TY - GEN
T1 - Improvement of mechanical properties in Ti alloys using heterogeneous elemental distribution
AU - Emura, Satoshi
AU - Min, Xiaohua
AU - Ii, Seiichiro
AU - Tsuzaki, Kaneaki
AU - Tsuchiya, Koichi
PY - 2012
Y1 - 2012
N2 - Most of practical titanium alloys contain some alloying elements such as Nb and Mo, which are prone to segregation. In this study, we have tried to change the distribution of these alloying elements in two types of titanium alloys through thermomechanical treatment. Ti-Al-Nb base inter-metallic alloy, Ti-25Al-14Nb-2Mo-1Fe (mol %), was hot-forged and bar-rolled at 1273K in the (B2+α2) two phase region. After the rolling, Nb and/or Mo-rich region forms swirly band structure. Due to the segregation of these β stabilizing elements, we can obtain heterogeneous distribution of α2 phase particles after the heat treatment at 1273K, Room temperature tensile elongation value was improved from nearly 0 to 6 %, which can be attributed to this heterogeneous distribution of α2 phase particles. We also applied similar thermomechanical treatment on corrosion resistant β-type Ti-12Mo (mass %) alloys, and obtained Mo-rich swirly band-like structures. This led to heterogeneous precipitation of ω phase after aging at temperatures lower than 723K due to the local variation in β phase stability. Room temperature tensile elongation value after aging at 523K for 3. 6ks was improved from 4% to 19% with tensile strength of around 1000MPa.
AB - Most of practical titanium alloys contain some alloying elements such as Nb and Mo, which are prone to segregation. In this study, we have tried to change the distribution of these alloying elements in two types of titanium alloys through thermomechanical treatment. Ti-Al-Nb base inter-metallic alloy, Ti-25Al-14Nb-2Mo-1Fe (mol %), was hot-forged and bar-rolled at 1273K in the (B2+α2) two phase region. After the rolling, Nb and/or Mo-rich region forms swirly band structure. Due to the segregation of these β stabilizing elements, we can obtain heterogeneous distribution of α2 phase particles after the heat treatment at 1273K, Room temperature tensile elongation value was improved from nearly 0 to 6 %, which can be attributed to this heterogeneous distribution of α2 phase particles. We also applied similar thermomechanical treatment on corrosion resistant β-type Ti-12Mo (mass %) alloys, and obtained Mo-rich swirly band-like structures. This led to heterogeneous precipitation of ω phase after aging at temperatures lower than 723K due to the local variation in β phase stability. Room temperature tensile elongation value after aging at 523K for 3. 6ks was improved from 4% to 19% with tensile strength of around 1000MPa.
UR - http://www.scopus.com/inward/record.url?scp=84883066776&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84883066776&partnerID=8YFLogxK
M3 - Conference contribution
AN - SCOPUS:84883066776
SN - 9787030338990
T3 - Ti 2011 - Proceedings of the 12th World Conference on Titanium
SP - 536
EP - 539
BT - Ti 2011 - Proceedings of the 12th World Conference on Titanium
T2 - 12th World Conference on Titanium, Ti 2011
Y2 - 19 June 2011 through 24 June 2011
ER -