Fracture Mechanics Research Articles

Superalloys fracture process inference based on overlap analysis of 3D models

Superalloy materials exhibit susceptibility to fracture failures stemming from the influence of thermomechanical factors. To comprehensively understand the fracture mechanisms, material properties, root causes of failure, and the subsequent optimization of alloys, a detailed analysis of the internal fracture process and the morphological traits of the fracture surface is imperative. Traditional analysis of fracture surfaces solely relies on 2D images, thus lacking crucial 3D information. Although in situ experiments can capture the fracture process, their effectiveness is confined to the specimen’s surface, precluding insight into internal changes. Here we introduce an integrated framework encompassing the process of 3D reconstruction of fracture surfaces, aiming to enhance the visual information obtained with micron-level accuracy, visual intuitiveness and sense of depth. Additionally, this framework also facilitates the scrutiny and inference of internal fracture processes. These results demonstrate that under specific service conditions, material deformation fracture probably stems from a combination of surface cracking and internal cracking rather than exclusively one or the other. Overall, our description and analysis of internally initiated cracking due to defects within the specimens can be beneficial in guiding future alloy design and optimization efforts.

Pediatric Facial Fractures: A Multi-Institutional Level 1 Trauma Center Analysis of Incidence, Interventions, and Outcomes

Study Design Retrospective chart review. Objective The management of pediatric facial fractures presents distinctive considerations compared to adults. This study aims to provide a unique perspective on the correlations between the mechanism of injury, types of facial fractures, and fracture interventions and management utilized in 2 North Carolina Level 1 Trauma Centers to determine the optimal management options for this patient population. Methods An IRB-approved retrospective chart review was performed of pediatric facial trauma patients ages <18 years old between January 2020 and December 2022 at Atrium Health Wake Forest Baptist Medical Center and Atrium Health Charlotte Medical Center. Data on patient demographics, mechanism of injury, facial fractures, interventions, and outcomes were collected. Results Of 2,977 pediatric facial trauma patients, 582 patients sustained at least 1 facial fracture at the time of injury. Adolescents were significantly less likely to be transferred from outside institutions and to be admitted for further care ( P = 0.002). Adolescents experienced higher levels of residual symptoms following initial discharge ( P = 0.001) and were less likely to have a symptom resolution within 1 year ( P < 0.0001). Neonates and infants were significantly more likely to receive conservative interventions and to sustain calvarium and skull base fractures ( P < 0.0001). Conclusions This study identifies differences in pediatric age groups related to transfers, admittance, fracture type, management, and outcomes. Our data suggests adolescent patients may experience a higher incidence of residual symptoms with lower levels of symptom resolution within 1 year. Further investigation into these differences may elicit optimized methods of fracture management in pediatric age groups and allow for effective, individualized care with improved long-term outcomes.

Unraveling Ice-Solid Interface Rupture Dynamics: Insights from Molecular Dynamics Simulations.

Unwanted icing on exposed surfaces poses significant risks, driving the quest for effective anti-icing mechanisms. While fracture mechanics concepts have been developed for designing coatings that weaken the ice-solid interface on soft surfaces, the factors that dictate ice adhesion strength and its counterpart, ice removal force, on hard surfaces remain poorly understood. In this study, we employ molecular dynamics simulations to investigate the interface rupture between ice and a hard solid substrate. The results indicate that the ice adhesion strength is contingent on the length of the ice cube. By examining the shearing behavior, we reveal a nanoscale critical force-bearing length. The shear force required to detach the ice scales proportionally with the length of the ice cube when it is smaller than the critical length. Once the ice cube length exceeds the critical length, the shear force stabilizes at a constant maximum value, revealing the existence of a maximum ice-removal force. The results align with the so-called strength versus toughness-controlled deicing regimes and are in agreement with cohesive zone modeling at the continuum length scale and recent experimental results. Our results extend this understanding to the nanoscale, confirming consistency between macro and micro scales. This consistency suggests that the toughness of the ice-solid interface is intrinsically governed by ice-surface interactions. By unraveling key intrinsic factors and their scale-dependent effects on the interface rupture of ice on surfaces, this study lays a solid theoretical foundation for the design and fabrication of next-generation anti-icing surfaces.

