Boriding behaviour of titanium alloys with different crystalline structures

ABSTRACT

The objective of this study is to investigate the boriding behaviour of titanium implant materials on the basis of their crystalline structure and chemical composition. α-type Cp-Ti, α + β type Ti-6Al-4V and β-type Ti-45Nb alloys have been borided by the powder-pack boriding technique at temperatures between 850 and 1200°C. The X-ray diffraction, GDOES and SEM analysis demonstrated that boride layers on Cp-Ti and Ti-6Al-4V alloy mainly composed of TiB₂ and TiB phases, whereas Ti-45Nb alloy consists of the mixture of TiB₂.NbB₂ and TiB phases. Boride layers on Ti-45Nb alloy grew uniformly and the highest boride layer thickness of 72.1  μm was obtained on this alloy among the others. Activation energies of boron in monolithic layer of Cp-Ti and Ti-6Al-4V alloy were determined to be 214.5 and 231.8  kJ/mol, respectively. Activation energies in monolithic and total boride layers on Ti-45Nb were determined to be 228.5 and 145.8  kJ/mol, respectively.

KEYWORDS:

• Cp-Ti
• Ti-6Al-4V
• Ti-45Nb
• powder-pack boriding
• microstructure
• growth kinetics

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Karadeniz Teknik Ãœniversitesi: [grant number 10501].