TY - JOUR
T1 - Simultaneous grain refinement and nanoscale spinodal decomposition of β phase in Ti-Nb-Ta-Zr alloy induced by ultrasonic mechanical impacts
AU - Kheradmandfard, Mehdi
AU - Kashani-Bozorg, Seyed Farshid
AU - Kang, Kyeong Hee
AU - Penkov, Oleksiy V.
AU - Zarei Hanzaki, Abbas
AU - Pyoun, Young Shik
AU - Amanov, Auezhan
AU - Kim, Dae Eun
PY - 2018/3/25
Y1 - 2018/3/25
N2 - It was found that ultrasonic nanocrystal surface modification (UNSM) treatment performed on Ti-Nb-Ta-Zr (TNTZ) alloy surface to produce a gradient nanostructured surface layer also resulted in the nano-scale spinodal decomposition of β phase. For the first time, nano-scale spinodal decomposition of β phase induced by ultrasonic mechanical impacts was observed in a short time without any age treatment. The peak shift of XRD to lower angles, (110) β XRD peak splitting, overlapped and asymmetric XRD peaks, satellite reflections in the SAED pattern, and lattice straining in HR-TEM images confirmed nano-scale spinodal decomposition of β phase in the TNTZ alloy induced by UNSM treatment. Nano-scale EDS line-scan probe analysis revealed the β phase separation into nano-scale domains of Ti-rich (β1) and Ti-depleted (β2) phases. HR-TEM images showed the semi-coherent arrangement of Ti-rich (β1) and Ti-depleted (β2) regions. Nanosized grain formation and spinodal decomposition of β phase were induced simultaneously by UNSM treatment. The nano-scale grains, high dislocation density, and semi-coherent interface between the spinodally separated phases contributed to the high hardness of the UNSM-treated TNTZ alloy specimen.
AB - It was found that ultrasonic nanocrystal surface modification (UNSM) treatment performed on Ti-Nb-Ta-Zr (TNTZ) alloy surface to produce a gradient nanostructured surface layer also resulted in the nano-scale spinodal decomposition of β phase. For the first time, nano-scale spinodal decomposition of β phase induced by ultrasonic mechanical impacts was observed in a short time without any age treatment. The peak shift of XRD to lower angles, (110) β XRD peak splitting, overlapped and asymmetric XRD peaks, satellite reflections in the SAED pattern, and lattice straining in HR-TEM images confirmed nano-scale spinodal decomposition of β phase in the TNTZ alloy induced by UNSM treatment. Nano-scale EDS line-scan probe analysis revealed the β phase separation into nano-scale domains of Ti-rich (β1) and Ti-depleted (β2) phases. HR-TEM images showed the semi-coherent arrangement of Ti-rich (β1) and Ti-depleted (β2) regions. Nanosized grain formation and spinodal decomposition of β phase were induced simultaneously by UNSM treatment. The nano-scale grains, high dislocation density, and semi-coherent interface between the spinodally separated phases contributed to the high hardness of the UNSM-treated TNTZ alloy specimen.
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U2 - 10.1016/j.jallcom.2017.12.049
DO - 10.1016/j.jallcom.2017.12.049
M3 - Article
AN - SCOPUS:85039444719
VL - 738
SP - 540
EP - 549
JO - Journal of Alloys and Compounds
JF - Journal of Alloys and Compounds
SN - 0925-8388
ER -