A general study of commercially pure Ti subjected to severe plastic deformation: microstructure, strength and corrosion resistance

Filho, Anibal de Andrade Mendes; Rovere, Carlos Alberto Della; Kuri, S.E.; Sordi, Vitor Luiz; Ferrante, M.

doi:10.1590/s1517-70762010000200024

Cited by 11 publications

(4 citation statements)

References 8 publications

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“…Indeed, several works investigating the microstructure of ECAPed UFG Ti report sub micrometer grain sizes and high dislocation densities. [27,30,31,33,34,36,37,40,41] An estimated density of 10 14 m À2 was calculated by Valiev et al [30] A nonuniform distribution of dislocations that tend to accumulate and tangle around grain boundaries was also observed in ECAPed UFG Ti. [35,39,62] This was confirmed in the current investigation, as shown by the TEM image in Figure 4.…”

Section: Non-uniform Distribution Of Dislocations In Ufg Timentioning

confidence: 99%

“…[13,18,22] In recent years, investigations on the mechanical behavior of ultrafine-grained titanium (UFG Ti) processed by severe plastic deformation (SPD) have received considerable attention due to its potential applications, primarily in the biomedical field. However, these studies have either ignored [27][28][29][30][31][32][33][34][35][36][37][38][39][40][41] or merely superficially discussed [42][43][44] the possible occurrence of DSA. Serrations in stress-strain curves were never analyzed in the UFG Ti processed by equal channel angular pressing (ECAP) [27,28,[31][32][33]35,36,[38][39][40][41] or equal channel angular extrusion (ECAE), [34,37] even though they were observed.…”

Section: Introductionmentioning

confidence: 99%

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Room Temperature Dynamic Strain Aging in Ultrafine-Grained Titanium

Lopes

Zhao

et al. 2015

Metall Mater Trans A

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Dynamic strain aging (DSA) in coarse-grained (CG) titanium is usually observed at intermediate to high temperatures 473 K to 973 K (200°C to 700°C) and is characterized by serrations in the stress vs strain curves. In the present work, despite the absence of apparent serrations, ultrafine-grained titanium (UFG Ti) undergoes DSA at room temperature, exhibited through an abnormal increase in the elastic limit and negative strain rate sensitivity. This effect is observed at 293 K (20°C) in the strain rate interval of 10 À4 to 10 À2 s À1 , and at 203 K (À70°C) and 373 K (100°C) in a distinct strain rate range. Based on a calculated activation energy of 17.3 kJ/mol and microstructural observations by transmission electron microscopy, it is proposed that the dominant mechanism for DSA in UFG Ti involves interstitial solutes interacting with dislocations emitted from grain boundaries. The interstitials migrate from the grain boundaries along dislocation lines bowing out as they are emitted from the boundaries, a mechanism with a low calculated activation energy which is comparable with the experimental measurements. The dislocation velocities and interstitial diffusion along the dislocation cores are consistent.

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Section: Non-uniform Distribution Of Dislocations In Ufg Timentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Room Temperature Dynamic Strain Aging in Ultrafine-Grained Titanium

Lopes

Zhao

et al. 2015

Metall Mater Trans A

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“…According to the classic corrosion theory, the increased density of grain boundary and triple junction in nanostructures would have a detrimental effect on the overall electrochemical corrosion performance of NC metals. However, previous investigations on the electrochemical corrosion behavior of NC and ultrafine-grained (UFG) materials have shown many interesting results (Kim and Kim, 2013; Hajizadeh et al , 2015; Imantalab et al , 2016; Mendes Filho et al , 2010; Maleki et al , 2014). Some research demonstrated the electrochemical corrosion resistance of the metals was improved, such as NC Ni in 10Wt.% NaOH (Wang et al , 2006), NC FeAl alloy in 0.5 M H 2 SO 4 solution (Kedim et al , 2004), NC Zn-Ni alloy coating in 3Wt.% NaCl solution (Mosavat et al , 2012) and UFG Cu in 0.5 M HCl (Deng et al , 2013).…”

