Local Stress Research Articles

Role of molecular damage in crack initiation mechanisms of tough elastomers

Tough soft materials such as multiple network elastomers (MNE) or filled elastomers are typically stretchable and include significant energy dissipation mechanisms that prevent or delay crack growth. Yet most studies and fracture models focus on steady-state propagation and damage is assumed to be decoupled from the local stress and strain fields near the crack tip. We report an in situ spatial-temporally resolved 3D measurement of molecular damage in mechanophore-labeled MNE just before a crack propagates. This technique, complemented by digital image correlation, allows us to compare the spatial distribution of both damage and deformation in single network (SN) elastomers and in MNE. Compared to SN, MNE have a wide-spread damage in front of the crack and, surprisingly, delocalize strain concentration. A continuum model, where damage distribution is fully coupled to the crack tip fields, is proposed to explain these results. Additional measurements of time-dependent molecular damage during fixed grips relaxation in the presence of a crack reveal that the less localized damage distribution delays fracture initiation. The observations and exploratory modeling reveal the dynamic fracture mechanism of MNE, providing guidance for rational design of high-performance tough elastomers.

Low Iron Diet Improves Clinical Arthritis in the Mouse Model of Collagen-Induced Arthritis.

Background: In response to inflammation, the absorption of nutritional iron is restricted. Since the pathophysiological significance of the presence and uptake of iron in chronic inflammation is still unknown, we tested the effect of a low iron diet on the clinical course of arthritis in the mouse model of collagen-induced arthritis (CIA). Methods: Six- to eight-week-old male DBA/1 mice were fed either a normal (51 mg/kg) or a low iron diet (5 mg/kg) starting four weeks before the first immunization. From day 4 after the second collagen booster made on day 25, the development of arthritis was regularly monitored until the end of the experiment (day 34), using a standard clinical arthritis score. Concentrations of mouse anti-bovine and anti-mouse collagen type 2 IgG antibodies were measured by ELISA; blood cell counts were performed and mediators of inflammation, tissue matrix degradation, oxygenation and oxidative stress were measured in the mouse sera of both diet groups at the end of the experiment by bead-based multiplex assay. Fe2+, Fe3+, oxidized and reduced glutathione (GSH and GSSG) and malondialdehyde (MDA) were quantified in whole paw tissue by ELISA. Quantitative PCR was performed in the tissues for glutathione peroxidase 4 and other key regulator genes of iron metabolism and ferroptosis. We used nonparametric tests to compare cross-sectional data. Nonlinear regression models were used for longitudinal data of the arthritis scores. Results: Mice fed a low iron diet showed a significantly less severe course of arthritis compared to mice fed a normal iron diet (p < 0.001). The immune response against bovine and mouse type 2 collagen did not differ between the two diet groups. Mice fed a low iron diet exhibited significantly lower serum levels of tissue inhibitor of metalloproteinase-1 (TIMP-1), a central regulator of inflammation and tissue matrix degradation (p < 0.05). In addition, a low iron diet led to a significant reduction in red blood cell indices, indicating restricted iron uptake and latent iron deficiency, but had no effect on hemoglobin concentrations or red blood cell counts. There were no differences between the dietary groups in Fe2+ or Fe3+ content in the paws. Based on calculation of the GSH/GSSG ratio and high MDA levels, high oxidative stress and lipid peroxidation were likewise detected in the paws of both diet groups of mice. Consequently, no differences associated with gene expression of key regulators of iron metabolism and ferroptosis could be detected between the paws of both diet groups. Conclusions: Restricted dietary iron intake alleviates immune-mediated inflammation in CIA without causing anemia. This finding suggests a promising option for dietary treatment of arthritis in inflammation. The underlying mechanism causing reduced arthritis may be linked to the complex regulatory network of TIMP-1 and appears to be independent from the local iron levels, oxidative stress and ferroptosis in the synovial tissues.

A simplified theoretical model to predict the shear behavior of concrete/rock joints with Gaussian irregularities

The inherent randomness in the roughness of concrete-rock joints poses challenges for analyzing their shear behaviour. Traditionally, theoretical models simplify these complex geometries by approximating them as regular triangular asperities. This study presents a novel micro-mechanical model developed to simulate the shear behaviour. The model accounts for the complex and random roughness of joint profiles by considering varying asperity heights as Gaussian distribution. Local stress distribution among individual asperities was determined. A failure envelope, mapping joint dilation against asperity height, was obtained, allowing us to identify the critical joint dilation for individual asperities at which individual asperity failure results. The parameter of shear area ratio, which captures the portion of failed asperities relative to all asperities, is introduced, and its semi-analytical solution was derived. Additionally, a wedge-shaped planar failure surface is determined based on laboratory observations and equations to estimate post-failure residual resistance is obtained. A series of direct shear tests on rock/concrete joints with a range of geometries was conducted to validate the proposed model and reasonably close agreement was obtained between predicted and measured performance. An additional case study analyzing the results of field tests on a drilled pile socketed in rock has been conducted using the proposed method. The results showed good agreement with the measured data, demonstrating the validity and practicality of the proposed approach.

