Compressive Stress State Research Articles

Influence of External Plane Stress on Electric Parameters of AlGaN/GaN HEMT Heterostructures

Herein, the influence of stresses on parameters of 2D electron gas (2DEG) in AlGaN/GaN high‐electron‐mobility transistor‐type heterostructures grown on sapphire substrate by metal–organic vapor‐phase epitaxy technique is presented. The as‐grown heterostructures as well as Schottky diodes fabricated in them are subjected to compressive stress. The custom stressing system induces a homogeneous state of compressive stress in the samples without causing electrical side effects. Time‐dependent heterostructures characteristics of electron concentration, electron mobility, and bandgap width are measured. Additionally, in the case of the Schottky diodes, current–voltage characteristics and charge flow in the contact are measured. The measurements are performed in cycles with and without applied stresses to determine the repeatability of effects and to separate the influence of thermal and electrical factors. Additionally, electrical simulations are performed using APSYS software package. The obtained results lead to conclusions that are different to those reported in existing literature, especially in regard to the time dependence of the measured effects, that is essential to proper explanation. It is also shown that a key role in the change of 2DEG parameters is played by deep surface states and interlayer piezoelectric effects. Finally, the anisotropic character of the derived relations is demonstrated.

Pseudo-anisotropic damage model of randomly oriented strands (ROS) for reproducing flexural damage behavior

We developed a pseudo-anisotropic damage model of randomly oriented strands (ROS) reinforced thermoplastic composites for reproducing flexural deformation and damage behavior by finite element analysis (FEA). The damage model applied stress triaxiality to capture the differences in the damage initiations among the tensile, compressive, and shear stress states. The damage model also included equivalent damage propagation function depending on the interlaminar shear property of ROS. The developed FE model was focused on the characteristics that ROS composites show macroscopic in-plane isotropic and out-of-plane anisotropic mechanical properties because of the laminated structure of ROS. Furthermore, all of the material parameters in the FE model were identified by performing simple deformation tests. As a result, the flexural numerical simulation could reproduce the experimental flexural deformation and damage behaviors of ROS plates with different thickness despite a complex stress state including in-plane and out-of-plane stresses. The developed FE model has potential to evaluate the safety of ROS-manufactured structural components. The evaluation of safety by FEA constructed in this study can improve the applicability of ROS composites.

TRISO Burnup-Dependent Failure Analysis of a HTGR Design-Basis Accident Using BISON

This work assesses the failure behavior of the silicon carbide (SiC) layer in TRIstructural ISOtropic (TRISO) fuel particles with BISON during both steady-state and transient conditions for the MHTGR-350 design by General Atomics. A one-dimensional BISON model for a uranium oxycarbide–bearing TRISO is developed to simulate a power level of 50 mW/particles up to 12.4% fissions per initial metal atom (FIMA). Stress predictions for the materials of interest are presented as a function of burnup, along with the SiC failure probability computed using Weibull statistics under the assumption of realistic SiC quality. A design-basis accident (DBA) that involves control rod withdrawal is then simulated in BISON at various burnup levels. Boundary conditions during the DBA are obtained from RELAP5-3D. The predicted SiC failure probability is 3 × 10−14%. This value does not increase during the transient as a function of burnup since irradiation induces a compressive hoop stress state that reaches a maximum absolute value of around 300 MPa. This compressive stress compensates the tensile loading conditions introduced by the transient. The tensile components appear amplified at higher burnups since they increase from 100 to 140 MPa going from 6% FIMA to 12.4% FIMA. Nonetheless, burnup provides a negligible impact on the overall failure probability predictions for SiC, as transient conditions do not translate to a stress increase toward tensile values at any of the considered burnups. Additionally, a two-dimensional (2-D) exploratory BISON model is developed to determine the effects of inner pyrolytic carbon (IPyC) crack formation on SiC. IPyC failure is predicted using Weibull statistics at 105 days from the beginning of irradiation, which is set as the time for crack initiation using XFEM in the 2-D BISON model. Stress concentrations induced by the crack cause the SiC failure probability to increase with respect to the intact particle case by approximately 10 orders of magnitude. Maximum stress concentrations are found at the time of crack formation, after which stress relaxation is observed during remaining steady-state irradiations and subsequent transient simulations. Considerations are made on the results of the 2-D model being contingent on both mechanical and anisotropy properties for pyrolytic carbon. Recommendations are provided for future work involving higher dimensionality models, further investigations on uncertainties, material properties, and additional designs, such as the fluoride salt-cooled high-temperature reactor, that operate at higher burnups.

