Abstract
In this study, the effect of Y2O3 addition on the quality, microstructure, and microhardness of multi-track laser-cladded Ti-6Al-4V coating using coaxial powder feeding was investigated. These parameters were characterised via dye penetration, x-ray diffractometry, scanning electron microscopy, energy dispersive spectrometry, electron probe microanalysis, microhardness measurements, and ball-on-disc tribometer. It is observed that Y2O3 addition improved the coating quality by completely eliminating the formation of pores in multi-tracked Ti-6Al-4V coatings. The microstructure of the coating without and with Y2O3 primarily consists of acicular martensite (α′-Ti). Furthermore, the continuity of original β-Ti grain boundary is broken by the introduction of Y2O3. In addition, the Y2O3 is adsorbed and pinned at the original β-Ti grain boundaries resulting in the refinement of the β-Ti grains. It is believed that the refinement in the original β-Ti grains occurs via inhibition of the movement of the grain solid–liquid interface through dragging action. This phenomenon hinders grain growth by acting as a heterogeneous nucleus rather than increasing nucleation rate because it exhibits high lattice misfit degree. Compared with the coating without the Y2O3, the microhardness and wear stability of the Y2O3-supplemented coating was improved because of grain boundary strengthening, fine-grained strengthening, addition of high hardness Y2O3, and elimination of pores.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.