Dislocation Slip Research Articles

Strengthening by {110} and {112} edge dislocations in BCC high entropy alloys

Abstract Mechanical tests and microscopy studies on body-centered cubic (BCC) high entropy alloys reveal transitions from screw to edge dislocation slip and from {110} to {112} slip plane activity. Here, a strengthening theory for BCC edge dislocation slip on {112} planes is thus developed that parallels a recent theory for {110} slip. Using the atomistic dislocation pressure fields for four BCC elements (Nb, Ta, Mo, W) as proxies to span the range of likely alloy cores, theory predicts that the zero temperature yield strength for {112} slip is slightly lower (0%–20%) than that for {110} slip but that the associated energy barrier is slightly (0%–20%) higher. This leads to cancelling effects, and hence very similar strengths, at finite temperatures and strain rates. Full atomistic results on selected dilute binary alloys show some shifts in these trends, but with similar magnitudes and cancelling effects. The close strengths of {110} and {112} slip modes indicate that subtle aspects beyond the scope of the theory will determine which slip system controls the observed strengthening. This closeness in strength cements the use of the {110} edge theory for guiding alloy design independent of actual slip system.

The tensile behaviors of Ag-Cu alloys with different Cu contents: Molecular dynamics simulations study

The Ag-Cu alloys have received attention due to their excellent electrical and mechanical properties. However, the analytical research on why the mechanical properties of the Ag-Cu alloys increase after a small amount of Cu atoms are added is still lacked. In this work, the classical molecular dynamics (MD) simulations method was used to establish the Ag-Cu alloy models with different Cu contents. The tensile deformation mechanism of Ag-Cu alloy at room temperature was revealed from the atomic scale through the analysis of the stress-strain behavior and the evolution of dislocations. During the simulations, the embedded atom method (EAM) potential was used to describe the interaction between Ag atom and Cu atom. The uniaxial tensile deformation and nanostructure evolution of Ag-3 at.% Cu, Ag-6 at.% Cu and Ag-10 at.% Cu alloy models at the temperature of 300 K and the strain rate of 0.02 Å/ps were studied in detail. Results show that the internal stress was generated due to the large lattice mismatch among Ag atom, Cu cluster and the grain boundary. It results in the formation of dislocation and the negative initial stress at the beginning stage of Ag-Cu alloy models under tension. The dislocation firstly nucleates at the grain boundary and the growth rate of dislocation is slow before the crack propagation, and the complex dislocation reactions also exist. With the increase of Cu content, the tensile strengths of Ag-Cu alloys also increase. Cracks mainly form at the intersection of multiple grains, and the fracture mode changes from the intergranular fracture to the intergranular fracture and transgranular fracture after the unstable propagation of cracks. Meanwhile, a plenty of Cu atoms are distributed in the form of clusters in Ag matrix. They hinder the slip of dislocation and slow the relative sliding between atomic layers, and thus finally improves the deformation resistance to the plastic deformation of Ag-Cu alloy. The study on the tensile deformation behavior of Ag-Cu alloy at room temperature has certain guiding significance for the practical production and application of the design of Ag-Cu alloy.

High cycle fatigue properties of Ti-48Al-2Cr-2Nb alloy additively manufactured via twin-wire directed energy deposition-arc

Recently, additive manufacturing for titanium aluminide has received sustained attention. Considering the extensive applications on low pressure turbine blades in aerospace field, dynamic mechanical properties of titanium aluminide, especially the fatigue properties, are of great importance. In present work, fatigue test at ambient temperature was conducted for the first time on twin-wire directed energy deposition-arc (TW-DED-arc) fabricated Ti-48Al-2Cr-2Nb alloy with equiaxed lamellar colonies. More detailed researches on fatigue fracture characteristics and deformation modes are also investigated. The experiment results indicate that TW-DED-arc fabricated Ti-48Al-2Cr-2Nb alloy exhibits flat S–N behavior with a good resistance to fatigue. Fatigue life fluctuates widely at same stress level, but such fluctuations gradually weaken as stress decreases. Furthermore, γ/α2 interface and lamellar colony boundary as well as special microstructures of as-fabricated Ti-48Al-2Cr-2Nb alloy are weak areas during fatigue process, which easily become crack nucleation sites. As stress level decreases, deformation mode of as-fabricated Ti-48Al-2Cr-2Nb alloy translates from twinning and dislocation slip to predominantly dislocation slip. In general, these findings provide an important reference for engineering applications of titanium aluminide.