Optimized designation of mesoscopic configuration of Zr/Ti layered metal composites for strength-ductility synergy improvement

Zirconium (Zr) and its alloys are highly promising for extreme service environments due to their excellent radiation and corrosion resistance. However, a major challenge in Zr-based materials lies in the strength-ductility trade-off, which limits their broader structural applications. This study aims to address this challenge by fabricating Zr/Ti layered metal composites (LMCs) with different layer thickness ratios (LTRs) and investigating the effects of LTR on the mechanical properties of Zr/Ti LMCs. Zr/Ti LMCs with varying LTRs were fabricated to explore how mesoscopic configurations influence their deformation mechanisms. The results reveal that an optimized layer thickness (∼50 μm for Zr and ∼40 μm for Ti) maximizes the hetero-deformation-induced (HDI) strengthening effect, resulting in a synergy improvement in strength and ductility. Stable and constrained cracks observed in the Zr layers contributed to local stress relief and improved ductility. The anisotropic deformation between the Zr and Ti layers transformed the local stress states into triaxial states. In addition, the localized stress state and inter-layer strain transmission also promote prismatic <a> slip near the interfaces. This study provides key insights into the design of Zr-based composites with improved mechanical performance, offering potential solutions for their application in demanding environments.

A finite element based approach for nonlocal stress analysis for multi-phase materials and composites

AbstractThis study proposes a numerical method for calculating the stress fields in nano-scale multi-phase/composite materials, where the classical continuum theory is inadequate due to the small-scale effects, including intermolecular spaces. The method focuses on weakly nonlocal and inhomogeneous materials and involves post-processing the local stresses obtained using a conventional finite element approach, applying the classical continuum theory to calculate the nonlocal stresses. The capabilities of this method are demonstrated through some numerical examples, namely, a two-dimensional case with a circular inclusion and some commonly used scenarios to model nanocomposites. Representative volume elements of various nanocomposites, including epoxy-based materials reinforced with fumed silica, silica (Nanopox F700), and rubber (Albipox 1000) are subjected to uniaxial tensile deformation combined with periodic boundary conditions. The local and nonlocal stress fields are computed through numerical simulations and after post-processing are compared with each other. The results acquired through the nonlocal theory exhibit a softening effect, resulting in reduced stress concentration and less of a discontinuous behaviour. This research contributes to the literature by proposing an efficient and standardised numerical method for analysing the small-scale stress distribution in small-scale multi-phase materials, providing a method for more accurate design in the nano-scale regime. This proposed method is also easy to implement in standard finite element software that employs classical continuum theory.

Antioxidant Capacity of Thyme (Thymus vulgaris) Essential Oil and Its Effect on In Vivo Fertility of Rams Subjected to Testicle Heat Stress.

The detrimental effects of hyperthermia on the testes and the protective effect of thyme essential oil against testicular damage induced by this stress in rams were studied. Twenty-four rams of the Barbarine breed with an average weight of 62.5 ± 0.3 kg and an average age of 24 ± 0.6 months. The experiment consisted of inducing localized heat stress on the first group of rams by applying heat bags to both testicles of six rams (G s). The second group underwent the same heat stress on the testes but received orally 100 µL/day/animal of thyme essential oil (G s-he). A positive control did not undergo stress but received thyme essential oil (G he) with the same doses as the (G s-he) group, and the negative control did not undergo either stress or receive the essential oil of thyme (G c). One hundred twenty-eight adult ewes of the same breed divided into four groups of 32 ewes were used to study the effect of different treatments on the in vivo ram's fertility. Ewes are synchronized and we have applied natural mating with oestrus control, the reproduction balance sheet is calculated after lambing. The results showed that tests of heat stress (HS) negatively affect semen quality but did not cause infertility. However, neither tests for heat stress nor treatment with thyme EO significantly affected the haematological profile. The study of the effect of heat stress on the testes on fertility in vivo showed a drop in the number of females who were fertilized at the first oestrus and consequently a drop in fertility. However, the rams that suffered the same stress but were treated with EO thymus recorded an improvement in these parameters.