High energy laser shock peening of Ti6Al4V alloy without any protective coating

Industrial laser shock peening (LSP) is gradually moving away from using protective overlay as it is tedious and time-consuming making the whole process inefficient for a production run. However, the peening of titanium alloys is still performed with the protective coating to protect the surface from thermal exposure to the laser. In this work, we study the effect of uncoated LSP (without protective coating) of Ti6Al4V alloy on its surface microstructure and mechanical performance. Our results show that uncoated LSP produces a thin oxide layer consisting of TiO2 and Al2O3 due to oxygen diffusion facilitated by the thermal effect of the laser. A brittle alpha layer around 5–8 µm thick is also generated on the surface. We find that similar compressive residual stress conditions as that in coated LSP can be generated beneath the surface by increasing peak power density in uncoated LSP. Despite this, the fatigue performance of the peened alloy does not improve, which is attributed to the presence of several microcracks in the alpha layer. On the other hand, the removal of the alpha layer by abrasive grinding is found to increase the fatigue life by almost 9 times compared to that from uncoated LSP. The findings indicate that the uncoated LSP of Ti6Al4V alloy must be combined with a post-cleaning step to reap the significant improvement in fatigue life.

TRISO burnup-dependent failure analysis in FHRs using BISON

In this study, we perform a study on TRIstructural ISOtropic (TRISO) Silicon Carbide (SiC) layer failure using the BISON fuel performance code. SiC thermomechanical behavior is analyzed during both steady-state and accident scenarios pertaining to a Fluoride-Salt-Cooled High-Temperature Reactor (FHR). A monodimensional single particle model is adapted from a previous analysis and run at 140 mW/particle for 500 days. The maximum burnup reached is 18.49% FIMA. A total of three accident scenarios are simulated at both fresh fuel conditions and following multiple irradiations at 2% FIMA increments up to 18.49% FIMA. The instances include an overcooling transient, a Control Rod Withdrawal (CRW) and a Loss of Forced Cooling Accident (LOFA). SiC hoop stress and failure probability predictions are evaluated for all simulated cases. A consistent tangential compressive stress state is found as a function of burnup for SiC. The maximum compressive hoop stress reaches approximately -400 MPa. The maximum SiC failure probability as a function of burnup is 2⋅10−13% at steady-state and no increases are predicted during transient simulations. It is concluded that the selected accident scenarios, under our modeling assumptions, are not predicted to pose a challenge to SiC integrity due to their relatively slow progression and low temperature increments, for both fresh fuel and at burnup values up to 18.49% FIMA. A 2D model is used, along with XFEM, to simulate a crack in the Inner Pyrolytic Carbon (IPyC). Conservative IPyC failure predictions are obtained with Weibull statistics approximately 38 days after beginning of irradiation. After crack formation, hoop stress concentrations are predicted in SiC using conservative assumptions, with failure probability increasing to 3.3⋅10−4%. 2D BISON simulations of the base irradiation are then carried out to the maximum burnup and transient conditions are subsequently applied. SiC maximum tensile hoop stress is predicted at the time of crack initiation, after which crack expansion reduces the predicted stress magnitude in the material. The results presented in the work are interpreted under the selected modeling assumptions and conclusions are based on a comparison with a parallel analysis on a High-Temperature Gas-Cooled Reactor design to evaluate the effects of power density and burnup on SiC performance.

Effect of Surface Finishing State on Fatigue Strength of Cast Aluminium and Steel Alloys

The endurance limit of structural mechanical components is affected by the residual stress state, which depends strongly on the manufacturing process. In general, compressive residual stresses tend to result in an increased fatigue strength. Post-manufacturing processes such as shot peening or vibratory finishing may achieve such a compressive residual stress state. But within complex components, manufacturing-process-based imperfections severely limit the fatigue strength. Thus, the interactions of imperfections, residual stress state and material strength are key aspects in fatigue design. In this work, cast steel and aluminium alloys are investigated, each of them in vibratory finished and polished surface condition. A layer-based fatigue assessment concept is extended towards stable effective mean stress state considering the elastic–plastic material behaviour. Murakami’s concept was applied to incorporate the effect of hardness change and residual stress state. Residual stress relaxation is determined by elastic–plastic simulations invoking a combined hardening model. If the effective stress ratio within the local layer-based fatigue strength is evaluated as critical distance value, a sound calculation of fatigue strength can be achieved. Summing up, the layer-based fatigue strength design is extended and features an enhanced understanding of the effective stabilized mean stress state during cyclic loading.