Achieving an excellent combination of strength and ductility in metastable β titanium alloys via coupling isothermal ω phase and TRIP/TWIP effects

TRIP/TWIP metastable β titanium alloys demonstrate high strain hardening rates and excellent tensile ductility. However, the precipitation of nanometer-sized ω phase through microstructural control significantly improves strength but often results in a significant decrease in ductility. This research proposes a novel strategy by precipitating isothermal ω phase (ωiso) and integrating mechanical twinning/martensitic transformation to address these challenges. The single-phase β coarse-grained (CG) specimens of metastable Ti25Nb (at.%) alloy were subjected to solution treatment in the β phase region, followed by aging at 300 °C for 60 min to obtain CG60. The ωiso-reinforced CG60 specimen exhibited a 12 % uniform elongation (1 % higher than CG specimen) and a yield strength of 857 MPa (approximately 67 % higher than CG specimens). In the CG60 specimen, deformation mechanisms were mainly attributed to the TRIP, TWIP and dislocation slip, with TWIP being predominant. As aging time increased, ω phase (localized barriers) and improved β matrix stability progressively suppressed TRIP and TWIP effects, with TWIP being completely inhibited first. Transmission electron microscopy and computational findings suggest that a denser distribution of ωiso contributes more significantly to the strengthening of the alloy.

Plastic evolution and phase transition mechanisms in γ-TiAl nano polycrystal by a molecular dynamics simulation

γ-TiAl based alloys are widely regarded as one important high-temperature structural material, however the deformation behaviors are still not clearly clarified. The microscopic plastic deformation and phase transition of γ-TiAl nano polycrystals under compression are investigated by molecular dynamics simulations. The results show that the initial plasticity is dominated by slip of partial dislocations whose continuous formation and secondary slip on the same slip plane result in the generation and disappearance of intrinsic stacking faults (ISFs). At the strain of about 0.2, a continuous structure transformation of “ISF → ESF → TB” is observed, during which the interaction between different ISFs causes the atomic misalignment corresponding to the change in atomic stacking order near ISF. As the compressive strain exceeds 0.2, the FCC-to-BCC phase transition occurs within polycrystals due to the high Mises stress, the high stress level within grains facilitates the expansion of BCC phase from initial FCC phase, and the newly formed BCC phase maintains the atomic-arrangement orderliness of original phase. The interface between FCC and BCC phases obeys the low-energy Kurdjumov-Sachs orientation relationship. This work is helpful for better understanding the atomic-scale deformation behaviors and provides a theoretical guidance for designing high-performance alloy materials.

Atomic insights into the ductile–brittle competition of cracks under dissolution

Environmental effects can determine the ductile–brittle behavior of cracks at the atomic scale, but the underlying processes remain poorly understood and contentious. Here, we report the competition between ductile and brittle behaviors at crack tips induced by the prevalent environmental effect of dissolution. Our findings reveal that this competition is driven by two fundamental deformation mechanisms related to dissolution: crack blunting and defect accumulation. Through separate evaluations of dissolution-induced cleavage and dissolution-induced plasticity, we demonstrate that these deformation mechanisms not only dominate brittle fracture toughness but also lead to dislocation slip. We have developed a theoretical model to predict the ductile and brittle behavior of cracks under dissolution, and the theory aligns well with the simulation results and remains consistent with existing experimental trends. This work will broaden the microscopic understanding of ductile and brittle fracture of cracks in complex environments.

Deformation mechanisms of AZ31 Mg alloy sheet assisted by electrical pulse- ultrasonic composite energy field

Ultrasonic vibration and pulsed current can achieve energy concentration and effectively improve the forming ability of Magnesium alloy sheets. The uniaxial tensile tests of AZ31B sheets assisted by electric pulse, ultrasonic and electric pulse-ultrasonic composite energy fields were carried out, respectively. The influence of the effective current density and duration of the electric pulse on the softening, hardening and residual effects in the deformation process caused by the coupling action were explored. The electric pulse suppresses the promoting effect of ultrasonic vibration on twinning and together with ultrasonic vibration promotes dislocation slip to coordinate deformation. The composite energy field can thus further reduce the deformation resistance. The softening, secondary hardening and residual softening phenomena caused by the electric pulse-ultrasonic composite energy field become more and more significant with the prolongation of duration. When the ultrasonic field with a frequency of 21 kHz and an amplitude of 10 μm is combined with a frequency of 600 Hz and the effective current density increases from 0 to 30 A/mm2, the influence on the softening and secondary hardening process exhibits an initial increase followed by a decrease as the current density increases, while the influence on the residual softening shows the opposite trend.