A Transition State Theory-Based Continuum Plasticity Model Accounting for the Local Stress Fluctuation

Based on the transition state theory, a continuum plasticity theory is developed for metallic materials. Moreover, the nature of local stress fluctuation within a material point is considered by incorporating the probability distribution of the stresses. The model is applied to investigate the mechanical behaviors of 316 L stainless steel under various loading cases. The simulated results closely match the results obtained by the polycrystal plasticity model and experiments. The mechanical behaviors associated with strain rate sensitivity, temperature dependence, stress relaxation, and strain creep are correctly captured by the model. Furthermore, the proposed model successfully characterizes the Bauschinger effect, which is challenging to capture with a conventional continuum model without additional assumptions. The proposed model could be further employed in the design, manufacturing, and service of engineering components.

Constructing Targeted Strong Nb4d-O2p-Li2s Configurations to Obtain Excellent Energy Density and Long Life for Li-Rich Cathodes.

The Li-rich Mn-based cathode materials (LMRs) deliver excellent energy density and exhibit low cost, which are considered as the most promising cathode materials for the next generation lithium-ion batteries. However, the irreversible redox reaction of the oxygen atoms directly leads to release oxygen and intensifies phase transformation. Besides, the local stress and strain will be generated due to the unit-cell volume difference between R-3m and C2/m phases, which continuously aggravates the collapse of secondary particles. Herein, the strong Nb4d-O2p-Li2s configurations at the Li1 sites of the TM-layer in the C2/m phase and secondary particles with the radial arrangement of refined primary particles are designed to inhibit oxygen release and relieve lattice stress by Nb2O5 treatment. Meanwhile, the preferential growth of the active {010} planes is presented to obtain an excellent transmission rate of Li+. As a result, the designed LMR delivers remarkable electrochemical properties with high discharge capacity and initial coulomb efficiency of 276 mAh g-1 and 85 % at 0.1 C, outstanding cycling retention rate of 81 % after 300 cycles. This novel crystal structure combining oxygen coordination regulation and micro-nano scale design provides inspiration for the design of high-performance LMRs.

Constructing Targeted Strong Nb4d−O2p−Li2s Configurations to Obtain Excellent Energy Density and Long Life for Li‐Rich Cathodes

AbstractThe Li‐rich Mn‐based cathode materials (LMRs) deliver excellent energy density and exhibit low cost, which are considered as the most promising cathode materials for the next generation lithium‐ion batteries. However, the irreversible redox reaction of the oxygen atoms directly leads to release oxygen and intensifies phase transformation. Besides, the local stress and strain will be generated due to the unit‐cell volume difference between R‐3m and C2/m phases, which continuously aggravates the collapse of secondary particles. Herein, the strong Nb4d−O2p−Li2s configurations at the Li1 sites of the TM‐layer in the C2/m phase and secondary particles with the radial arrangement of refined primary particles are designed to inhibit oxygen release and relieve lattice stress by Nb2O5 treatment. Meanwhile, the preferential growth of the active {010} planes is presented to obtain an excellent transmission rate of Li+. As a result, the designed LMR delivers remarkable electrochemical properties with high discharge capacity and initial coulomb efficiency of 276 mAh g−1 and 85 % at 0.1 C, outstanding cycling retention rate of 81 % after 300 cycles. This novel crystal structure combining oxygen coordination regulation and micro‐nano scale design provides inspiration for the design of high‐performance LMRs.

Synergistic effects in Na0.5Bi0.5TiO3-based thin film through stress field regulation for excellent capacitive energy storage

Thin film dielectric capacitors have attracted significant attention under the current trend of integration and portability in electronic devices. In this work, Na0.5Bi0.5(Fe0.03Ti0.97)O3–SrTiO3 (NBFT–STO) thin films are synthesized via sol–gel method onto flexible Pt/Mica and rigid Pt/Ti/SiO2/Si substrates, respectively to obtain NBFT–STO dielectric capacitors under different local stress fields. Synergistic effects between dielectric polarization and breakdown strength (EBD), as well as dielectric polarization and polarization hysteresis are obtained, with the rigid one exhibiting higher EBD and the flexible one possessing high polarization linearity. Excellent capacitive energy storage performance with Wrec of 28.00 J/cm3 and η of 70.44 % are obtained at 20 kHz for the NBFT–STO thin film onto Pt/Mica. These findings provide a new route to modulate polarization behavior of NBT–based thin film through stress field regulation for capacitive energy storage.

