Dependence of deformation mechanisms on layer spacing in multilayered Ti/Al composite

An, M.R.; Deng, Qiong; Su, Mengjia; Song, H.Y.; Li, Yu Long

doi:10.1016/j.msea.2016.12.005

“…According to the dislocations analysis, the 𝑐 + 𝑎 dislocations with Burgers vector of 𝑏 = (1/3)⟨ 11 23⟩ have also been activated during the deformation, which glide on { 1101} planes continuously. This OR has been detailedly reported in our previous work, [16,44] and the transformation process is found to be induced by the local stress concentration.…”

Section: (B)supporting

confidence: 73%

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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“…Therefore, the relationship between their mechanical properties and microstructure parameters, and the optimization of these properties, are the hottest topics in this context of recent years [3][4][5][6]. Tremendous efforts have been made to find out the factors influencing the mechanical properties of multilayered films [7][8][9][10][11]. It has been demonstrated that the modulation parameters (such as the modulation period and modulation ratio) and the interfacial structure are the two main factors affecting the mechanical properties of a multilayered film with a particular combination of constituents [12].…”

Section: Introductionmentioning

confidence: 99%

Inapparent Strengthening Effect of Twin Interface in Cu/Pd Multilayered Films with a Large Lattice Mismatch

Weng

¹

,

Chen

²

,

Yue

³

et al. 2019

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It has been found that there are two kinds of interfaces in a Cu/Pd multilayered film, namely, cube-on-cube and twin. However, the effects of the interfacial structure and modulation period on the mechanical properties of a Cu/Pd multilayered film remain unclear. In this work, molecular dynamics simulations of Cu/Pd multilayered film with different interfaces and modulation periods under in-plane tension are performed to investigate the effects of the interfacial structure and modulation period. The interface misfit dislocation net exhibits a periodic triangular distribution, while the residual internal stress can be released through the bending of dislocation lines. With the increase of the modulation period, the maximum stress shows an upward trend, while the flow stress declines. It was found that the maximum stress and flow stress of the sample with a cube-on-cube interface is higher than that of the sample with a twin interface, which is different from the traditional cognition. This unusual phenomenon is mainly attributed to the discontinuity and unevenness of the twin boundaries caused by the extremely severe lattice mismatch.in Cu/Pd multilayered film is unquestionable. Since Cu/Pd multilayered films were first found to have excellent mechanical performance, such as an increase of strength and hardness, in this work, it will be selected as a representative to study the mechanical properties of multilayered films [16][17][18][19][20].The modulation period (λ) and modulation ratio (η) are the thickness of a representative unit in a multilayered film and the ratio of the layer thickness of each constituent, respectively [21,22]. The change of λ and η may induce a change of interface proportion and the space for dislocation movement. Moreover, the grain boundary-dominated deformation mechanism may also vary with the variation of λ and η. For example, as λ decreases, the dominant deformation mechanisms in metallic multilayered films may vary from "dislocation pile-up" to "confined layer slip", or to "interface crossing" [21]. With the decrease of λ, the strengthening caused by the dislocation pile-up is weakened due to fact that a large number of dislocations between the interfaces can be stored in layers. However, the strengthening induced by the glide of single dislocations confined by interfaces ("confined layer slip") or the weakening resulting from dislocation crossing the interface ("interface crossing") dominate would play a leading role. Therefore, λ and η have significant effects on the mechanical properties of a multilayered film. This has an essential guiding significance to establish the relationship between the mechanical performance and modulation parameters for the design and development of high-performance multilayered films with excellent mechanical properties. In this work, we will mainly focus on the effects of λ on mechanical properties.Last but not least, interfaces, the transition zone between two components in nanostructured metallic multilayered films, can act as sources of defects, sin...

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“…The function of the introduced interface to the mechanical properties and deformation behaviors of nanowires was also analyzed. The molecular dynamic study was carried out to study the mechanical behavior of Ti/Cu multilayered nanowires because of the difficulty for the experiment under nano-scale to achieve [9]. The research in this paper will provide guidance for the design and manufacture of multilayered nanowires and contributes to their wide applications.…”

Section: Introductionmentioning

confidence: 99%

Size dependence for mechanical properties of Ti/Cu multilayered nanowire with a semi-coherent interface

Liu

¹

,

Wang

²

,

Su

³

et al. 2023

J. Phys.: Conf. Ser.

0

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Metallic multilayered nanowires have a wide application prospect in micro-nano devices because of their superior physical and chemical properties and microstructure designability. Size effects on the tensile behaviors of Ti/Cu multilayered nanowires are investigated by molecular dynamic simulations. Aspect ratios of 1:4, 1:3, 1:2, 1:1, 1:0.75, and 1:0.67 and sectional dimensions of 3, 4, 5, 6, and 7 nm are adopted to construct nanowires with different sizes. Simulation results indicate that the strength of Ti/Cu nanowires decreases with the decrease of aspect ratio in the large aspect ratio range (>1:2) and all simulated sectional dimension ranges, showing a reverse Hall-Petch effect. The Hall-Petch law can only be satisfied in a small aspect ratio range (<1:2). Deformation mechanism transition is found in the critical aspect ratio of 1:2. When the aspect ratio is larger than 1:2, crystalline phases of Ti and Cu layers dominate the plastic deformation of Ti/Cu nanowires. Crystal phases and interface both bear plastic deformation when the aspect ratio is smaller than 1:2. Interface is an important factor in the strength and deformation of Ti/Cu nanowires. The variation of interface fraction and interaction between interface and dislocation motion determine the tendency of strength variation for Ti/Cu nanowires.

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Dependence of deformation mechanisms on layer spacing in multilayered Ti/Al composite

Cited by 26 publications

References 56 publications

Anisotropic plasticity of nanocrystalline Ti: A molecular dynamics simulation*

Anisotropic plasticity of nanocrystalline Ti: A molecular dynamics simulation*

Inapparent Strengthening Effect of Twin Interface in Cu/Pd Multilayered Films with a Large Lattice Mismatch

Size dependence for mechanical properties of Ti/Cu multilayered nanowire with a semi-coherent interface

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