Physicochemical analysis of Ti-Si-B powder aalloys

Titanium alloys of Ti-Si-B system were manufactured by blended elemental powder method using Ti, Si and B powders as starting materials. It was found that uniaxial and isostatic pressing followed by hot pressing at around 1000°C, for 20 minutes, provided good densification of such alloys. The physicochemical studies were performed by means of scanning electron microscopy, X-ray diffraction, atomic force microscopy and microindentation/wear tests. The investigations revealed a multiphase microstructure formed mainly by α-titanium, Ti6Si2B, Ti5Si3, TiB and Ti3Si phases. The phase transformations after pressureless sintering at 1200°C was also studied by X-ray diffraction for the Ti-18Si-6B composition. As stated in some other researches, these intermetallics in the α-titanium matrix provide high wear resistance and hardness, with the best wear rate of 0.2 mm3/N.m and the highest hardness of around 1300 HV. © (2012) Trans Tech Publications, Switzerland.

Palavras-chave

High-energy ball milling, Sintering, Titanium alloys, Blended elemental powders, High wear resistance, Isostatic pressing, Micro indentation, Multiphase microstructure, Physico-chemical analysis, Physicochemical studies, Pressureless sintering, Wear rates, Atomic force microscopy, Ball milling, Hardness, Hot pressing, Intermetallics, Scanning electron microscopy, Silicon, Titanium, Titanium compounds, X ray diffraction