Transitory phase transformations during <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.gif" overflow="scroll"><mml:mrow><mml:mo stretchy="true">{</mml:mo><mml:mn>10</mml:mn><mml:mrow><mml:mover accent="true"><mml:mn>1</mml:mn><mml:mo>¯</mml:mo></mml:mover></mml:mrow><mml:mn>2</mml:mn><mml:mo stretchy="true">}</mml:mo></mml:mrow></mml:math> twinning in titanium

Chen, Peng; Wang, Fangxi; Li, Bin

doi:10.1016/j.actamat.2019.04.002

“…Then the BSFs are emitted at the BP interface (Figure 4c), which caused the formation of fcc-Ti in Figure 4d. The formation of fcc-Ti is induced by the accumulation of BSFs, which is consistent with the analysis of Li et al [55]. Figure 4e-h shows the nucleation and growth of 1012 twin at different time steps viewed along the 1210 direction.…”

Section: Twinningsupporting

confidence: 89%

The Plastic Deformation Mechanisms of hcp Single Crystals with Different Orientations: Molecular Dynamics Simulations

Ma

¹

,

Tang

²

,

Mao

³

et al. 2021

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The deformation mechanisms of Mg, Zr, and Ti single crystals with different orientations are systematically studied by using molecular dynamics simulations. The affecting factors for the plasticity of hexagonal close-packed (hcp) metals are investigated. The results show that the basal <a> dislocation, prismatic <a> dislocation, and pyramidal <c + a> dislocation are activated in Mg, Zr, and Ti single crystals. The prior slip system is determined by the combined effect of the Schmid factor and the critical resolved shear stresses (CRSS). Twinning plays a crucial role during plastic deformation since basal and prismatic slips are limited. The 101¯2 twinning is popularly observed in Mg, Zr, and Ti due to its low CRSS. The 101¯1 twin appears in Mg and Ti, but not in Zr because of the high CRSS. The stress-induced hcp-fcc phase transformation occurs in Ti, which is achieved by successive glide of Shockley partial dislocations on basal planes. More types of plastic deformation mechanisms (including the cross-slip, double twins, and hcp-fcc phase transformation) are activated in Ti than in Mg and Zr. Multiple deformation mechanisms coordinate with each other, resulting in the higher strength and good ductility of Ti. The simulation results agree well with the related experimental observation.

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“…Especially, 046201-6 the phase transformation from HCP to FCC lattice has been investigated by numerous researchers. Above these researches, three types of orientation relation (OR) were reported: (I) {0001} HCP ||{111} FCC and ⟨ 1210⟩ HCP ||⟨110⟩ FCC ; [20,22,41] (II) {1010} HCP ||{110} FCC and ⟨0001⟩ HCP ||⟨010⟩ FCC ; [15,16,42,43] (III) {1010} HCP ||{111} FCC and ⟨ 1210⟩ HCP ||⟨110⟩ FCC . [20] For the first OR, the interface between two phases is parallel to the basal plane of HCP matrix {0001} plane, the OR is denoted as B-type OR.…”

Section: Orientation Relation For Allotropic Phase Transformation Of ...mentioning

confidence: 99%

“…There have been numerous researches on the effect of crystal orientation on plastic deformation of HCP materials, and have obtained fruitful theoretical results in recent years. Researches on the plastic behaviors of HCP metallic materials are mainly focused on several common materials such as Mg, [13,14] Ti, [15][16][17][18][19][20][21] and Zr. [22] Ni et al [13] simulated the tensile properties of HCP-Mg nanowire in ⟨1120⟩ orientation and discovered primary and sequential secondary twinning dominated the plastic behavior, which finally resulted in ultrahigh 60% elongation.…”

Section: Introductionmentioning

confidence: 99%

“…Ren et al [18] presented the simulation results that the plasticity of the [11 20]-oriented nanopillars with compressive strain is predominantly produced by the edge dislocation lines. Moreover, Chen [20] reported very interesting transitory phase transformation between BCC, HCP, and FCC structures in HCP-Ti when compression loading is applied along the [10 10] axis.…”