Effect of stress-states on non-classical twinning in three-point bending of magnesium alloys

The influence of stress state on the drivers of non-classical twin nucleation in three-point bending of Magnesium alloy AZ31 is presented in this study. Deformed microstructures and textures at the tensile and, for the first time, shear regions are investigated in detail. The experimental observations coupled with the strain-gradient crystal plasticity analyses show that the shear nucleates more twins compared to the tensile and compressive stress-states at near yield-point. Stored energy density provides mechanistic insight into the local drivers of non-classical twin nucleation observed in the shear stress-state region. Further, the twin variant selection follows the locally stored shear energy density criterion, as opposed to the twin resolved shear stress, indicating that their nucleation is driven by local energy and defect sources.

Numerical analysis of residual stresses induced by cold spray fabricating cBN-reinforced Ni matrix composites

Metal particles used as cold spraying feedstock undergo severe plastic deformation during application. During this process, residual stresses are generated. The presence of porous metal particles and ceramic particles further complicates the deformation process. Numerical models have been proposed to describe the formation process for residual stresses induced by cold spray fabricating cBN-reinforced Ni matrix composites on a 42CrMo substrate. The feedstocks to be sprayed are mixtures of porous Ni particles and Ni-coated cBN particles. The analysis of residual stresses for the cBN-reinforced Ni matrix composites was accomplished by depositing cBN particles on the cold-spayed porous Ni particles and multi-layered Ni coatings. Firstly, local residual stresses are generated near the large number of closed pores inside the cold-sprayed porous Ni particles. Simultaneously, the residual stresses at the bottom of the multi-layered Ni coatings are changed from a compressive stress state to a tensile one as the number of cold-sprayed Ni layer increases. Finally, the deposited cBN particles aggravate the transformation of residual stresses during the cold spraying fabrication of multi-layered cBN-reinforced Ni matrix composites. The concentrated compressive stresses are generated when the cBN particles are deposited on the Ni particles. Understanding these phenomena may provide a guideline for tailoring the residual stresses for cold-sprayed cBN-reinforced Ni matrix composites and thereby improve service performance.

Influence of Several Heat Treatments on Residual Stress in Laser Powder Bed-Fused Maraging 18Ni-300 Steel

In laser powder bed fusion, process-inherited thermal residual stress is developed due to the thermal strain misfit between each layer. Detailed analysis and a prediction of the residual stress are needed because it can induce distortions of the components and, in some serious cases, stress-induced defects such as cracking. In this work, the effects of heat treatment conditions on residual stress in maraging 18Ni-300 steel, fabricated by laser powder bed fusion, were investigated. Cantilever-shaped specimens were used to experimentally analyze residual stress caused by the distortions of the specimens while cutting them from the supporters. The cantilever samples showed complex distortion behavior in the as-built state. They bent downward while cutting them from the supporter when the thickness was relatively thin, and the bending deformation became upward instead of downward with increasing thickness. Interpreting this behavior by finite element simulation showed that the downward bending was due to the compressive stress state at the top layer of the maraging steel. When the cantilever specimens were aging heat treated, the distortions were significantly reduced, implying that the process-inherited residual stress was diminished.

Influence of intermediate principal stress ratio on strength and deformation characteristics of frozen sandy soil under different moisture contents

Frozen ground often contain non-uniform moisture content and are under true triaxial stress state and their practical engineering application are still explored. The present study is carried out to investigate the strength and deformation characteristics of frozen soil with different moisture contents under true triaxial stress state conditions. A series of true triaxial tests were conducted on frozen soil specimens having constant minimum principal stress (σ3) and constant intermediate principal stress ratio (b). The experimental test results showed that the stress-strain curves represent the strain-hardening characteristics under different test conditions. The intermediate principal stress ratio (b) has a dual effect of strengthening and weakening on the strength of frozen sandy soil. When 0 ≤ b ≤ 0.5, the strengthening effect was found to be dominant in the frozen soil specimen, whereas, the weakening effect was dominant when 0.5 < b ≤ 1. The strength of frozen soil under true triaxial stress state is 8.18% to 36.33% higher under different water content conditions, compared to that under generalized triaxial compression stress state. The difference in deformation between the direction of the intermediate principal stress and the minimum principal stress increased with the increment in the intermediate principal stress ratio value. The volumetric strain in the soil sample initially exhibited the characteristics of shear contraction and then shear dilation.

