Chemical vapour deposition (CVD) is a widely utilized technique in industry, particularly venerated for its precision and reliability in producing hard ceramic materials. In this study, a gas mixture comprising BCl3-CH4-H2 was employed to deposit boron carbide (B4C) onto a graphite substrate to investigate the substrate temperature-dependent physicochemical, mechanical, and electrical properties of the B4C. The phase compositional and vibrational characteristics of the B4C were thoroughly assessed using X-ray diffraction (XRD) and micro-Raman spectroscopy techniques, respectively. The field-emission scanning electron microscopy (FE-SEM) images reveal a morphological transition from murataite to triangular flakes, accompanied by noticeable grain expansion with growing substrate temperature. Additionally, energy-dispersive X-ray spectroscopy (EDS) indicates a consistent trend of increasing boron concentration and decreasing carbon concentration with rising substrate temperature. Consequently, variations in substrate temperature notably tune the deposition rate, mechanical and electrical properties of B4C. The deposition rate at 1200 °C was 1476 μm/h. Whereas, the material hardness and electrical conductivity of the CVD deposited B4C were found to be 3166 HV and 18.358 Ω-1cm-1, respectively. The present study highlights the importance of high-temperature CVD growth of the B4C for industrial applications.