Mechanical behavior of ultrafine-grained/nanocrystalline titanium synthesized by mechanical milling plus consolidation: Experiments, modeling and simulation

Abstract

High quality bulk ultrafine-grained/nanocrystalline titanium samples were prepared through room temperature mechanical milling and conventional consolidation processes. The prepared bulk samples showed high purity, very low porosity and high ductility under compression. The dependency of yield stress and post-yielding behavior on grain size, strain rate and temperature were comprehensively studied. The texture evolution of the ufg/nc samples under compression was measured by synchrotron XRD. On the macroscopic scale, the viscoplastic phenomenological Khan-Liang-Farrokh (KLF) model was used to correlate the experimental results of the ufg/nc Ti.

Creep behavior as dislocation climb over NiAl nanoprecipitates in ferritic alloy: The effects of interface stresses and temperature

“…Creep is time-dependent plastic deformation in the materials under constant load or stress, specifically observed at higher homologous temperature (Khan and Zhang, 2001;Liu et al, 2015). Creep deformation in metal is generally induced by the dislocation generation, motion and annihilation (Basirat et al, 2012).…”

Mechanical Properties of ECAP-Biomedical Titanium Materials: A Review

“…Moreover, the ductility after ECAP was in the 10-20% range, which is sufficient for structural application. The ECAP alone may not result is requisite refine as reported in the latest literature [18]. Jian et al (2015) reported that the strength of ECAPed pure Ti was lower and merely at par with that of Ti-6Al-4V alloy.…”

“…Jian et al (2015) reported that the strength of ECAPed pure Ti was lower and merely at par with that of Ti-6Al-4V alloy. The limited enhancement in strength related to the limited grain size refining capability of the ECAP alone [18]. A large number of investigations are being carried out to further enhance the strength by superposing cold working or SPD processes after the ECAP processing on CP Ti.…”

“…These hybrid processes result in further grain refinement and/or introduce more dislocations which improve the strength. With these strategies strengths above 1 GPa is reported to be obtained, which are typically higher than that of Ti-6Al-4V [18]. Xu et al [19] utilized back pressure equal channel angular pressing (BP-ECAP) to process a Ti-29Nb-13Ta-2Zr β alloy at different temperatures.…”

Mechanical Behavior of Nanostructured and Ultrafine-Grained Metal Alloy under Intensive Dynamic Loading

“…Therefore, constitutive equations taking into account the grain size of metal alloys were offered by Meyers et al [4,18], Armstrong and Zerilli [30], and Khan et al [31,32]. Mishra et al modified the model of Johnson-Cook [33].…”