Relative Hardening Contributions and Ductility of As-prepared and Annealed Nanocrystalline Co-P Electrodeposits

The effect of annealing up to 538 °C (1000 °F) on the hardness and ductility of two electrodeposited bulk nanocrystalline cobalt-phosphorus alloys (L-nCoP, 0.14 at%P and H-nCoP, 2.17 at%P) was investigated. Through a combination of electron microscopy and X-ray/synchrotron diffraction characterization, hardness and bend ductility measurements as well as density functional theory calculations, it is shown that hardness is controlled by four additive contributions. At 0.14 at%P, grain size strengthening and likely grain boundary relaxation are the dominant strengthening mechanisms. In the 2.17 at%P alloy, the contributions from solute strengthening and cobalt phosphide precursors and precipitates are much more significant and typical age strengthening behavior is observed with a peak hardness temperature of 371 °C (700 °F). The bend ductility at 0.14 at%P was in the 12 – 17% range up to 482 °C (900 °F). In contrast, the ductility at 2.17 at%P decreased rapidly with increasing annealing temperatures approaching values less than 1% at 427 °C (800 °F) due to excessive cobalt phosphide precursor and precipitate formation. The dominant deformation mechanism in both alloys was found to be basal dislocation slip.

Grain size effect on stress-induced martensite in a metastable β-Ti alloy with ultrahigh strength and strain hardening rate

In the present work, the influence of β grain size on stress-induced martensite (SIM) was investigated in a metastable β-Ti alloy (Ti-4Mo-3Cr-1Fe-1Al). Samples with varying grain sizes were prepared by cold rolling and annealing. The triggering stress for SIM decreases with the grain size increase from 44 μm to 180 μm. Meanwhile, the yield strength increases with decreasing grain size, consistent with the Hall-Petch effect. Fine-grained samples formed a greater number of martensitic bands during deformation compared to coarse-grained samples, resulting in an ultra-high strain-hardening rate ∼4320 MPa. The deformation mechanism of the Ti-4Mo-3Cr-1Fe-1Al alloy consists of the ω to β transformation, SIM, martensite deformation twinning ({110}cc < 1–10>α" and {130}<-310>α" twins), reorientation of martensite and dislocation slip. Both the 44 μm and 59 μm samples exhibit ultra-high true tensile strengths (>1200 MPa), with a large work-hardening interval of nearly 600 MPa relative to the yield strength. This significant work-hardening capability is attributed to interfacial and dislocation strengthening arising from the dynamic formation of martensitic bands during deformation.

Effect of grain size on mechanical characteristics and work-hardening behavior of fine-grained Mg-0.8Mn alloy via adjusting extrusion temperature

In this study, the Mg-0.8Mn (M08, wt%) alloy is subjected to hot extrusion at various temperatures ranging from 150 ℃ to 300 ℃, and the correlations between the microstructure evolution, tensile properties, and work hardening behavior at ambient temperature are elaborated. The M08 alloy extruded at 150 ℃ exhibits a bimodal microstructure, which included undynamic recrystallized (unDRXed) grains and fine dynamic recrystallized (DRXed) grains with an average size of 1.4 μm. As the extrusion temperature exceeds 210 °C, fully DRXed grains can be observed with grains growth becoming more pronounced with the increase of extrusion temperature. Notably, Mn atomic segregations are evident at the grain boundaries (GBs) in the M08 alloy extruded at 150 °C. It is also essential to highlight that the propensity for GB segregation is diminished with higher extrusion temperature, and the amount of α-Mn precipitates within grain interiors is increased in the M08 sample extruded at 300 ℃. An intriguing observation is the abnormal rise in yield strength (YS) with grain size as the extrusion temperature is increased. This phenomenon can be attributed to the diminishing effect of GB sliding and the concurrent enhancement of GB strengthening effect. However, as the extrusion temperature is raised from 150 °C to 300 °C, the ductility of M08 alloy experiences a substantial decline from 74 % ± 4–16 % ± 3 %. Meanwhile, the grain growth can bring about an increased strain hardening rate, which is primarily dependent on the transition in the dominant deformation mechanism from grain boundary sliding (GBS) to dislocation slip. This transition leads to a more substantial accumulation of dislocations within the coarser grains, thereby affecting the mechanical behavior of M08 alloy. This work provides valuable insights into the influence of extrusion temperature on the microstructure evolution and mechanical properties of Mg-0.8Mn alloy, offering a foundation for optimizing the processing parameters to achieve desired mechanical performance.

