TiB-based coating formation on Ti6Al4V alloy

In the present study, it is aimed to produce titanium boride layer on Ti6Al4V substrate by a simple, cheap and efficient method of pack boriding process. Pack boriding process was conducted out at 1,000, 1,100, and 1,200 degrees C in argon atmosphere for 6, 8, and 10 h to see the effect of both temperature and the time on boride layer. The presence of both TiB2 and TiB borides was confirmed by SEM (Scanning Electron Microscopy) and the XRD (X-ray diffraction analysis). SEM studies indicated that the morphology of boride layers has dense and layered nature and having a maximum layer thickness of approximately 16 mu m. The hardness of boride layer, measured by Vickers indentation method, was over 2000 HV. It was found that formation of borides has parabolic nature for process temperatures and times. Kinetic studies showed that boride layer abide the parabolic growth law. Diffusion activation energy for boron in total boride layer (TiB2 and TiB) during the pack boriding process was calculated as 77.402 kJ mol-1.