Influence of γ‐irradiation dose on the mechanical and tribological properties of fluoroelastomer

AbstractFluoroelastomer (FKM) undergo various degrees of degradation in a gamma‐irradiated environment, leading to changes in their mechanical and tribological properties. In this paper, changes in the properties of FKM were investigated for six different doses. Fourier transform infrared‐atomic absorption spectroscopy (FTIR‐ATR) results show that FKM samples undergo dehydrofluorination and oxidation reactions during irradiation, resulting in the formation of C=C, C=O, and ‐OH functional groups. The results of the swelling test showed that the degree of cross‐linking of the FKM specimens increased with increasing irradiation dose. Mechanical test results show that the fracture mechanism of FKM specimens gradually evolves from ductile fracture to brittle fracture with the increase of irradiation dose. Its tensile strength reaches its maximum at an irradiation dose of 1000 kGy, and the modulus of elasticity becomes larger with increasing irradiation dose. The results of wear tests show that the average coefficient of friction of FKM specimens first decreases, reaches a minimum at 500 kGy, and then gradually increases. The amount of wear increases with increasing irradiation dose. The wear mechanism of FKM specimens is abrasive wear at 0–500 kGy, adhesive wear at 1000 and 2000 kGy, and fatigue wear at 3000 kGy.Highlights FKM was irradiated by gamma‐ray with a total dose of 3000 kGy. Dehydrofluorination and oxidation reactions occur during irradiation. Increased cross‐linking leads to changes in mechanical properties. The wear mechanism of FKM with different doses has been investigated.

Mechanical properties and water vapour corrosion behaviour of Al x CoCrFeNi high-entropy alloys.

Al x CoCrFeNi (x = 0.1, 0.5 and 1) high-entropy alloys (HEAs) were prepared using a spark plasma sintering (SPS) technique combined with aerosol powder. Their microstructure and phase constituents were characterized using an X-ray diffractometer and SEM, and their tensile properties, hardness and compactness were tested. The results show that the crystal structure of the Al x CoCrFeNi HEAs changed significantly with the Al content, from the original single face-centered cubic FCC phase (Al0.1CoCrFeNi) to an FCC + BCC structure (Al0.5CoCrFeNi), and then to FCC + BCC + sigma (σ) phase structures (AlCoCrFeNi). Chemical composition analysis showed that the crystal structure transformation was related to the segregation caused by the increased Al content. The hardness of the Al x CoCrFeNi HEAs increases with increasing Al content, and the hardness of AlCoCrFeNi reaches a maximum of 507.3 HV. The tensile properties of the alloy show a trend of first increasing and then decreasing with increasing Al content, and the yield strength, ultimate tensile strength and elongation of the Al0.5CoCrFeNi alloy reach maximum values of 527.4 MP, 943.3 MPa and 28.2%, respectively. The fracture mechanism of the Al0.1CoCrFeNi and Al0.5CoCrFeNi alloys is typical ductile fracture, while that of the AlCoCrFeNi alloy is cleavage fracture. The compactness of the alloy increases with the Al content. The samples were also subjected to high-temperature water vapour corrosion, and corrosion products such as Al3Fe5O12, CoCr2O4 and NiCr2O4 were found in the Al0.1 and Al0.5 alloys, whereas no oxide peaks were detected using XRD for the Al1 alloy. It was also presumed that a very thin alumina film was generated on the surface of the Al1 alloy, preventing the oxidation of the sample, in combination with the analysis of SEM, EDS and XPS behaviour.

Effect of hollow glass microspheres on transverse properties of carbon fiber reinforced epoxy composites

AbstractHollow glass microsphere (HGM)—based composites are gaining popularity in materials research due to their ability in altering material characteristics drastically. The current study investigates HGMs filled carbon fiber reinforced epoxy (CE) composites on transverse properties, aiming for aerospace and defense applications mainly in composite pressure vessels. Unidirectional laminates of Carbon/Epoxy with varying HGM percentages (0.2, 0.4, 0.6, 0.8, 1.0 wt. %) were wounded onto a flat‐plate mandrel using a 4‐axis filament winder, along with a baseline sample without HGM for comparison. The glass transition temperature (Tg) and thermal stability were analyzed by carrying out dynamic mechanical analysis and thermogravimetric analysis. The fracture mechanism of the samples loaded under tension was investigated using FESEM. Experimental results indicate reduction in density with increase in HGM content, up to 0.4% HGM there is increase in transverse tensile strength of 25% compared to baseline and further increase in HGM content, decrease trend is observed. 30% decrease in transverse compressive strength is observed compared from baseline to 1.0 wt. % of HGM. No significant change was noticed in the thermal stability and Tg on introduction of HGM. Microscopy images of fractured samples revealed effective physical interaction and dispersion of the HGM within the matrix.Highlights Transverse mechanical properties are tested to know the influence of HGM filler on filament wound composites. Density of the composite decreases with increase in HGM content. Thermal stability and Tg shows less change on introduction of HGM in composites.

