Characteristics, wear and corrosion properties of borided pure titanium by pack boriding near α → β phase transition temperature

The boride layer characteristics, wear and corrosion properties of borided commercially pure titanium by pack boriding near the alpha -> beta phase transition temperature were investigated using X-ray diffraction, scanning electron microscopy, electron probe microanalysis, dry reciprocating friction tests, and electrochemical experiments in this work. The pack boriding was carried out at the temperatures of 860 degrees C, 880 degrees C, 900 degrees C, and 920 degrees C for 5, 10, 15 and 20 h. The results indicated that, in both alpha and beta phase temperatures, the boride layer is composed of the outer TiB2 layer and the inner TiB layer. The alpha -> beta phase transition temperature of commercially pure Ti in this work is in the range of 882-900 degrees C, and the growth of TiB layer can be enhanced at this temperature range. Commercially pure Ti borided at 920 degrees C for 20 h has the best wear resistance and corrosion resistance. Finally, wear and corrosion mechanisms were also discussed.