Beam Local Stress Prediction Model for Incremental Launching Construction Based on SSA-SVR Algorithm

In the multi-point incremental launching construction process, without setting temporary piers at the mid-span, it is difficult to ensure the synchronization of the launching equipment at the same pier, which can easily cause the beam to deviate from the design axis, leading to changes in the stress of the beam. Calculating the local maximum stress of the beam when lateral deviation occurs is beneficial for establishing a reasonable and reliable threshold for controlling beam deviations. To address this issue, this paper utilizes a finite element model of the bridge under typical adverse conditions, simulating the lateral deviation and asynchronous jacking of the beam to explore stress variation patterns. The results show that the beam stress increases as the lateral deviation and jacking differences increase, severely affecting the structural safety. To overcome the inefficiency of the finite element modeling method when dealing with multiple working conditions and to establish a reasonable deviation control threshold, this study proposes a beam local stress prediction model under the combined influence of lateral deviation and jacking height differences based on the SSA-SVR algorithm. The model calculates the local maximum stress of the beam for 2500 sets of parameters. An engineering case analysis shows that the prediction model has high calculation accuracy, reliable results, fast computational speed, and high efficiency. Based on the stress prediction results, it is recommended to set the jacking height difference control threshold at 20 mm. When the jacking height difference is less than 20 mm, the local maximum stress value under the combined influence of both parameters should be less than the standard limit. The corresponding lateral deviation control threshold can be dynamically adjusted according to the actual travel difference recorded by the jacking equipment, with the control precision improved to 1 mm.

Effects of smoking on local and systemic oxidative stress markers in individuals with periodontitis

Aim: This study aimed to assess the effects of smoking on systemic and local oxidative stress markers in patients with periodontitis. Methods: A total of 72 patients with periodontitis [38 smokers (S +P+), 34 non-smokers (S-P+)] and 54 periodontally healthy individuals [28 smokers (S+P-), 26 non-smokers (S-P-, control)] were included. After clinical measurements and samplings, the cotinine level, total antioxidant capacity (TAOC), total oxidative status (TOS), and malondialdehyde (MDA) level in the serum and saliva were determined, and the oxidative stress index (OSI) was calculated. Kruskal-Wallis and Mann-Whitney U tests were used for multiple and pairwise comparisons. Correlations were analyzed using Pearson correlation coefficient. P&lt;0.05 was considered statistically significant. Results: Smoking and periodontitis decreased the serum and salivary TAOCs and increased the TOS, MDA level, and OSI. The smokers with periodontitis had the lowest TAOC and the highest TOS, MDA level, and OSI, while the controls had the highest TAOC and the lowest TOS, MDA level, and OSI. The systemic and local effects of smoking seemed more pronounced than those of periodontitis in the oxidative stress study, but no significant difference was identified between the smoking (S+P-) and periodontitis (S-P+) groups. The clinical parameters and oxidative stress markers showed both substantial positive and negative relationships in all groups (p&lt;0.01). Conclusions: It can be concluded that smoking and periodontitis (S+P+) are associated with a decrease in serum and salivary TAOCs and an increase in TOS, MDA levels, and OSI. Smoking has a similar effect as periodontitis on local and systemic oxidative stress, and oxidative stress caused by smoking may be a significant factor in the pathophysiology of periodontitis.

High‐temperature behavior and self‐enhancing mechanisms of oxide‐bonded SiC porous ceramics

AbstractOxide‐bonded SiC porous ceramics (SCPCs), synthesized via reaction bonding, exhibit significant potential for high‐temperature applications. However, incorporating sintering aids inevitably results in a considerable quantity of amorphous glass phase within SCPCs, thereby introducing risks to their high‐temperature mechanical performance. In this study, we employ in‐situ characterization techniques to investigate the high‐temperature behavior of SCPCs. Our findings reveal that SCPCs demonstrate remarkable high‐temperature self‐enhancing properties, with a critical bending strength at 800°C. Beyond this temperature, the strength declines sharply. Intriguingly, the critical bending strength is 36.6% greater than at ambient temperature. Moreover, elevated temperatures enhance the elastic modulus and promote the transition of SCPCs from multilinear to nonelastic fracture. The neck phase, which imparts strength to the SCPCs, is composed of four distinct layers along the depth direction: silicate glass, oxygen‐containing, silicon‐rich, and SiC region, as revealed by FIB‐TEM. The transformation from α to β‐cristobalite in the oxygen‐containing region improves the thermal expansion match with SiC, thereby mitigating local stress concentration. Furthermore, the compressive stress within the neck region intensifies with increasing temperatures, thereby inhibiting crack propagation. This work provides a basis for the high‐temperature applications of SCPCs.