Microstructure and dynamic deformation mechanism of laser powder bed fusion of 316L-containing Ti–6Al–4V with dual-phase heterostructure

In this paper, 316L-containing Ti–6Al–4V alloy was fabricated by laser powder bed fusion (LPBF) through mixing Ti–6Al–4V and 4.5 wt% 316L powders, and the dynamic compressive mechanical properties and deformation mechanism at different strain rates were studied. The results show that the volume fraction of β phase sharply increases from 1.8% (in TC4) to 61.4% (in HST), and micro- and submicron-sized grains coexist in the HST alloy, producing heterostructure in the form of bimodal grain size distribution. The presence of the heterostructure led to superior heterogeneous deformation induced stress, thus facilitating the additional strain hardening and deformation coordinating ability, thus made the HST alloy achieved ultimate compressive stress of ∼1750 MPa and fracture strain of ∼17%, showing excellent comprehensive mechanical properties. Under quasi-static load, the deformation mode of HST alloy is mainly attributed to progressive deformation-induced martensitic transformation. However, at high strain rates, the impact loading inhibited the activation of progressive DIMT, and thus the deformation mode changed to combination of dislocation slipping and deformation twinning.

Influence of phase composition and stress on the corrosion behavior of metastable β titanium alloy Ti-5Mo-5V-6Cr-3Al in 15 wt% HCl solution

Immersion experiments, electrochemical tests under different tensile stresses, and microstructure observation using SEM, EBSD, and TEM were carried out on three Ti-5Mo-5V-6Cr-3Al alloys with different phase compositions in 15 wt% HCl solution to clarify the effects of the phase compositions and stresses on the corrosion behavior of metastable β-titanium alloys in acidic media. The microstructure with only primary α-phase on the β-matrix (No. M1) presents the smallest corrosion current density and the highest corrosion potential, indicating relatively the best corrosion resistance; the microstructure with both primary and secondary α-phase on the β matrix (No. M2) has moderate corrosion resistance; and the microstructure with secondary α-phase precipitated on the β matrix (No. M3) has the relatively poorest corrosion resistance. The results of the immersion experiments show the same regularity as the electrochemical tests. The corrosion resistance of all three microstructures decreases as the degree of stress loading increases. The apparently small amount of α-phase content in M1 is the reason for the difference in corrosion resistance between M2 and M3, M3 alloys with larger average grain sizes exhibit better corrosion resistance than M2 alloys. Under tensile loading, disruption of the surface passivation film and pitting promoted by dislocation slip are the main reasons for the reduction in the corrosion resistance of the alloy.

The microstructure evolution and mechanical properties of Ti–1300 alloy during ECAP deformation and subsequent aging treatment

The effect of Equal channel angular pressing (ECAP) deformation on the microstructure, mechanical properties, and aging behavior of solution treated Ti–1300 alloy was investigated. The results show that the grains are not broken during ECAP deformation due to coordination of grain rotation. The dominant deformation mechanism involved dislocation slip and twinning. The ECAP deformation has a significant effect on the subsequent aging behavior. The microstructure of aged samples comprised αs phase in β matrix. The precipitation of αs phase in the pre-deformed sample is higher than that in the solution treated sample, which is reflected in the improvement of microhardness of the pre-deformed + aging sample. The microhardness of the alloy after ECAP deformation increases with decreasing aging temperature and increasing aging time.

