Effect of High Strain Rate on Adiabatic Shearing of α+β Dual-Phase Ti Alloy

Abstract

In the present work, the localized features of adiabatic shear bands (ASBs) of our recently designed damage tolerance α+β dual-phase Ti alloy are investigated by the integration of electron backscattering diffraction and experimental and theoretical Schmid factor analysis. At the strain rate of 1.8 × 104 s−1 induced by a split Hopkinson pressure bar, the shear stress reaches a maximum of 1951 MPa with the shear strain of 1.27. It is found that the α+β dual-phase colony structures mediate the extensive plastic deformations along α/β phase boundaries, contributing to the formations of ASBs, microvoids, and cracks, and resulting in stable and unstable softening behaviors. Moreover, the dynamic recrystallization yields the dispersion of a great amount of fine α grains along the shearing paths and in the ASBs, promoting the softening and shear localization. On the contrary, low-angle grain boundaries present good resistance to the formation of cracks and the thermal softening, while the non-basal slipping dramatically contributes to the strain hardening, supporting the promising approaches to fabricate the advanced damage tolerance dual-phase Ti alloy.

Effect of High Strain Rates on Adiabatic Shear Bands Evolution and Mechanical Performance of Dual-Phase Ti Alloy

“…In general, ASBs are considered as threshold of mutation damage of metals under dynamic load (Meyers et al, 2001;Walley, 2007). Moreover, ASB will be yielded at the high strain rate attributing to the competition between thermal softening and strain/stress-rate hardening within the local regions (El-Azab, 2008;Rittel et al, 2008;Guo et al, 2019;Hao et al, 2021). Therefore, it is essential to investigate the strain-rate-dependent mechanical properties and structural evolutions of advanced metal materials (Rittel et al, 2008;Guo et al, 2019;Reddy et al, 2020), thus, to reveal the foundations of corresponding plastic deformation behaviours (Hao et al, 2021).…”

“…In order to develop the advanced Ti alloys integrated the damage tolerance and high strength properties, a great amount of efforts have been completed investigating the high-strain rate shear behaviours of α Ti (Shahan and Taheri, 1993;Meyers et al, 1994;Chichili et al, 1998;Yang and Wang, 2006;Wang et al, 2007;Yang et al, 2010;Jiang et al, 2015;Kuang et al, 2017), Ti-6Al-4V alloy (Me-Bar andShechtman, 1983;Grebe et al, 1985;Da Silva and Ramesh, 1997;Lee and Lin, 1998;Timothy and Hutchings, 2013;Sun et al, 2014a;b;Mendoza et al, 2015;Zhou et al, 2017), TC16 (Wang, 2008), near-β Ti5551 (Ran and Chen, 2018) and Ti5553 (Yan and Jin, 2020), β ones (Zhan et al, 2016), α + β dual-phase ones (Yang et al, 2011b;Mantri et al, 2018;Ben Boubaker et al, 2019;Danard et al, 2019;Kloenne et al, 2020;Lee et al, 2020), and so on. It is worth mentioning that the dual-phase materials (Wu et al, 2017;Hao et al, 2021;Zou et al, 2021) always present ultra-strong and ductile behaviors combining the solid solution strengthening, grain refinement effect, and precipitation hardening, which could excellently deal with the planar-defects-dominated plastic deformation behaviors (Hao et al, 2021). In particular, the α + β dule-phase Ti alloys, such as Ti-15Mo-3Nb-2.7Al-0.2Si (wt%) (Mantri et al, 2018), Ti-3Mo-3Cr-2Fe-2Al (Lee et al, 2020, Ti-10V-2Fe-3Al (Danard et al, 2019...…”

“…It is worth mentioning that the dual-phase materials (Wu et al, 2017;Hao et al, 2021;Zou et al, 2021) always present ultra-strong and ductile behaviors combining the solid solution strengthening, grain refinement effect, and precipitation hardening, which could excellently deal with the planar-defects-dominated plastic deformation behaviors (Hao et al, 2021). In particular, the α + β dule-phase Ti alloys, such as Ti-15Mo-3Nb-2.7Al-0.2Si (wt%) (Mantri et al, 2018), Ti-3Mo-3Cr-2Fe-2Al (Lee et al, 2020, Ti-10V-2Fe-3Al (Danard et al, 2019), Ti-0.85Al-4V-0.25Fe-0.25Si-0.15O (Kloenne et al, 2020), Ti-5Al-4Cr-4Mo-2Sn-2Zr (Ben Boubaker et al, 2019), Ti-6Al-2Cr-2Mo-2Nb-2Sn-2Zr (Hao et al, 2021, etc., display an excellent combination of ultimate tensile strength and ductility through optimizing the complex of deformation mechanisms (Hao et al, 2021). At various strain rates or high strain rate, multiple deformation mechanisms including twinning and dislocation can be captured (Hao et al, 2021).…”

“…In particular, the α + β dule-phase Ti alloys, such as Ti-15Mo-3Nb-2.7Al-0.2Si (wt%) (Mantri et al, 2018), Ti-3Mo-3Cr-2Fe-2Al (Lee et al, 2020, Ti-10V-2Fe-3Al (Danard et al, 2019), Ti-0.85Al-4V-0.25Fe-0.25Si-0.15O (Kloenne et al, 2020), Ti-5Al-4Cr-4Mo-2Sn-2Zr (Ben Boubaker et al, 2019), Ti-6Al-2Cr-2Mo-2Nb-2Sn-2Zr (Hao et al, 2021, etc., display an excellent combination of ultimate tensile strength and ductility through optimizing the complex of deformation mechanisms (Hao et al, 2021). At various strain rates or high strain rate, multiple deformation mechanisms including twinning and dislocation can be captured (Hao et al, 2021). It is believed that the adiabatic shear zone is the source of crack initiation and propagation (Wang et al, 2007).…”

“…The traditional wellaccepted thermal-softening mechanism of ASB should be double checked, calling for more research efforts to reveal the microstructure evolutions resulting in the local softening (Guo et al, 2019). Therefore, it is necessary to reveal their corresponding softening mechanisms, including the dynamic recrystallization, dynamic transformation, adiabatic heating, and morphologies texture evolution (Yang and Wang, 2006;Rittel et al, 2008;Osovski et al, 2012;Li et al, 2017;Lieou and Bronkhorst, 2018;Ben Boubaker et al, 2019;Hao et al, 2021).…”