Displacement-potential analysis of ply-stresses in a partially guided non-uniform short-column of hybrid laminated composites

Reliable and accurate analysis of local stresses in structural problems of fiber-reinforced laminated composites involving nonuniform geometry is of utmost practical importance, especially when they are subjected to local loads and supports. In this research, a new study of ply stresses in a partially guided, nonuniform, short composite column of hybrid laminates, subjected to an eccentrically distributed loading is conducted using an efficient computational scheme. The analytical modeling of the present mixed-boundary-value problem of laminated structure is realized in terms of a single scalar function of space variables (called as displacement-potential function), which is defined by the displacement components of plane elasticity, and is governed by a single fourth-order partial-differential equation of equilibrium. In this modeling approach, the original three-dimensional symmetric laminated column is reduced to a plane-stress scalar-field problem of an equivalent imaginary lamina in an attempt to obtain the corresponding strain field (global laminate strain), which is then used to determine the stress fields of individual plies through the respective transformed reduced stiffness matrices. A finite-difference based computational scheme is developed to solve the representative nonuniform equivalent lamina in terms of the displacement-potential function, which is however well capable of dealing with different ply materials as well as fiber orientations, together with the associated mixed and changeable physical conditions along the boundaries of the column. A 28-ply balanced hybrid laminate composed of boron-epoxy and glass-epoxy plies with various fiber orientation is considered as the structural material for the present column. The stress fields obtained for individual plies as well as the overall laminate are analyzed in the perspective of a number of practical issues of structural design, which include material hybridization, eccentricity of loading and attachment of partial guides to the column. The design stresses of the nonuniform laminated column are identified to be affected significantly by the material and orientation of fibers as well as the laminate hybridization. An attempt is also made to verify the soundness and accuracy of the present computational scheme through the comparison of the present potential-function solutions with those obtained by the conventional computational method.

Suppression anti-vibration of ultra-small diameter neutron generators for logging while drilling via potting materials

To enhance the reliability of the logging-while-drilling (LWD) neutron generator in harsh environments, this paper proposes a novel polymer monolithic potting protection scheme that can effectively decrease response of the structure under vibrational excitation by selecting suitable polymer potting material and installation method. This paper systematically evaluates the influence of viscoelastic parameters of the polymer potting material on vibration energy dissipation through theoretical calculations. Additionally, it thoroughly investigates the influence of the coupling between the potting modulus and the installation method on the reliability of the structure through finite element analysis. The results demonstrate that potting material with a shorter high-frequency relaxation time can more effectively absorb vibration energy. As the potting modulus increases, the maximum stress of the neutron tube decreases by 96.4%, 93.7%, and 84.7% under short-span, medium-span, and long-span installation methods, respectively. The maximum strain also decreases by 96.6%, 93.9%, and 86.5% respectively. By using the short-span support and high modulus potting material, the local stress and strain can be minimized. A prototype vibration test verifies the effectiveness of this method in improving the reliability of the neutron generator. This analysis provides a reference and reliability prediction for the design of future LWD neutron generators.

Effective Bulk Rheology of a Two‐Phase Subduction Shear Zone: Insights From Micromechanics‐Based Modeling and Implications for Subduction Interface Slow Slip Events

AbstractSubduction interfaces exhibit various slip styles, including slow slip events (SSEs). We use a micromechanics‐based approach to calculate the effective rheology of a shear zone containing ellipsoidal amphibolite clasts deforming by dislocation creep within an interconnected linear‐viscous phyllosilicate‐dominated matrix. Frictional failure occurs if local stress exceeds Mohr‐Coulomb yield strength. At moderate fluid overpressure, mixed‐frictional‐viscous behavior emerges at 350–560C, consistent with a broad zone of mixed fault slip behavior without requiring extreme fluid overpressures. Increasing stress in this transition zone promotes local frictional failure and raises bulk strain rate. If, however, the bulk strain rate increases by more than one order of magnitude, system‐wide frictional sliding becomes preferable. This strain rate increase is insufficient to explain the slip rates observed in geophysically detectable SSEs. Therefore, viscous matrix flow as modeled here cannot explain SSEs without either invoking dynamic weakening within a frictional‐viscous flow or a mechanism switch to dominantly frictional sliding.