Molecular dynamics study on mechanical properties and plastic deformation mechanism of GNPs/Mg composites

This study utilizes molecular dynamics methods to embedded GNPs (graphene nanosheets) of uniform size and thickness into single crystal Mg, establishing a GNPs/Mg composite model. The mechanical properties and plastic deformation behavior of the composite under various compression conditions (volume fraction of GNPs, strain rate, and temperature) are investigated. The results indicate that uniformly distributed GNPs enhance load transfer and provide dispersion strengthening, effectively improving the composite's mechanical properties. As the volume fraction of GNPs increases, the yield stress of the composite first increases and then decreases. When the volume fraction of GNPs is 3.9%, both the yield stress and Young's modulus of the composite reach their maximum values of 9.16GPa and 108.83GPa, respectively. The uniformly dispersed GNPs constrain dislocations on prismatic and pyramidal planes, thereby suppressing twinning deformation. Consequently, dislocation slip predominantly occurs as 1/3<-1100> partial dislocations on the (0001) basal plane. Young's modulus is not sensitive to strain rate; as the strain rate increases from 0.0025Å·ps⁻¹ to 0.0125Å·ps⁻¹, the yield stress rises from 8.50GPa to 10.42GPa. At high strain rates, only some dislocation sources are activated, and the number of 1/3<-1100> partial dislocations decreases with increasing strain rate. Within the temperature range of 100K to 500K, both the elastic modulus and yield stress of the GNPs/Mg composite decrease with increasing temperature.

Deformation behavior of Gd alloyed CoCrFeNi high entropy alloy at high temperature under the influence of local nano-ordered structure and misorientation

The thermomechanical processing (TMP), which is an industrial process that includes deformation and heat treatment, represents a novel approach to enhancing the mechanical properties of metallic materials. However, it requires extensive research on the high-temperature deformation behavior of alloys during its application process. The present study conducts hot compression tests at 700 °C and 800 °C, as well as detailed microstructural characterization of the deformed material after hot deformation, to comprehensively discuss the mechanical properties and deformation behavior at high temperature of the (CoCrFeNi)100-xGdx (x = 0, 0.5, 1, 2, 3 at.%) HEAs. The (CoCrFeNi)100-xGdx HEAs exhibit an excellent combination of strength and plasticity in high temperature. The original dendritic microstructure in the (CoCrFeNi)100-xGdx HEAs was completely fractured and transformed into a mass of deformed structures during thermal deformation. The mechanical properties at high temperature of the alloy system originate from the misorientation in the microstructure. Dislocation slip is the main deformation mechanism of the alloy system at high temperature. The coordinated deformation of the soft orientation for FCC phase and the hard orientation for HS phase affects the dislocation morphology in the microstructure. Dynamic recovery (DRV) plays a dominant role in the flow behavior of the alloy at high temperature, and work hardening is the main strengthening mechanism during plastic deformation. The correlation between microstructure evolution and mechanical properties of Gd alloyed CoCrFeNi HEAs during hot deformation has been established through comprehensive studies on deformation behavior.

Van der Waals semiconductor InSe plastifies by martensitic transformation.

Inorganic semiconductor materials are crucial for modern technologies, but their brittleness and limited processability hinder the development of flexible, wearable, and miniaturized electronics. The recent discovery of room-temperature plasticity in some inorganic semiconductors offers a promising solution, but the deformation mechanisms remain controversial. Here, we investigate the deformation of indium selenide, a two-dimensional van der Waals semiconductor with substantial plasticity. By developing a machine-learned deep potential, we perform atomistic simulations that capture the deformation features of hexagonal indium selenide upon out-of-plane compression. Unexpectedly, we find that indium selenide plastifies through a martensitic transformation; that is, the layered hexagonal structure is converted to a tetragonal lattice with specific orientation relationship. This observation is corroborated by high-resolution experimental observations and theory. It suggests a change of paradigm, where the design of new plastically deformable inorganic semiconductors can focus on compositions and structures that facilitate phase transformations, going beyond the conventional dislocation slip.

Precipitation Refinement via Aging Time Modification for Enhancing Wear Resistance in Ti–V–Nb Microalloyed High‐Manganese Steels

It is imperative to ensure an even distribution of refined precipitates to enhance wear resistance. Herein, different heat treatments are to control the size and distribution of precipitates. The treatments include water quenching at 1100 °C followed by aging at 400 °C for 24, 60, and 84 h, designated as AT24, AT60, and AT84, respectively. The microstructure, mechanical properties, and impact wear properties of high‐manganese steel are investigated under solution and aging conditions using scanning electron microscopy, field‐emission scanning electron microscopy, tensile testing, and impact abrasive wear testing. Notably, the absence of nanoscale precipitates largely accounts for the poor wear resistance of as‐casting steel, whereas the strengthening effect of larger micrometer‐sized precipitates is insufficient. After the solution and aging treatment, nanosized precipitates continuously form within the matrix, conducive to the formation of the deeper work‐hardening layer, thereby improving the wear resistance. The fine micrometer‐sized precipitates and evenly distributed nanoscale precipitates in AT60 actively contribute to toughness. Additionally, these precipitates interact with slip dislocations, providing stronger strengthening via the Orowan looping mechanism. The wear mechanisms of steel can be transformed from wide, deep pits to shallow grooves and microcutting by extending the aging time.