Advanced Mechanical Transfer of Micro-LEDs Enabled by Structurally Modified Wide Sapphire Nanomembranes through Thermal Reflow of Photoresist.

Micro light-emitting diodes (micro-LEDs) are pivotal in next-generation display technologies, driven by the need for high pixel density. This study introduces a novel methodology utilizing wide sapphire nanomembranes (W-SNM) as a dual-purpose template for high-quality epitaxial growth and the mechanical lift-off of individual micro-LEDs. Micro-LEDs grow individually on W-SNM, obviating the chip singulation process. By employing mechanical fracturing of the thin W-SNM, our method facilitates the transfer of micro-LEDs without the conventional laser lift-off (LLO) process. Previously introduced sapphire nanomembranes (SNM) have shown promise in enhancing epitaxial layer quality; however, they encountered challenges in managing micro-LED size variation and achieving efficient mechanical transfer. Here, we apply simple yet effective adjustments to the SNM structure, specifically, its elevation and widening. This strategic modification allows micro-LEDs to endure applied forces without incurring cracks or defects, ensuring that only the targeted W-SNM are selectively fractured. The mechanically transferred vertical 15 × 15 μm2 micro-LED device operates at an optimal turn-on voltage of 3.3 V. Finite element simulations validate the mechanical strain distribution between the W-SNM and GaN when pressure is applied, confirming the efficacy of our design approach. This pioneering methodology offers a streamlined, efficient pathway for the production and mechanical transfer of micro-LEDs, presenting new avenues for their integration into next-generation, high-performance displays.

Risk-based method for substantiating reduction of pressure of hydraulic strength tests and its application on steam line of nuclear power plant with WWER (PWR) reactor plant

Hydraulic tests are used in various sectors of the national economy to check the strength and tightness of vessels and pipelines, their parts and assembly units loaded with pressure. The hydraulic test pressure is a calculated value and is determined on the basis of regulatory documentation for the relevant control objects. Analysis of current trends in the field of hydraulic testing both in the Russian Federation and abroad has shown a trend to reduce the damageability of test objects by choosing the most optimal hydraulic test pressure. The main purpose of the research was to reduce the operational damage to equipment and pipelines of nuclear power plants by reducing the pressure of hydraulic strength tests during maintenance. The research is based on probability theory, mathematical statistics, strength physics and fracture mechanics, taking into account the possibility of occasional discontinuities or defects that might be observed in operation. The method is based on a risk-based approach, which makes it possible to determine the permissible risk variation based on recommendations on the safety of nuclear power plants in the Russian Federation. The objects of research are the equipment and pipelines of nuclear power plants. The result of the research is the development of a method substantiating the reduction of the pressure of hydraulic strength tests for equipment and pipelines of nuclear power plants based on a risk-based approach. The developed method can be used by organizations involved in the production of electricity (at nuclear or thermal power plants), transportation of oil, gas or other substances, at facilities where pipelines are an essential part of their structures, affecting the reliability and efficiency of operation of these facilities.

Achieving ultrastrong adhesion of soft materials by discretized stress dispersion

The adhesion of soft materials often fails due to stress concentration at the interface. Structural design offers an effective approach to disperse stress at the interface and enhance adhesion properties. Herein, we introduce the concept of discretized stress dispersion to achieve ultrastrong adhesion of soft materials. This involves incorporating discrete structures at the adhesion interface, with each unit structure designed to efficiently disperse stress. We implement this concept by introducing periodic strategic cuts into the adhesive, enabling it to deform into discrete mushroom-shaped structures under peel forces. Utilizing fracture mechanics theory, we demonstrate that such structural design can significantly improve adhesion strength compared to adhesives without structural design. Through 3D printing, we fabricate adhesive samples with strategic cuts, achieving a peak peel force of 3479 N/m, over 100-fold higher than adhesives without cuts (25 N/m). We analyzed stress dispersion of each unit structure through experiments of with different geometric parameters and analyze collaborative effects of multiple structures with theoretical model. Finite element analysis of the peel process highlights the critical role of cohesive zone influenced by geometric parameters, which determines the peak peel force. This concept of discretized stress dispersion advances the development of soft materials with ultrastrong adhesion.