Modified Centroid of Root Projection Method for Determining the Center of Resistance of a Tooth

Abstract Center of resistance (CR) has been widely accepted in dentistry as a reference point for controlling tooth moment, which depends on the direction of loading and the morphology of the periodontal ligament (PDL). In clinical practice, dentists estimate the location of CR based on the morphology of the root of teeth, which may lead to a misestimation of orthodontic treatment. A quick method was proposed to efficiently determine the CR by identifying the centroid of the root projection (CRP), according to the orthodontic force. However, the original CRP method was limited to single-rooted teeth and it did not provide a strategy for handling the overlapping roots projection of multi-rooted teeth. To address this issue, we expanded the CRP method to accommodate multi-rooted teeth by applying the weighted average method. We further validated the modified CRP method using finite element simulation (FEA) for both single-rooted and multi-rooted teeth considering mesial-distal and buccal-lingual force directions. The evaluation of displacement distribution along the projection direction allowed us to assess translation and rotation movements, which confirmed that the centroid of root projection can accurately serve as the CR for the multi-rooted teeth. Additionally, we observed heterogeneous stress distributions in the multi-rooted teeth. Considering the well-acknowledged bone remodeling effect in response to local stress states, this indicated that the comprehensive indexes beyond the CR are desired for evaluating or controlling the tooth movement.

Dynamics of RNA localization to nuclear speckles are connected to splicing efficiency.

Nuclear speckles are nuclear membraneless organelles in higher eukaryotic cells playing a vital role in gene expression. Using an in situ reverse transcription-based sequencing method, we study nuclear speckle-associated human transcripts. Our data indicate the existence of three gene groups whose transcripts demonstrate different speckle localization properties: stably enriched in nuclear speckles, transiently enriched in speckles at the pre-messenger RNA stage, and not enriched. We find that stably enriched transcripts contain inefficiently excised introns and that disruption of nuclear speckles specifically affects splicing of speckle-enriched transcripts. We further reveal RNA sequence features contributing to transcript speckle localization, indicating a tight interplay between transcript speckle enrichment, genome organization, and splicing efficiency. Collectively, our data highlight a role of nuclear speckles in both co- and posttranscriptional splicing regulation. Last, we show that genes with stably enriched transcripts are over-represented among genes with heat shock-up-regulated intron retention, hinting at a connection between speckle localization and cellular stress response.

Simulation analysis of force and fatigue life of circular wheel of crawler vehicle

During loading and driving, the wheels bear the vertical load from the body mass and the excitation load generated by uneven road surface on the one hand, and bear the driving torque on the other hand. The load-bearing methods of wheels are generally divided into bottom load-bearing and top load-bearing. This paper describes the structural characteristics of the track system of the articulated track vehicle and the interaction relationship between the main components of the track system. Finite element calculation is carried out based on ANSYS software to obtain the stress distribution of each key component under various loading methods. It can be seen from the results that all key components of the track system can meet the strength and rigidity requirements; although there are also areas with large local stress, they are all within the safe range, which is mainly caused by stress concentration. Safe life is obtained through fatigue analysis.

Influence of ultrasonic assistance on the microstructure and friction properties of laser cladded Ni60/WC composite coatings

The effects of different ultrasonic vibration powers on the distribution, phase structure, friction and wear properties of WC reinforced particles in laser melted Ni60/WC composite coatings are investigated. The effects of ultrasonic vibration on the microstructure, elemental distribution, crystal orientation, friction and wear properties of the fused coatings are analyzed. The experimental results show that the deposition of WC particles in the lower and middle parts of the coating is significantly improved after the introduction of ultrasonic vibration during the fusion cladding process. In particular, at 600 W ultrasonic power, not only the distribution uniformity of tungsten carbide particles in the coating is optimal, but also the composite coating shows better wear resistance. However, too much ultrasonic power increases the possibility of particle agglomeration. In addition, although the phase pattern of the coating does not change after ultrasonic vibration, the width of the columnar crystalline region of the coating is reduced, and the coating is covered by a homogeneous lamellar nanoscale eutectic structure with the phase compositions of the γ-(Fe, Ni) and M23C6 phases. The ultrasonic vibration improves elemental segregation of the coating, reduces the large number of precipitated phases in the coating, weakens the grain growth orientation, and relieves the local stress concentration in the coating. In addition, the mechanism of the influence of WC particles on the microstructure evolution and wear resistance of the composite coatings is discussed.