Section: Introductionmentioning

confidence: 99%

Electrochemical corrosion behavior and surface passivation of bulk nanocrystalline copper in alkaline solution

Luo

Xv³

et al. 2020

ACMM

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Purpose This paper aims to focus on an assessment of the electrochemical corrosion performance of bulk NC copper in a variety of corrosion environments. Design/methodology/approach The electrochemical corrosion behavior of bulk nanocrystalline (NC) copper prepared by inert gas condensation and in situ warm compress technique was studied by using potentiodynamic polarization and electrochemical impedance spectroscopy tests in de-aerated 0.1 M NaOH solution. Findings NC copper exhibited a typical active-passive-transpassive behavior with the formation of duplex passive films, which was qualitatively similar to coarse-grain (CG) copper. Although a compact passive film formed on NC copper surface, the corrosion resistance of NC copper was lower in comparison with CG copper. The increase in corrosion rate for NC copper was mainly attributed to the high activity of surface atoms and intergranular atoms. These atoms led to an enhancement of passive ability and an increase of dissolution rate of passive film in oxygen-deficiency solution. For NC copper, the corrosion resistance decreased as grain size increased in NC range. Originality/value The difference in corrosion resistance between bulk NC copper and its CG counterpart is dependent upon the corrosion solution. In a previous work, the potentiodynamic polarization tests revealed that NC copper bulks (grain size 48, 68, 92 nm) had identical corrosion resistance to CG copper bulk in naturally aerated 0.1 M NaOH solution. The results might be related to the dissolved oxygen in the medium.

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“…Other works have been reported in the literature on a series combination of ECAP process with other SPD methods to enhance better biomedical titanium material properties. Mendes et al [49] studied microstructure and strength of CP-Ti grade2 under combined processes of warm ECAP at 4 passes, 300 o C then cold rolling (CR) at 70% reduction thickness. Results showed an increase of; tensile strength (from 408-796MPa), hardness (from 140-271HV) compared to annealed condition.…”

Section: Performance and Prospects Of Severe Plastic Deformation For mentioning

confidence: 99%

Performance and Prospects of Severe Plastic Deformation for Effective Biomedical Titanium Alloys

2018

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A B S T R A C TApplication of severe plastic deformation (SPD) technology to process effective biomedical titanium alloys has shown promising results at laboratory scale. However, more research is still required before adopting this technology from laboratory scale to industrial scale production. This review presents performance and prospects of SPD for effective ultra-fine/nanograin structure-biomedical titanium alloys. Effective biomedical titanium alloys should have desired properties for the medical application. The properties include; high static and fatigue strengths, surface hardness for wear resistance, good ductility, corrosion resistance and biocompatibility. Based on current works reported in the literature, the review focused on; high-pressure torsion (HPT), equal channel angular pressing (ECAP), asymmetric rolling (AR), accumulative roll bonding (ARB) and repetitive corrugation and straightening (RCS). Overview of biomedical application of titanium alloys and desired material properties is presented. A detail discussion on the working principle, performance (e.g. induced strength, hardness, grain size and texture etc.) and material deformation homogeneity of each SPD method are presented. Also, prospects and challenges of each SPD method to be implemented at industrial scale for continuous and mass production are highlighted. The review concludes with the effectiveness of SPD processes, characteristics of processed samples and suggestion of future work for SPD to process effective biomedical titanium alloys at industrial scale.

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A general study of commercially pure Ti subjected to severe plastic deformation: microstructure, strength and corrosion resistance

Cited by 11 publications

References 8 publications

Room Temperature Dynamic Strain Aging in Ultrafine-Grained Titanium

Room Temperature Dynamic Strain Aging in Ultrafine-Grained Titanium

Electrochemical corrosion behavior and surface passivation of bulk nanocrystalline copper in alkaline solution

Performance and Prospects of Severe Plastic Deformation for Effective Biomedical Titanium Alloys

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