On the anisotropic fracture behaviour of AA2050-T84 thick plate

Anisotropy in the fracture behaviour of AA2050-T84 was investigated using 2D digital image correlation (DIC)-assisted 3-point bending fracture toughness test on specimens with crack propagation direction oriented along the normal direction (ND) and rolling direction (RD). The tensile properties along the RD indicated slightly higher yield strength (482 ± 8 MPa) than ND sample (469 ± 9 MPa), while the fracture toughness in terms of energy release rate was higher when the notch was oriented along the ND (35.3 ± 1 kJ/m2) compared to the RD (18.5 ± 0.9 kJ/m2). Fractography of the fractured surfaces and detailed electron backscatter diffraction (EBSD) analysis of the microstructure along crack paths unveiled higher crack tortuosity with extensive secondary cracking in the TD-ND specimen than in the TD-RD. DIC measurements clearly showed a larger deformation zone for the TD-ND specimen also as which corroborated the plastic zone size determined using linear elastic fracture mechanics (LEFM). Additionally, the crystallographic model of tilt and twist angle differences between the neighbouring grains was employed to explain the increase in crack path tortuosity and higher dissipation of plastic work contributing to superior fracture toughness for the TD-ND sample.

Effect of lubricants during the rolling process on the mixed mode fracture behavior of the as-rolled material

Friction is one of the major factors in energy consumption and metal depreciation during various mechanical processes. Lubrication is often used during the process of forming metals to cope with friction and its consequences. Mineral lubricants are employed in the rolling process to decrease the rolling force and enhance the quality of the sheets. This research aims to compare the performance of mineral lubricants such as crude oil, gas oil, and CM405A to enhance the production efficiency of the aluminum forming process, especially in the rolling process. The ring compression test was utilized to evaluate the influence of lubrication on the friction coefficient which was extracted through calibration curves. Then, the effect of friction coefficient was experimentally examined during the forming process through rolling. Al 1050 was rolled by the mentioned lubricants. The pre-cracked rolled samples were then tested by fracture test at different loading angles of 0 (pure mode-I), 45(mixed-mode of I and II), and 90(pure mode-II). J-R curves were extracted using elastic–plastic fracture theory based on material characteristics. The fracture tests indicated maximum resistance to crack growth occurred in the sample prepared with CM405A lubricant. In contrast, the lowest crack growth resistance was recorded in the case where crude oil was employed as a lubricant. In the end, the SEM images of the fractured surfaces were explored for a deeper understanding of the fracture behavior. Although a combination of brittle and ductile fracture mechanisms can be observed on the fractured surfaces, cleavage was the dominant phenomenon and fracture mechanisms.

Carbon distribution in lath martensite and quench embrittlement

Effect of water quenching and low-temperature tempering (LTT) at T≤280 °C on fracture mechanisms upon tension and during the Charpy V-notch (CVN) impact test of 0.53%C-1.6%Si-0.9%Mn-0.76%Cr-0.14%V-0.05%Nb steel was studied. The steel exhibits quench embrittlement (QE). Tensile specimens fractured in elastic region after quenching due to easy crack initiation by intergranular fracture mechanisms. CVN impact toughness was ~5 J/cm2. Low fracture toughness is attributed to superposition of intergranular fracture and transgranular quasi-cleavage fracture within packets during crack propagation; crack initiation occurs locally at the notch surface. QE is attributed to carbon segregations on high-angle boundaries if a sufficient portion of bulk carbon could not be consumed for the formation of Cottrell clouds on dislocations. LTT provides precipitation of transition carbides that leads to depletion of carbon from martensite and boundary segregations that decreases severity of QE due to suppression of intergranular fracture, increase of fracture brittle stress and contribution of dimple fracture to overall fracture process. The onset of fracture takes place after yielding in tension and fracture toughness increases by a factor of ~2 after LTT.

