TY - GEN
T1 - Influence of hydrogen on phase stability and microhardness in Ti-Nb
AU - Zander, D.
AU - Kofmann, B.
AU - Eliezer, D.
AU - Gutmanas, E. Y.
AU - Abramov, E.
AU - Olson, D.
PY - 2003/12/1
Y1 - 2003/12/1
N2 - Alloying of Ti-based alloys with hydrogen is used to modify microstructure and hence microhardness. Titanium and titanium alloys have a high affinity to hydrogen and a large storage capacity. In this study, hydrogen charging was performed electrochemically in a 2:1 glycerin-phosphoric acid electrolyte at high fugacities. The objective of our present research is to investigate in detail by means of X-ray diffraction, SEM as well as TEM and microhardness the influence of hydrogen at high fugacities on phase stability as well as on microhardness in Ti-Nb (20-45 wt.% Nb) alloys. Hydrogenation of Ti-Nb was found to exhibit a significant effect on the phase stability as well as the microhardness of Ti-Nb (20-45 wt.% Nb). Hydrogenation of the near α Ti-20wt.%Nb alloy at high fugacities led to precipitation of (Ti,Nb)H x in the metastable α″ matrix and to an increase of the lattice parameter of the β-phase. The microhardness of Ti-20wt.%Nb decreased with increasing hydrogen content up to 3000 ppm. For the investigated β Ti-Nb alloys, it was found that hydrogen stabilized the investigated bcc β-phase, but destabilized the hep ω-phase. With increasing hydrogen content an expansion of the lattice constant of the β-phase occurred, followed by the formation of (Ti,Nb)Hx. The microhardness measurements for Ti-40wt.%Nb nor for Ti-45wt.%Nb showed no significant change after hydrogenation. It is known that hydrogen strongly influences the slip mechanism in the bcc-phase and assists in lowering the deformation energy, so the influence of hydrogen on the mechanism of plastic deformation of Ti-Nb is of considerable interest. The observed microstructural investigations should provide significant insight as to the microstructural mechanism through which hydrogen enhances the plasticity of Ti-Nb alloys.
AB - Alloying of Ti-based alloys with hydrogen is used to modify microstructure and hence microhardness. Titanium and titanium alloys have a high affinity to hydrogen and a large storage capacity. In this study, hydrogen charging was performed electrochemically in a 2:1 glycerin-phosphoric acid electrolyte at high fugacities. The objective of our present research is to investigate in detail by means of X-ray diffraction, SEM as well as TEM and microhardness the influence of hydrogen at high fugacities on phase stability as well as on microhardness in Ti-Nb (20-45 wt.% Nb) alloys. Hydrogenation of Ti-Nb was found to exhibit a significant effect on the phase stability as well as the microhardness of Ti-Nb (20-45 wt.% Nb). Hydrogenation of the near α Ti-20wt.%Nb alloy at high fugacities led to precipitation of (Ti,Nb)H x in the metastable α″ matrix and to an increase of the lattice parameter of the β-phase. The microhardness of Ti-20wt.%Nb decreased with increasing hydrogen content up to 3000 ppm. For the investigated β Ti-Nb alloys, it was found that hydrogen stabilized the investigated bcc β-phase, but destabilized the hep ω-phase. With increasing hydrogen content an expansion of the lattice constant of the β-phase occurred, followed by the formation of (Ti,Nb)Hx. The microhardness measurements for Ti-40wt.%Nb nor for Ti-45wt.%Nb showed no significant change after hydrogenation. It is known that hydrogen strongly influences the slip mechanism in the bcc-phase and assists in lowering the deformation energy, so the influence of hydrogen on the mechanism of plastic deformation of Ti-Nb is of considerable interest. The observed microstructural investigations should provide significant insight as to the microstructural mechanism through which hydrogen enhances the plasticity of Ti-Nb alloys.
UR - http://www.scopus.com/inward/record.url?scp=23844504076&partnerID=8YFLogxK
M3 - Conference contribution
AN - SCOPUS:23844504076
SN - 0873395018
T3 - Hydrogen Effects on Material Behaviour and Corrosion Deformation Interactions - Proc. of the International Conference on Hydrogen Effects on Material Behaviour and Corrosion Deformation Interactions
SP - 345
EP - 354
BT - Hydrogen Effects on Material Behaviour and Corrosion Deformation Interactions - Proc. of the International Conference on Hydrogen Effects on Material Behaviour and Corrosion Deformation Interactions
A2 - Moody, N.R.
A2 - Thompson, A.W.
A2 - Ricker, R.E.
A2 - Was, G.S.
A2 - Jones, R.H.
T2 - International Conference on Hydrogen Effects on Material Behaviour and Corrosion Deformation Interactions
Y2 - 22 September 2002 through 26 September 2002
ER -