Initial β Grain Size Effect on High-Temperature Flow Behavior of Tb8 Titanium Alloys in Single β Phase Field

Abstract

The high-temperature flow behavior of TB8 titanium alloys with two different grain sizes was investigated in this present work. Results show that a significant characteristic of stress drop is visible at the start stage of the hot deformation process when the strain rates are 100 and 10−1 s−1. With the further increasing of strain, the flow stress initially rises to a maximum value and subsequently attains a plateau for the strain rates of 100 s−1 and a slight decrease for the strain rates of 10−1 s−1. Only dynamic recovery occurs under these deformation conditions. When the strain rates drop to 10−3 s−1, the dynamic recrystallization takes place during hot deformation. The values of deformation activation energy and materials constants at different strains were calculated. The processing maps at different strains were established for the fine- and coarse-grained alloys. The optimal processing parameter for hot processing was attained to be 900 °C/10−3 s−1 for fine-grained alloys and 950 °C/10−3 s−1 for coarse-grained alloys, respectively.

High Temperature Deformation Behavior of Near-β Titanium Alloy Ti-3Al-6Cr-5V-5Mo at α + β and β Phase Fields

“…Meanwhile, different near-β titanium alloys exhibit distinct instability and suitable deformation regions, other flow stress behaviors, and DRV and DRX behaviors. The works reported by the literature [19][20][21][22][23] also performed similar research and confirm this phenomenon.…”

A comprehensive review on the deformation behavior of refractory high entropy alloys at elevated temperatures

“…According to Prasad et al [101], the unsafe deformation behavior include: flow localisation, void formation, inter-crystalline cracking, wedge cracking, kink bands and adiabatic shear bands. Unsafe deformation behavior have been reported in metallic alloys: IN738LC (deformation bands and grain boundary cracking) [102]; Ni3Al (flow localization, adiabatic shear bands and cracks) [74]; Ti 15 Mo 3 Al 3 Nb 0.2 Si (cracks) [60] and TB8 titanium alloy (flow localization and shear bands) [61]. The unsafe deformation behavior have also been reported in RHEAs.…”

“…At 1100 °C and strain rates of 10 À3 s À1 , the flow curves of IN718 alloy revealed a dynamic recrystallization mechanism. When the strain rates decrease to 10 À3 s À1 , the dynamic recrystallization occur during the hot deformation of TB8 titanium alloy [61]. The flow stress of hot deformed C276 superalloy increases sharply with strain until a peak flow stress because of WH at the start of deformation, and then the flow stress reduces gradually with the strain because of dynamic recrystallization.…”

Titanium Alloys: Processing and Properties

“…Looking to the future, the FAST process offers greater sustainability and more efficient use of titanium resources given that machining revert material can be employed as an alternative source stock [16]. Flow stress characterisation by Yang et al [17], again employs compression testing but this time employing a more traditional wrought product, albeit a novel metastable β alloy, as the vehicle of interest. Yan et al [18] then consider the sensitivity of a near α sheet product to grain size and pre-forming annealing heat treatments with an eye to super plastic forming capability.…”