Determination of stress in thin films using micro-machined buckled membranes

In this work, optical profilometry and finite-element simulations are applied on buckled micromachined membranes for the stress analysis of ion-beam-sputtered Ta2O5 and SiO2 thin films. Layers with different thicknesses are grown on silicon substrates, and then several membranes with different geometries are manufactured with standard microsystem technologies; due to a high level of films’ compressive stress, buckled membranes are obtained. Thermally grown silica membranes are also produced for comparison. The residual stress values are determined by comparing the measured and simulated deflections of the membranes. The average stress state of Ta2O5 thin films is found to be −209 MPa. The SiO2 thin films are in a higher compressive stress state whose average value is −576 MPa. For comparison, the average stress in thermal SiO2 thin layers grown at 1130°C is found equal to −321 MPa, in good agreement with the literature.

Effect of geometric deviations on the strength of additively manufactured ultralight periodic shell-based lattices

Lightweight shell-based lattice structures with various multifunctional applications can be fabricated with limited manufacturing constraints, thanks to the advancements of additive manufacturing technologies. However, there is always a geometric deviation between the 3D digital model and the additively manufactured lattice structure. In some cases, the geometric deviations may be as small as the machine accuracy, but they would cause a significant decrease in the strength of the lattice. In other cases, the lattice may not be so sensitive to geometric deviations. The sensitivity of lattice structures to the geometric deviations depends on their constituent material, loading condition, relative density, and the geometry of the unit-cell. To understand this, buckling failure should be considered beside yielding. This paper presents a local failure analysis of the ultralight shell-based lattices and explores the effects of the aforementioned factors on their strength and failure mechanism under compression. The main finding of this research is that unlike the high-relative density lattices, which are not sensitive to geometric deviations, in the design of ultralight shell-based lattices (with relative densities lower than 26 %), beside the loading conditions, the constituent material and relative density should be considered, as well. For example, for a 10 % relative density lattice designed for a triaxial compressive macroscopic state of stress, if the base material is stainless steel, the minimal surface is the optimal unit-cells, while if it is made of pyrolytic carbon, a constant mean curvature surface with a certain value of mean curvature other than zero is optimal. However, for shell-based lattices with relative densities higher than 26 %, the geometric deviation does not influence the lattice strength and thus the optimal geometry can be designed without regard to the base material and relative density.

Effects of tensile and compressive stresses on damage evolution law of nuclear graphite

Nuclear graphite, a quasi-brittle material containing microdefects, is essential for constructing the neutron moderators, reflectors, and cores in very-high-temperature gas-cooled reactors. Such reactors are prone to damage during loading, resulting in the failure of nuclear graphite materials or structures and possibly affecting the integrity of the entire core structure. Therefore, the damage evolution law of nuclear graphite should be studied while assessing the safety of the core. In addition, considering the different mechanical characteristics of quasi-brittle materials under tensile and compressive stresses as well as the complex stress states of quasi-brittle nuclear graphite structures in the core, the effects of stress states on the damage evolution law of nuclear graphite should be unveiled. These aspects are difficult to evaluate owing to the complexity of damage characterisation and measurement throughout the test loading of nuclear graphite under different stress states. Therefore, we propose damage measurement tests of nuclear graphite under unidirectional tensile and compressive stress states based on digital image correlation to obtain damage evolution laws under different stress states. By analysing the effects of different stress states on the damage evolution laws of nuclear graphite, we found that the damage properties under unidirectional tensile and compressive stresses show variations and that damage more likely occurs under tensile stress.

