βTi-Fe 二元合金の累積等時時効による比抵抗, 硬さ, 組織の変化

概要

論文の詳細を見る
After previous result on the solution treated at 1173K for 3.6ks and water quenched (STQ) state, the β phase was retained in alloys containing more than 4mass% Fe. Resistivity of the 5∿15mass% Fe alloys showed the negative temperature dependence. The aging behavior of the quenched Ti-4∿10mass% Fe β alloys with accumulative isochronal aging was investigated by changes in resistivity, hardness, and phase constitution which was identified by X-ray diffractometry. The hardness increases by precipitation of isothermal ω phase and decreases by precipitation of α phase consuming the precipitated ω phase. Above 723K, the hardness of the Ti-4∿6mass% Fe alloys became lower than that of STQ state. In 50K/1.8ks accumulative isochronal aging, the temperature at which precipitation of isothermal ω phase confirmed by X-ray diffractometry increases with increasing Fe content. On the other hand, the influence of Fe content on the temperature of α phase precipitation is not clear. Precipitation of TiFe can not be detected by the X-ray diffraction in accumulative isochronal aging up to 773K. The increase of resistivity of Ti-8mass% Fe and Ti-10mass% Fe alloys at room temperature observed in the aging up to 523K has been attributed to the phase separation in Fe concentration of β phase or the precursor of isothermal ω phase.
社団法人日本鉄鋼協会の論文
1998-03-01