Effect of subgrain microstructure on the mechanical properties of Invar 36 specimens prepared by laser powder bed fusion

Invar 36 samples were fabricated via laser powder bed fusion (LPBF) at various energy densities. In this work, a parameter range for the preparation of full-density Invar 36 samples was determined. The microstructural evolution and tensile properties of the materials were studied in the as-LPBFed state, and the role of subgrain structures on the fracture mechanism was investigated. According to the results of this analysis, as the energy density increased, the density first increased and then decreased. The maximum density (99.94%) reached 65J/mm3, and the simple density reached full density at 40–90J/mm3. Due to constitutional supercooling, the microstructure of the alloy is composed of cellular subgrains and columnar subgrains. Columnar subgrains grow perpendicular to the boundary of the molten pool to the center of the molten pool, while cellular subgrains primarily exist in the remelting area of the molten pool. In the full density range, the ultimate tensile strength of the samples reaches 437–484MPa, and differences in the morphology, distribution, and micronicomechanical properties of the subgrains are responsible for the differences in macroscopic properties. At 40, 65, and 90J/mm3, the elastic moduli of the columnar subgrains are approximately 155.1GPa, 161GPa, and 162.4GPa, respectively; the elastic moduli of the cellular subgrains are approximately 136.2GPa, 140.2GPa, and 139.9GPa, respectively, which means that in the elastic deformation stage, the columnar subgrains are more resistant to elastic deformation; in the plastic deformation stage, different subgrains have different effects on crack propagation; the columnar subgrains grow perpendicularly to the melt pool boundary, which has a hindering effect on the extension of microcracks; and the cellular subgrains have a homogeneous grain size so that the microcracks can be easily extended along the cellular subgrain boundaries.

Tensile deformation and failure of AlSi10Mg random cellular metamaterials

Cellular metamaterials are an emerging class of porous materials, in which the topology of the solid is precisely-engineered to achieve attractive combinations of properties. This work specifically examines the tensile response of a novel type of cellular metamaterials, in which pores of arbitrary elliptical shape are randomly-dispersed into an aluminum alloy matrix. Their porous mesostructure is generated numerically via a random sequential absorption algorithm, and is fabricated by laser powder bed fusion from AlSi10Mg powders. The results – obtained by means of digital image correlation combined with X-ray tomography - highlight the advantages offered by a random cellular topology. These are notably a low sensitivity to geometric imperfections (which result inevitably from manufacturing), coupled with the ability to delay long-wavelength strain localization (which is in turn responsible for failure). Structural disorder also leads to highly heterogeneous deformation patterns, which result from the interaction between geometric pores and promote void growth and coalescence during plastic straining. The presence of manufacturing defects, moreover, exacerbates void interaction and in turn promotes early plastic flow localization. Interestingly, experiments reveal that this class of porous solids effectively display features of the ductile fracture of metals, albeit at the mesoscale. For example, void-sheeting is observed with increasing pore aspect ratio and is accompanied by large geometric distortions of the voids upon coalescence. Measured data for the pore strains are, moreover, highly scattered and show a departure from McClintock’s model predictions for the voids within the fracture band. Collectively, this study highlights the potential offered by random porous metamaterials, which can be harnessed to revisit the complex mechanisms of ductile fracture at the mesoscale.

Hydrogen accelerated nanopore nucleation, crack initiation and propagation in the Ni–Co superalloys

Influence of hydrogen at pressures up to 35 MPa (and absorbed hydrogen with concentration up to 32,7 ppm) on the nanopore nucleation, crack initiation and propagation in Ni–Co superalloys for disk application with different chemical composition and tempering modes has been investigated. It was established that under the influence of gaseous hydrogen, the tensile strength, true fracture stress, relative elongation, and reduction of area of disk alloys samples decrease both at room and close to operating temperatures (1073 K). The cyclic durability of the samples under the influence of prolonged exposure to high pressures and temperatures in the hydrogen gas environment decreases by about 3 times.We have discussed the mechanisms of hydrogen-assisted nickel-cobalt superalloys fracture on mesa-, macro-, micro-, and nano-levels.

Effect of the lateral area of graphene nanosheets on the strengthening mechanism in FGH96 superalloy composites

To improve the strengthening effect of graphene reinforcement in nickel-based superalloys, introducing graphene nanosheets (GNSs) with multiple lateral areas into the GNS/metal system is a promised strategy to take full advantage of the superior properties of graphene reinforcement. In this work, the impact of the GNS lateral area on the strengthening effect of FGH96 nickel-based superalloy composites (DLA-GNS/FGH96) was investigated for the first time. Microstructural and tensile tests revealed the uniform distribution of the GNSs in the DLA-GNS/FGH96 metal matrix with lateral areas ranging from 0.06 ± 0.02 to 225.2 ± 20.3 μm2. The GNSs exhibited a well-balanced mechanical property on the elongation and yield strength of the DLA-GNS/FGH96 composites. Investigation of the fracture morphology and mechanism indicated that there existed a transition of the strengthening mechanism (between the strengthening mechanism of Orowan and the strengthening mechanism of load-transfer) for the GNSs, which was closely associated with the lateral area of the GNSs. This finding put forward new ideas to better comprehend the strengthening mechanisms of GNS-reinforced metal-matrix composites.