Failure analysis of Al2O3–C–SiO2 slide gate plates during continuous casting based on numerical simulation

The thermo-mechanical and failure behavior of the burning-free Al2O3 –C–SiO2 slide gate plate materials during the steel casting process are investigated. Firstly, the instantaneous coefficient of thermal expansion and the Young's modulus of the slide gate plate materials with different component contents at high temperature are measured. Secondly, a material constitutive model and a concrete damage plasticity mode are established based on the experiments, and adopted to simulate the failure behavior of the burning-free Al2O3–C–SiO2 slide gate plate during casting based on Finite Element Method (FEM) analysis. Results show that temperature gradient in the slide gate plate near the casting hole increased significantly and had a significant influence on cracking. The area near the casting hole of the slide gate plate is under tensile stress conditions, and then changes towards compressive stress conditions. Under those severe thermal stress conditions, crack formation is evaluated and an optimized composite structure of the slide gate plate combining advantages of reducing the risk of cracking and extending the service life is proposed. Moreover, the thermal shock test further verified that the microcrack extension was significantly alleviated due to the SiC distributed in whisker form and formed an interlocking structure in material. This work provides a reliable theoretical and experimental basis for the design and optimization of high performance Al2O3–C–SiO2 slide gate plates.

The bond-behaviour of CFRP-to-concrete bonded joints under fatigue loading: A damage accumulation model

This paper presents a theoretical study aimed at predicting the behaviour of carbon fibre reinforced polymer-to-concrete bonded joints under fatigue-cyclic loading. A model considering the plastic deformations of the interface, the damage, and the damage accumulation due to fatigue-cyclic loading is proposed. The damage accumulation model is calibrated through the experimental bond-slip relation. Then, a numerical algorithm is formulated to simulate the fatigue bond behaviour using the calibrated damage accumulation model. Numerical simulation was found to provide conservative predictions for fatigue life, which was attributed to the neglect of beneficial effects from the compression stress state near the loaded end in the single-shear pull-off test.

Design and Characterization of 2.5D Nature-Inspired Infill Structures under Out-Plane Quasi-Static Loading Condition

The 2.5D (2.5-dimensional) structures are acquired to enhance safety and lightweight designs with better energy absorption in the aerospace and automobile sectors. Additive manufacturing (AM), which is practical to build suitable components in industrial and transportation applications, may produce these structures more efficiently. The current study aims to improve the 2.5D infilled structures mean crush force (MCF) and energy absorption capabilities. Under compression loading, the proposed novel nature-inspired 2.5D infilled structure is compared to six existing 2.5D geometries that are inspired by nature. These structures are made of cylindrical shells that are filled with various infill configurations and maintained at a consistent volume. Photopolymer resin is used as the material for the structures, which are created using a digital light processing (DLP) method under AM technology. The characterization of the constructed models was done under compressive out-plane quasi-static stress conditions. ANSYS numerical simulations have been carried out to confirm the dependability of experimental data. The impact of supporting ribs and infill designs on crushing behaviour is thoroughly discussed. Mean crush force (MCF) and specific energy absorption (SEA) under quasi-static compression loading are provided to the proposed unique nature-inspired 2.5D infilled structure to significantly boost crushing qualities, axial collapse, and energy absorption behaviours.

A Three-Dimensional Analytical Solution of Stress Field in Casing-Cement-Stratum System Considering Initial Stress State

Accurate stress field calculation of the casing-cement-stratum system is crucial for evaluating wellbore integrity. Previous models treated in-situ stress as boundary pressure loads, leading to unrealistic infinite displacements at infinity. This study presents a three-dimensional (3D) analytical solution for the stress field within the casing-cement-stratum system in inclined wells, considering in-situ stress and hydrostatic stress in cement as the initial stress state and taking into account stress components related to the axial direction. Assuming a plane strain condition and superimposing the in-plane plane strain problem, elastic uni-axial stress problem and anti-plane shear problem, a 3D analytical solution is obtained. Comparisons with previous models indicate that the existing model overestimates the absolute values of stress components and failure potential of casing and cement in both 2D and 3D scenarios. The presence of initial stress in cement greatly increases the absolute value of the compressive stress state but decreases the failure potential in cement, which has not been well studied. Additionally, a low Young’s modulus and high initial stress state of the cement benefits the cement’s integrity since the maximum Mises stress significantly decreases. The new 3D analytical solution can provide a benchmark for 3D numerical simulation and quick assessment for wellbore integrity.

