二元系準安定β型チタン合金の二軸圧縮挙動における変形双晶の役割に関する基礎的考察

摘要

Ti-35NbおよびTi-45Nbの単軸圧縮と等二軸圧縮を実施し，変形双晶がもたらす圧縮塑性挙動の特徵と，それに対する変形様式の影響について基礎的な知見を得た.%{332}<113> mechanical twin is known to be activated during plastic deformation of metastable beta-type titanium alloys within a certain range of beta stabilizer content. Although several researchers have been pointed out that the {332}<113> twin contributes to improve the plastic deformation, the activation of the twin under the biaxial stress condition is still unclear. In the present study, the activation of mechanical twinning under uniaxial and equi-biaxial compressions of binary Ti-Nb alloys was investigated. From the obtained results, the difference in the role of mechanical twinning on the plastic deformation under uniaxial and biaxial stress conditions was discussed.