Effects of nano-silica on fracture properties and mechanism analysis of basalt fiber reinforced concrete

The reinforcing effect of basalt fibers (BFs) on the performance of concrete mainly relies on the bridging effect of fibers, while recently, it has been shown that nano-silica (NS) may further enhance this effect. In this paper, three-point bending fracture tests were carried out on BF reinforced concrete (BFRC) to determine the optimal BF condition (i.e. volume content and length). Based on this optimal condition, the effect of NS content on the fracture performance of BFRC was examined from macroscopic and microscopic perspectives. The results indicate that the optimal BF condition for yielding the best concrete performance was 0.2% volume content and 6mm fiber length. Based on this condition, NS at 1% mass content could improve its fracture performance to the best extent. Specifically, the crack initiation toughness, unstable fracture toughness and fracture energy were 1.83 Mpa·m0.5, 3.35 Mpa·m0.5 and 364.42N/m, respectively, which were improved by 5.58%, 15.93% and 4.97% compared to BFRC. NS mainly affects the crack propagation mode of BFRC by enhancing the fiber bridging effect or altering the way BFs play a bridging role. NS at an appropriate mass content can delay the occurrence of cracks and improve the deformation ability of BFRC.

AlN reinforced Fe activated sintered tungsten matrix composites: Mechanical properties, fracture behaviors and reinforcement mechanisms

In this study, AlN particles were proposed as the reinforcement to prepare Fe activated sintered tungsten matrix composites. The results indicated that the AlN particles stably existed inside the W(Fe) matrix and exhibited a significant strengthening and toughening effect. Compared with the W(Fe) material, the maximum microhardness, flexural strength and fracture toughness of the composites were increased by 101.42%, 66.29% and 64.63%, respectively. An AlN content-AlN particle size-composite fracture mode map was constructed to classify the four fracture modes of the composites. In addition to the fine grain strengthening and residual stress strengthening, a novel “oxygen purification strengthening effect” was found, which resulted from the thin (Fe,Al)2O3 reaction layer formed at the AlN/W(Fe) matrix interface.

A new device and calibration method for the fracture energy testing of single-particle impact

This study presents a piezoelectric fast load cell (PFLC) as a novel device for testing single particle fracture energy under impact and proposes a collision model for measurement and calibration. The research examined various models, modifying the long-rod model to create a more practical short-rod model describing the contact dynamics during collision processes. Though back-calculating the Young's modulus of glass beads, the optimized measurement settings are calibrated for practical use based on the short-rod model, which is corroborated by comparison with fracture probabilities obtained from the drop weight tests and PFLC. It was verified that the observed fracture characteristics of ore align with established principles of fracture mechanics, validating the testing approach. The PFLC offers a cost-effective and compact substitute to classic ultra-fast load cell (UFLC), potentially enhancing the adoption of advanced comminution models like the Tavares Model.

Shear behavior of Cu/Al/Cu trilayered composites prepared by high-temperature oxygen-free rolling

The interfacial microstructure, interfacial shear properties, and shear fracture morphology of Cu/Al/Cu trilayered composites prepared by high-temperature oxygen-free rolling were studied, and the interfacial shear fracture mechanism was revealed. The results showed that the Cu/Al/Cu trilayered composites have a good metallurgical bonding interface. The interfacial microstructure is composed of Al2Cu, AlCu, and Al4Cu9. The intermetallics (IMCs) parallel to the rolling direction show discontinuous distribution, while the IMCs perpendicular to the rolling direction have mainly continuous distribution and occasional discontinuous distribution. The interfacial shear strength at room temperature can reach 68MPa, and when the test temperature rises to 350 °C, the interfacial shear strength drops sharply to 16.9MPa. The interfacial shear fracture mainly occurs in the low-strength Al layer due to the good metallurgical bonding interface. The IMCs near the shear fracture exhibit clear signs of cracking, and there is a phenomenon where the Cu layer embeds into the Al layer in a "sawtooth" shape. Meanwhile, shear fracture also occurs in the IMCs layer, and a small amount of Al will attach to the surface of the IMCs. However, the high bonding strength resulting from the excellent metallurgical bonding of the interface makes this type of shear fracture rare. The shear fracture of Cu/Al/Cu trilayered composites is mainly dominated by the fracture of the low-strength Al layer and the occasional fracture of the IMCs.