Effect of thermomechanical treatment on structure and properties of metastable Ti-25Nb-8Sn alloy

Abstract

In this work, different thermomechanical treatment conditions were used to improve the mechanical performances of Ti-25Nb-8Sn. During cold rolling treatment (50, 75, and 90 %), as-cast Ti-25Nb-8Sn underwent a stress-induced phase transformation from a single β phase to a three-phase structure of α + β + ωstr. After the subsequent aging treatment, Ti-25Nb--8Sn presents three-phase β + α + ωiso (at 250 and 400 • C, for 30 min) and two-phase β + α (at 600 • C, for 30 min). At lower aging temperatures (250 and 400 • C), yield strength/modulus (× 1000) ratios of Ti-25Nb-8Sn are dramatically improved with a maximum increase of 143 %, from 9.06 (as-cast) to 16.2-22.0. Under various thermomechanical treatment conditions in this study, the results show that Ti-25Nb-8Sn has excellent yield strength/modulus (× 1000) ratio (∼ 22) and corrosion resistance after 90 % cold rolling and subsequent aging treatment at 250 and 400 • C for 30 min. K e y w o r d s : titanium alloys, biomaterials, cold working, aging, hardness

Biocompatibility of a Ti-Rich Medium-Entropy Alloy with Glioblastoma Astrocytoma Cells

“…Figure 1 a presents the XRD patterns of Ti65M, TNSM, and CP-Ti. Ti65M and TNSM have a single β structure, consistent with previous findings [ 17 , 21 ]. Although the Ti content of Ti65M is lower than 50 wt.%, Ti65M still has a single β structure, as a result of the high-entropy effect.…”

“…Phase identification was carried out with an X-ray diffractometer (XRD) (D8-Advance, Bruker, Germany) using the Cu-Kα radiation at 40 kV, 40 mA, 2θ = 20–90°, scanning speed = 4°/min, and step size = 0.02°/step. A Vickers hardness tester implemented a micro-hardness test (HMV-2T, Shimadzu, Kyoto city, Japan), using a previously described method [ 21 ]. The alloy’s water contact angle measurement was tested using the sessile drop method (1μL deionized water) using the contact angle meter (model 100SL, Sindatek, Taipei city, Taiwan).…”