Synthesis and Characterization of Carbon Nanotube (CNT) Reinforced Laser Alloyed Composite Coatings
J-N. Li, G-L. Liu, Y-S. Huo, Y-B. Zhang and C-C. Jiang
The Co5Zn21 nanoparticles (NP) and the un-melted carbon nanotubes (CNTs) were observed in the Stellite 12-Zn-TiC-CNTs-Y2O3 laser alloying composite coating on a TA7 Ti-alloy. Such coating was researched by means of a X-ray diffraction (XRD), a scanning electron microscope (SEM) and a high resolution transmission electron microscope (HRTEM). Experimental results indicated that such coating mainly consisted of the γ-Co, MxCy, Co5Zn21, TiC, and the amorphous phases. MxCy consisted of lot of the compounds, such as M23C6 (Cr23C6), M7C3 (Cr7C3), etc. CNTs were covered by lot of NP. Under the hinders of NP, CNTs were not free to grow up in such coating. Wear volume loss of such laser alloyed coating is approximately 1/13 of a TA7 alloy.
Keywords: CO2 laser, titanium alloy, Stellite, nano particles (NP), carbon nanotubes (CNTs), laser alloying, amorphous materials, nanostructures, surfaces