TY - JOUR
T1 - Extreme hardening of titanium with colossal interstitial contents of nitrogen and oxygen
AU - Kværndrup, Frederik B.
AU - Kücükyildiz, Ömer C.
AU - Winther, Grethe
AU - Somers, Marcel A. J.
AU - Christiansen, Thomas L.
PY - 2021
Y1 - 2021
N2 - Homogenous thin foils of titanium with nitrogen and oxygen in
interstitial solid solution were characterized with X-ray diffraction,
light optical microscopy and electron backscatter diffraction. Samples
covering the broad solubility ranges of O and N were synthesized. The
mechanical properties were assessed using nanoindentation and related to
the interstitial content, h.c.p. lattice expansion and grain
orientation. Effects of surface pile-up and sink-in during
nanoindentation were adequately accounted for, yielding hardness and
indentation modulus values for nearly the full range of concentrations,
finding consistency with theoretical expressions and very limited
literature values. The hardening/strengthening achieved by colossal interstitial alloying of O and N correlates with the change in c/a ratio of the h.c.p. Ti lattice as caused by interstitial occupancy.
AB - Homogenous thin foils of titanium with nitrogen and oxygen in
interstitial solid solution were characterized with X-ray diffraction,
light optical microscopy and electron backscatter diffraction. Samples
covering the broad solubility ranges of O and N were synthesized. The
mechanical properties were assessed using nanoindentation and related to
the interstitial content, h.c.p. lattice expansion and grain
orientation. Effects of surface pile-up and sink-in during
nanoindentation were adequately accounted for, yielding hardness and
indentation modulus values for nearly the full range of concentrations,
finding consistency with theoretical expressions and very limited
literature values. The hardening/strengthening achieved by colossal interstitial alloying of O and N correlates with the change in c/a ratio of the h.c.p. Ti lattice as caused by interstitial occupancy.
KW - Titanium
KW - Gaseous oxidizing
KW - Gaseous nitriding
KW - Vacuum homogenization
KW - Transmission X-Ray diffraction
KW - Rietveld refinement
KW - Nanoindentation
KW - Electron backscatter diffraction
KW - Ti-O system
KW - Ti-N system
KW - Interstitial solutions
KW - Mechanical properties
U2 - 10.1016/j.msea.2021.141033
DO - 10.1016/j.msea.2021.141033
M3 - Journal article
JO - Materials Science and Engineering: A - Structural Materials: Properties, Microstructure and Processing
JF - Materials Science and Engineering: A - Structural Materials: Properties, Microstructure and Processing
SN - 0921-5093
M1 - 141033
ER -