Effect of stress state on adiabatic shear banding in Al2024-T351

Cubic uniaxial compression and angled cubic biaxial shear-compression specimens are a preferable choice in the context of developing empirical data for models such as the Generalized Incremental Stress State Dependent Damage Model (GISSMO), with a strain-rate dependent extension. The angled cubic specimens introduce a multiaxial stress state of combined shear and compression. Al2024-T351 specimens have been impacted using a direct impact Hopkinson bar coupled with Digital Image Correlation (2D-DIC). 2D-DIC has been used to track the full-field strain evolution of all specimens and obtain the fracture strains for fractured specimens. The shear strain evolution related to failure along the shear planes can be acquired using 2D-DIC, and a quantitative measurement of fracture initiation is acquired from the DIC data. It is also highlighted that the transverse displacement contours can offer qualitative information about the effects of friction on proportional loading during uniaxial compression. Interrupted tests using stop rings are conducted for angled cubic specimens to identify the critical strains for the initiation of adiabatic shear bands (ASBs), which can be defined as the GISSMO instability strains. ASBs are confirmed using the optical microscope, and it is found that for a constant impact momentum, the specimens with a greater shear to compressive stress state exhibit a higher tendency to form ASBs at lower major axial strains. It is also found that ASBs are observed using the optical microscope with no loss of flow stress, and that angled specimens exhibit a lower flow stress than uniaxial compression specimens at higher strain rates. Lastly, pre-impact and non-fractured post-impact Vickers microhardness tests have been conducted, and it is found that for all specimens, the material is on average about 20% harder after impact in regions away from the ASB, and further that regardless of stress-state, the ASB is consistently about 30% harder than the pre-impact microstructure.

On the Hot Deformation of a Fe-Al-Ta Iron Aluminide Prepared via Laser Powder Bed Fusion

In the present work, a combined process of laser powder bed fusion (LPBF) and hot working in terms of microstructure refinement was investigated for Fe-25Al-1.5Ta alloy samples. Uniaxial compression tests were carried out parallel and perpendicular to the building direction (BD) at 1000 °C, where BCC A2-phase was stable, at a strain rate of 0.0013 s−1. The true stress–true strain curves indicated a broad flow stress peak followed by a slight decrease, which is typical for dynamic recrystallization (DRX) of conventional BCC metals such as ferritic iron. A negligible dependence in the flow stress behavior on the compression direction was observed. DRX initiated at a stress of 18.7 MPa for the sample compressed parallel to the BD, corresponding to a true strain of 0.011, and at 18.1 MPa for the samples compressed normal to the BD, which corresponded to a true strain of 0.010. The microstructural investigations by electron backscatter diffraction (EBSD) showed that the relatively coarse and elongated grains of the as-LPBF builds were significantly refined after hot working. The microstructure of the compressed samples mainly consisted deformed grains. These were fragmented by sub-grains bounded by low-angle boundaries independent of the compression axis, indicating the occurrence of dynamic recovery (DRV) during hot working. In addition, a few equiaxed, small grains were observed in the pre-existing grain boundaries, which formed due to DRX. Most pores in the as-LPBF builds were closed after hot compression, particularly in the central region of the deformed specimens where the compressive stress state is dominant. In summary, hot compression reveals a practical thermomechanical post-processing treatment for Fe-Al-Ta iron aluminides built by LPBF. The hot working refines the epitaxially elongated microstructure of the as-LPBF builds by DRV/DRX and reduces the porosity.

Medium-range order endows a bulk metallic glass with enhanced tensile ductility

Developing ductile bulk metallic glasses (BMGs) can benefit from an in-depth understanding of the structure-property relation during plastic deformation. However, endowing BMGs with tensile ductility in BMGs needs to reveal the response of critical structure units during deformation. Here, we report the experimental results of an in-situ synchrotron high-energy X-ray study of a Zr-based BMG under uniaxial tension after preprocessing by canning compression of the three-dimensional compressive stress state. It is revealed that the canning-compressed BMG (CC-BMG) sample has better tensile ductility and higher ultimate strength than the as-cast sample, which possesses heterogeneous and loosely packed local structures on medium-range scales. The experimental results revealed two stages of plastic deformation in the CC-BMGs compared with one stage of plastic deformation in the as-cast BMG. Moreover, the shift in the first sharp diffraction peak along the tension direction for the canning-compressed sample is substantially more pronounced than that of the as-cast sample. Furthermore, the real-space analysis illustrates a competition mechanism between the 2-atom and 3-atom connection modes on medium-range order during the plastic deformation of the CC-BMG. Additionally, the ordering on the medium-range scale decreases in the first plastic deformation stage but increases in the second plastic deformation stage. Therefore, a structural crossover phenomenon occurs in the CC-BMG during plastic deformation. Our results demonstrate a structure-property correlation for the CC-BMGs of heterogeneous medium-range ordered structures, which may be beneficial for endowing BMGs with ductility based on medium-range order engineering techniques.