In the present study, commercial pure titanium was successfully plasma paste borided using borax paste at a temperature of 700, 750 and 800°C for 3, 5 and 7 h. The X-ray diffraction and scanning electron microscopy techniques revealed the presence of both TiB 2 top-layer and TiB whiskers sub-layer. The formation rates of the TiB 2 layer and TiB whiskers were found to have a parabolic character at all applied process temperatures. Based on the present Ti borides growth data, correspondent diffusion temperature and time, an analytical diffusion model was used to estimate boron diffusion coefficients and activation energies of the boride phases in a binary multiphase Ti-B system. Depending on the temperature and layer thickness, the activation energies of boron in TiB 2 and TiB phases were determined to be 137.55 ± 0.5 and 55.21 ± 0.5 kJ mol −1 , respectively. These values of boron activation energies for pure titanium were compared to the literature data. Nomenclature t the treatment time (s) C TiB2 up the upper limit of boron content in TiB 2 (=31.10 wt-% B) C TiB2 low the lower limit of boron content in TiB 2 (=30.10 wt-% B) C TiB up the upper limit of boron content in TiB (=18.50 wt-% B) C TiB low the lower limit of boron content in TiB (=18.00 wt-% B) C ads the adsorbed boron concentration in the boride layer (wt-%B). C 0 the boron solubility in the substrate (≈0 wt-%B) u the position of the (TiB 2 /TiB) interface or the TiB 2 layer thickness (µm) v the position of the (TiB/Ti) interface or the total layer thickness (µm) l the layer thickness of TiB (µm) k 1 the parabolic growth constant at the (TiB 2 /TiB) interface k 2 the parabolic growth constant at the (TiB/Ti) interface D TiB2 B the diffusion coefficient of boron in TiB 2 (m 2 s −1 ) D TiB B the diffusion coefficient of boron in TiB (m 2 s −1 )