Effects of Ca contents on microstructures and mechanical properties of friction stir processed Mg alloys

Ca alloying is beneficial for improving the uniform elongation for friction stir processed (FSPed) Mg-4Al-2Sn-xCa (0, 0.5, 1.0 and 1.5 wt.%) (AT42-xCa) alloys. Coarse CaMgSn and Al2Ca particles in as-cast AT42-xCa alloys lead to a sharp decrease in elongation. Friction stir processing (FSP) is effective in improving strength and elongation by refining grain structure along with CaMgSn and Al2Ca particles, and inducing grain orientations with high Schmid factors for basal slip. Consequently, FSPed AT42-0.5Ca alloy exhibits simultaneously enhanced ultimate tensile strength (∼224 MPa) and elongation (∼30.9%). Compared to the Ca-free alloy, 0.5 wt.% Ca alloying increases the heat input and promotes the dislocation recovery, reducing residual dislocations. Nano-sized CaMgSn precipitates in grain interiors inhibit the dynamic recovery of dislocations during tensile, facilitating the work-hardening ability. Besides, high Schmid factors facilitate basal dislocation slips. Therefore, high EL is primarily due to the dislocation-free fine grain (∼2.7 μm), refined CaMgSn particles (micron-sized particles (∼1.3 μm) and nano-sized precipitates (∼55 nm)) and high Schmid factors (∼0.446) for basal slips.

Plastic deformation of [001]-oriented single-crystal iron under shock compression: Effects of void size

The thermomechanical behavior of materials is known to be sensitive to preexisting defects in their microstructure. In this paper, non-equilibrium molecular dynamics simulations have been used to investigate the effects of the microvoid size on the plastic deformation in single-crystal iron shock-compressed along the [001] crystallographic direction. The higher the microvoid radius, the faster the kinetics of dislocations. Thus, as the microvoid radius increases, the plastic activity evolves from a regime where the deformation is dominated by twin activities to a regime where both twin and dislocation activities play an essential role and then to a regime where the deformation is dominated by dislocation slip. Furthermore, in both defect-free and defective initial crystal states, the elastic precursor wave is observed to decay with propagation distance, resulting in a constitutive functional dependence of the yielding pressure, σE, on the plastic deformation rate, ε˙p. In the regime where both deformation twinning and dislocation slip play important roles, the constitutive behavior is consistent with the original Swegle–Grady model and is in overall agreement with experimental data and thermomechanical simulations.

Study on micro-deformation in micro-grinding of selective laser melting FeCoCrNi high-entropy alloy based on molecular dynamics

Microscopic deformation behavior is an important part of the study of micro-grinding processing. This paper investigates the removal mechanism in the micro-grinding of selective laser melting FeCoCrNiAl0.5 high-entropy alloy. The micro-grinding process is analyzed through simulation using the molecular dynamics simulation method. The study examines how the thickness of the undeformed chip and the grain size affect the microdeformation behaviors of shear strain, micro-grinding force, the evolution of dislocations, and microstructural transformation. The experimental results confirm that the molecular dynamics simulation model accurately predicts the micro-deformation behavior of FeCoCrNiAl0.5 high-entropy alloy during micro-grinding. The micro-deformation mechanism involves dislocation slip and twinning deformation, while the removal mechanism mainly includes the elimination of axial and dendritic crystals. During micro-grinding, the grinding force experiences small to large fluctuations, and the total length of dislocations gradually increases. As the undeformed cutting thickness increases, the micro-grinding force also gradually increases. Simultaneously, the type of dislocations and laminar dislocation nuclei increase, leading to growth in the total length of dislocations. The number of high shear strain atoms, the micro-grinding force, and the degree of fluctuation in the single crystal high-entropy alloy are higher than those in the polycrystalline material, but the total dislocation length is significantly smaller.