Electrodeposition of titanium diboride from oxide based melts

An alternative electrochemical co-deposition method was introduced for the growth of TiB2 from the formulated, environmentally friendly, oxide-type electrolyte containing both titanium and boron ions. The depositions of TiB2 were carried out on nickel substrates at various current densities (50–150mA/cm2), temperatures (800–1000°C), and durations (30–360min). The stoichiometric TiB2 formations at all applied process conditions were confirmed by thin film X-ray diffraction (XRD) method. Scanning electron microscopy (SEM) studies revealed that the thickness and morphology were highly dependent on the electrolysis parameters. The most compact, continuous and adherent TiB2 layers were achieved to form at the optimized settings, i.e. 70mA/cm2 and 850°C at which the thickness increased from 3μm to 40μm with increasing electrolysis time. Vickers micro-indentation tests conducted on the cross section of 120min electrodeposited samples showed that the grown TiB2 layer was as hard as 3000±200HV. The co-deposition mechanism for the formation of TiB2 was also suggested with possible reactions. •An alternative electrodeposition method was introduced for TiB2 growth.•Ti and B were co-deposited from the environmentally friendly electrolyte to form TiB2.•A compact, 40μm thick TiB2 layer was grown after 240min at 850°C and 70mA/cm2.•The grown TiB2 has the hardness value as high as 3000±200HV.•The diffusion zone (DZ) formation was seen with the hardness of 1000±100HV.