Section: Introductionmentioning

confidence: 99%

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Anisotropic plasticity of nanocrystalline Ti: A molecular dynamics simulation*

An

¹

,

Su

²

,

Deng

³

et al. 2020

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Using molecular dynamics simulations, the plastic deformation behavior of nanocrytalline Ti has been investigated under tension and compression normal to the {0001}, { 1 ¯ 010 } , and { 1 ¯ 2 1 ¯ 0 } planes. The results indicate that the plastic deformation strongly depends on crystal orientation and loading directions. Under tension normal to basal plane, the deformation mechanism is mainly the grain reorientation and the subsequent deformation twinning. Under compression, the transformation of hexagonal-close packed (HCP)-Ti to face-centered cubic (FCC)-Ti dominates the deformation. When loading is normal to the prismatic planes (both { 1 ¯ 010 } and { 1 ¯ 2 1 ¯ 0 } ), the deformation mechanism is primarily the phase transformation among HCP, body-centered cubic (BCC), and FCC structures, regardless of loading mode. The orientation relations (OR) of {0001}HCP║{111}FCC and 〈 1 ¯ 210 〉 HCP | | 〈 110 〉 FCC , and { 10 1 ¯ 0 } HCP | | { 1 1 ¯ 0 } FCC and 〈 0001 〉 HCP | | 〈 010 〉 FCC between the HCP and FCC phases have been observed in the present work. For the transformation of HCP → BCC → HCP, the OR is 0001 α 1 | | { 110 } β | | { 10 1 ¯ 0 } α 2 (HCP phase before the critical strain is defined as α 1-Ti, BCC phase is defined as β-Ti, and the HCP phase after the critical strain is defined as α 2-Ti). Energy evolution during the various loading processes further shows the plastic anisotropy of nanocrystalline Ti is determined by the stacking order of the atoms. The results in the present work will promote the in-depth study of the plastic deformation mechanism of HCP materials.

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“…Other authors also have reported the HCP-Ti to FCC-Ti transformation during the deposition of pure Ti thin films [4], plastic deformation [1, [5][6][7][8][9], and heat treatment process [1, [10][11][12][13]. The stability of FCC-Ti in pure titanium has been proved by molecular dynamics theory [14] Crystals 2021, 11, 1164 2 of 11 and first principles calculation [15,16]. The HCP-Ti to FCC-Ti transition also appears in titanium alloys [17,18] and in Nb-Ti-Si based alloys [19].…”

Section: Introductionmentioning

confidence: 95%

Study on Phase Transformation Orientation Relationship of HCP-FCC during Rolling of High Purity Titanium

Bai

¹

,

Zhu

²

,

Shen

³

et al. 2021

Crystals

8

0

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High purity titanium (Ti) thin strip was prepared by rolling with large deformation and was characterized by the means of Transmission Electron Microscopy (TEM), selected area diffraction (SAED) pattern, high-resolution (HRTEM) analysis, as well as Transmission Kikuchi Diffraction (TKD). It is found that there are face-centered cubic (FCC) Ti laths formed within the matrix of hexagonal close packing (HCP) Ti. This shows that the HCP-FCC phase transition occurred during the rolling, and a specific orientation relationship (OR) between HCP phase and FCC phase obeys ⟨0001⟩α// ⟨001⟩FCC and {100}α//{110}FCC. The ORs of HCP-FCC phase transition are deeply studied by TKD pole figure and phase transformation matrix. It is found that the derived results via pole figure and transformation matrix are equivalent, and are consistent with TEM-SAED analysis results, which proves that these two methods can effectively characterize the ORs of HCP-FCC phase transition and predict possible FCC phase variants.

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Transitory phase transformations during {101¯2} twinning in titanium

Cited by 47 publications

References 69 publications

The Plastic Deformation Mechanisms of hcp Single Crystals with Different Orientations: Molecular Dynamics Simulations

The Plastic Deformation Mechanisms of hcp Single Crystals with Different Orientations: Molecular Dynamics Simulations

Anisotropic plasticity of nanocrystalline Ti: A molecular dynamics simulation*

Study on Phase Transformation Orientation Relationship of HCP-FCC during Rolling of High Purity Titanium

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