Biira, SaphinaThabethe, T.T.Hlatshwayo, T.T.Bissett, H.Ntsoane, T.Malherbe, J.B.2023-04-012023-04-012020Biira, S., Thabethe, T. T., Hlatshwayo, T. T., Bissett, H., Ntsoane, T., & Malherbe, J. B. (2020). Investigating the thermal stability of the chemical vapour deposited zirconium carbide layers. Journal of Alloys and Compounds, 834, 155003. https://doi.org/10.1016/j.jallcom.2020.155003https://doi.org/10.1016/j.jallcom.2020.155003https://nru.uncst.go.ug/handle/123456789/8382The effect of thermal treatment on zirconium carbide (ZrC) layers deposited by chemical vapour deposition process was investigated using X-ray diffraction (XRD), Raman spectroscopy, nanoindention and scanning electron microscopy (SEM). The ZrC layers deposited at 1400 C (composed of 96% ZrC and 4% C) were annealed at 1500, 1600, 1700 and 1800 C for 2 h under high vacuum of 2.6 10 7 mbar. After annealing, the lattice constant and the average crystallite sizes were found to increase whereas the lattice strain and dislocation density decreased. The preferred orientation of the as-deposited layers was (220); it changed to (200) when annealed at 1500 C and 1600 C. At annealing temperature of 1700 C and 1800 C, the preferred orientation was (220) just like for the as-deposited ZrC layers. From Raman spectroscopy analysis, the ID/IG ratio reduced from 0.694 to 0.414 with annealing temperature indicating an improvement in crystallinity level and a decrease in the defects in the carbon material in the ZrC layers. The hardness of the layers was found to decrease slightly with annealing temperature from 26.4 ± 0.6 GPa to 21.3 ± 0.5 GPa. Some voids initially present in the as-deposited ZrC layers closed up and particles increased in size with annealing temperature.enAnnealing temperatureChemical vapour depositionZrC layersMicrostructural propertiesSurface morphologyArticle