Influence of Carbon and RE Oxides on the Crystal Morphologies in Laser Fabricated Composites
J-N. Li, Z. Wang, X-C. An, B-L. Zhang, D-F. Yan, H-C. Yu, X-C. Duan and Z. Zhang
The composite coatings containing borides and carbides were fabricated on a Ti-6Al-4V alloy by CO2 laser cladding of the Al3Ti-Cu-TiB2-C mixed powders. Microscopic analysis revealed that with decreasing of the C content, the crystals such as the titanium borides and the Ti5Si3/TiC eutectics had more time to grow up. Addition of the proper Y2O3 content would retard the growth of the crystals in a certain extent, resulting in a fine microstructure; also, it was noted that Cu was able to promote growth of the crystals in laser induced molten pool.
Keywords: CO2 laser, Ti-6Al-4V alloy, carbon, RE oxide, powder, crystal growth, microstructure, rare-earth compounds, composites