Effect of Cutting Crystal Directions on Micro-Defect Evolution of Single Crystal γ-TiAl Alloy with Molecular Dynamics Simulation

Li, Jianhua; Feng, Rui; Qiao, Haiyang; Li, Haiyan; Wang, Maomao; Qi, Yongnian; Lei, Chunli

doi:10.3390/met9121278

Cited by 20 publications

(6 citation statements)

References 28 publications

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“…Consequently, when the stress reaches its peak value, the crack begins to propagate slowly, and the stress decreases gradually. This indicates that Nb enhances the ductility of the TiAl alloy [20]. Two sections with different Nb content were randomly selected for crack analysis, and the crack rate was obtained for each Nb content, as shown in Figure 8(b1,b2).…”

Section: Effect Of Nb On Microstructure Of Jointsmentioning

confidence: 99%

Study on Laser Overlap Welding of Titanium/Aluminum Dissimilar Metals Based on Niobium Microalloying

Pan¹,

Wang²,

Song

et al. 2023

Metals

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Brittle intermetallic compounds, formed during the welding process of titanium/aluminum (Ti/Al), lead to a significant reduction in joint mechanical properties. The purpose of this study is to mitigate the formation of brittle phases during the laser welding of dissimilar Ti/Al metals, thereby enhancing the mechanical properties of the joints. In this investigation, an innovative approach is adopted, utilizing Nb foil as an interlayer to effectively minimize the formation of brittle intermetallic phases during dissimilar welding. A comprehensive analysis of the microstructure of the transition layer was conducted using material characterization methods, including scanning electron microscope equipped with an energy dispersive X-ray spectrometer. The mechanical performance of the welded joints was assessed using tensile testing. The results indicate that the effective welding width and joint penetration depth at the joint interface were reduced in Ti/Al dissimilar metals when Nb was added as an intermediate layer, under the same welding process parameters, when compared to unalloyed weld seams. Furthermore, the utilization of a 0.05 mm Nb foil as the intermediate layer results in a significant 25% increase in the average shear strength compared to the other condition, with the average shear strength of the joint reaching its peak value at 192 N/mm. The unalloyed Ti/Al weld joint usually fractured along the melting zone, displaying complete brittle fracture characteristics. After Nb microalloying, the joint typically fractures along the transition zone and interface, exhibiting both cleavage and ductile fracture characteristics, indicating the combination of a brittle and toughness fracture. This study provides experimental evidence and new insights for welding Ti/Al composite structures, with significant theoretical and practical applications.

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Section: Effect Of Nb On Microstructure Of Jointsmentioning

confidence: 99%

Study on Laser Overlap Welding of Titanium/Aluminum Dissimilar Metals Based on Niobium Microalloying

Pan¹,

Wang²,

Song

et al. 2023

Metals

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“…Face-centered tetragonal (FCT) structure is organized in γ-TiAl. Its lattice structure is depicted in figure 1 [12] , and a TiAl alloy matrix is expanded on the basis of this. Moreover, the slip system and crystal symmetry are diminished by the crystal axis ratio of γ-TiAl, which is c/a=1.02.…”

Section: Simulation Modelmentioning

confidence: 99%

Molecular dynamics simulation of sliding friction behavior of titanium aluminum alloy with vacancy defects

Xing,

wang,

Chen

2023

Ninth International Conference on Mechanical Engineering, Materials, and Automation Technology (MMEAT 2023)

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At the nanoscale, it is still unclear what the mechanical characteristics of a TiAl alloy with vacancy defects are during friction with diamond tips. In this study, a molecular dynamics simulation-based sliding friction mechanism model between a diamond tip and TiAl alloy was created. The wear mechanism at the nano scale was explored in conjunction with friction force, removal atoms, and subsurface damage, and the sliding friction behavior of a TiAl alloy with varying densities of vacancy defects. According to its study, the initial peak of friction strength and the shaking breadth of the aluminum alloy material are reduced when vacancy defects rise. Additionally, it was discovered that when there is a vacancy defect, wear and sliding position adjustments are also in line with Archard's law of wear, and subsurface damage is transmitted from the concentration at the contact point to the front end of the touch point.

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“…where E denotes the cohesion energy; α denotes the elasticity coefficient; r 0 denotes the equilibrium distance between Ti-C and Al-C atoms, and r ij is the distance between atom i and atom j. Table 4 lists the parameter values of E, α, and r 0 in the morse potential function [37,38].…”

Section: Potential Function Selectionmentioning

confidence: 99%

“…The hardness H is calculated from the load-displacement curve, and the hardness indicates the ability of the material to resist local plastic deformation. In this paper, we cited the equation to study nanoindentation in the literature [38]…”

Section: Selection Of the Optimal Processmentioning

confidence: 99%

Atomic simulation of the effect of supersonic fine particle bombardment process parameters on the mechanical properties of polycrystalline γ-TiAl alloy

Cao

Zhou

et al. 2023

Modelling Simul. Mater. Sci. Eng.

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γ-TiAl alloys are the most promising lightweight high-temperature structural materials, but the materials often fail from the surface, which is mainly attributed to the stress state of the material surface. In this paper, the orthogonal experiment method and molecular dynamics modeling are used to choose a set of the best process parameters for supersonic fine particle bombardment. Furthermore, by determining the optimal process parameters, this study examines the influence of residual stress distribution on the mechanical properties of the material under various process conditions. The simulation results reveal that the residual stress distribution is minimally impacted by particle radius, nonetheless, maintaining a moderate level of compressive residual stress within a specific range can substantially augment both the tensile strength and indentation hardness. An increase in the number of particles results in a more uniform distribution of surface residual stresses. Conversely, an increase in the number of impacts causes stress concentration to intensify at the particle's contact point, and thus a deeper distribution of residual stress is observed. This study illustrates how the mechanical properties of polycrystalline γ-TiAl alloy are affected by the process parameters of supersonic fine particle bombardment in terms of atomic size in order to develop and select the optimal supersonic fine particle bombardment parameters.

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Effect of Cutting Crystal Directions on Micro-Defect Evolution of Single Crystal γ-TiAl Alloy with Molecular Dynamics Simulation

Cited by 20 publications

References 28 publications

Study on Laser Overlap Welding of Titanium/Aluminum Dissimilar Metals Based on Niobium Microalloying

Study on Laser Overlap Welding of Titanium/Aluminum Dissimilar Metals Based on Niobium Microalloying

Molecular dynamics simulation of sliding friction behavior of titanium aluminum alloy with vacancy defects

Atomic simulation of the effect of supersonic fine particle bombardment process parameters on the mechanical properties of polycrystalline γ-TiAl alloy

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