Effect of Y2O3 on the Microstructure of an Ni-B Amorphous Alloy Reinforced Laser Clad Coating on a Titanium Alloy
Y-J. Li, N. Wu and D-S. Zheng
Laser cladding of the Fe3Al+Ni/Cr/C+TiB2/Al2O3 pre-placed powders on Ti-6Al-4V alloy substrate can form a Ni-B amorphous alloy reinforced coating. With the addition of Y2O3, the Al-Ni-Y amorphous alloy was formed in the laser clad coating, which improved the wear resistance of the Ti-6Al-4V alloy. X-ray diffraction (XRD) results revealed that during the cladding process, Y2O3 can react with Ni and Al, leading to the formation of the Al-Ni-Y amorphous alloy, and the Fe3Al/Ti3Al intermetallic compounds were surrounded by the amorphous alloy. The microhardness of the Al-Ni-Y amorphous alloy reinforced coating was 4 to 5 times higher than that of the Ti-6Al-4V alloy due to actions of the Al-Ni-Y amorphous alloy and the fine TiC-TiB2 precipitates.
Keywords: CO2 laser, laser cladding, titanium alloy, Ti-6Al-4V, amorphous materials, coatings, rare earth compounds, microhardness