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Measurement of coating–substrate interface stiffness can indirectly characterize interface bonding quality. This paper proposes a noval quantitative inversion coating–substrate interface stiffness method based on the multi-resonance frequencies of a constructed ultrasonic echo phase derivative spectrum (UEPDS). The theoretical relationship between UEPDS resonance frequencies and interface stiffness is derived. The detection frequency and high-sensitivity interface stiffness range are optimized based on the sensitivity analyzed. Numerical simulation and experiment are implemented on a 0.48 mm aluminum layer/carbon steel substrate specimen to prove the validity of the proposed ultrasonic method. The simulation results show that the maximal relative error between the inversion and the preset interface stiffnesses is reduced from 23% to 8% compared with the traditional ultrasonic reflection coefficient amplitude spectrum-based (URCAS-based) method. The experiment results indicate that the UEPDS-based inversion interface stiffnesses have the same trend as the nominal contact pressures between the coating–substrate interface. [ABSTRACT FROM AUTHOR]

Nonwovens have wide application areas due to their advantageous properties like low cost, high production efficiency, and tuneable properties. They are mostly used for disposable products. Combining bicomponent fiber spinning with hydroentanglement method is one of the innovative methods to obtain nonwovens for durable applications. On the other hand, ultrasonic welding is an alternative assembling method for disposable products made of low weight nonwovens. In this study, the ultrasonic weldability of relatively heavier weight and thicker nonwoven fabrics made of polyester: polyamide bicomponent microfilaments were examined in order to combine the advantages of nonwovens and ultrasonic welding. Relatively higher thickness and weight, and also fiber composition of the nonwoven fabrics were compelling effects of the study that drove the motivation. Overall 60 samples were produced using five nonwoven fabrics with varying unit masses and 12 selected ultrasonic welding types. Seam strength and strain assessments were supported with stereomicroscope and visual inspections in evaluating the welds. Results showed that despite having thick seam lines up to 1.6 mm, successful welded seams could be obtained. Depending on the welding parameters, seam lines of some samples exhibited waviness, color changes, and deformations but these situations did not drastically affect the seam strength of samples. [ABSTRACT FROM AUTHOR]

The wire to terminal joints are prepared using ultrasonic welding and find extensive application in various fields, such as new energy vehicles and aerospace. Traditionally, tensile strength tests have been employed for welding quality inspection. However, this study proposes an automatic nondestructive evaluation scheme to overcome the inefficiency and destructiveness associated with tensile testing. To achieve this, a 5 MHz/32-element array ultrasound probe is utilized for ultrasound detection and signal acquisition from two groups of joints categorized as OK (good quality) and NG (poor quality) based on their welding quality. Signal processing techniques including short-time Fourier transform, wavelet transform, and Gramian angular field are applied to convert one-dimensional time series into two-dimensional signal feature maps. Convolutional neural networks such as VGGNet, ResNet, DenseNet, and MobileNet are utilized for the classification of two-dimensional signal feature maps. The comprehensive evaluation of different feature maps and combinations of neural networks is conducted from various perspectives including network complexity, recognition accuracy, memory consumption, and inference time. The study findings indicate that wavelet transform feature maps achieve the highest accuracy across diverse neural networks, reaching up to 95% accuracy in VGGnet13 despite higher associated costs. In MobileNet-Small and ShuffleNet-V2 networks, the accuracy stands at approximately 85%, accompanied by faster inference times and lower costs. Considering all factors holistically, the combination of wavelet transforms feature maps with MobileNet and ShuffleNet demonstrates superior cost-effectiveness and suitability for ultimate deployment and application on mobile devices facilitating automated non-destructive assessment of wire to terminal joints quality. [ABSTRACT FROM AUTHOR]

Piezocatalysis presents an innovative catalytic technique that utilizes the piezoelectric properties of catalysts to convert mechanical energy into electrical energy, thereby driving chemical processes. While various methods for driving piezocatalytic reactions have been developed, there is a notable absence of comprehensive research on piezocatalytic performance across multiple methods. In this context, this study explores the potential of (1- x)Pb(Ni 1/3 Nb 2/3)O 3 - x PbTiO 3 (PNN-PT) based catalysts as efficient piezocatalysts using both ultrasonic vibration and ball milling. The optimal reaction rate constants of the PNN-PT piezocatalyst under ultrasonic vibration and ball milling are found to be 0.0775 min−1 and 0.0265 min−1, respectively. Notably, PNN-PT-based catalysts exhibit outstanding catalytic activity up to ultra-high substrate concentrations (65 mg/L), suggesting possible industrial applications. The exploration of the reaction mechanism indicates that •OH is the main reactive radical, the catalytic reaction activity demonstrates a direct relationship with •OH quenching, and the high •OH generation rate of PNN-PT further illustrated their suitability as environmental purification catalysts. [ABSTRACT FROM AUTHOR]

Ultrasonic welding is a subset of frictional solid-state joining processes. This process, with its ability to join thin and dissimilar metallic materials, has been noticed by researchers. On the other hand, the dissimilar joining of aluminum and copper wires and electrodes in the battery of electric cars and hybrid electric cars to reduce the cost and weight of the car structure has been raised as one of the important industrial challenges. Therefore, in this research, ultrasonic welding of dissimilar joining of Al 1050 sheet with a thickness of 0.2 mm and copper wire with a cross-sectional area of 2.5 mm2 was studied. For this purpose, the experiment was designed based on the response surface methodology (RSM) and Box-Behnken design (BBD). Static pressure, welding time, and vibration amplitude were selected as input variables in three levels. Then, the tensile test was performed on the specimens to evaluate the shear strength of the welded joint. The results of ANOVA showed that the linear and second-order effects of static pressure and vibration amplitude have the greatest effect on the shear force. Also, the regression model of shear force was extracted as a function of linear, interactive, and quadratic terms from the input variables. Finally, the optimal combination of input variables to achieve the maximum shear force was determined with a desirability of 0.935, and by performing the verification test, the competence of the regression model to predict the shear force was confirmed. [ABSTRACT FROM AUTHOR]

In this article, ultrasonic welding of glass fiber-reinforced thermosetting polymers which were surface-treated by laser engraving, is investigated. Composite samples were prepared by hand lay-up method. In the next step, surface treatment of the composite samples was performed by means of a high-power laser confirming two grooved and circular patterns. Polymethylmethacrylate and polypropylene as the amorphous and semicrystalline thermoplastic intermediate layers were incorporated to create a joining between the two thermoset parts. Besides, the welding time was considered in the three different levels. In order to investigate the microstructure of the welding zone, scanning electron microscopy analysis were accomplished. Besides, lap-shear tests were performed so as to evaluate the mechanical performances of the welded parts. Morphological studies indicated that in the surface-treated samples, the penetration of the intermediate material into the welded parts is much higher than neat samples and this leads to the superior interaction between the coupling layer and the surface-treated parts. Confirming the morphological outcomes, the results of the lap-shear tests specified that the application of surface treatment using laser engraving has increased the laps-shear strength almost 5.5 times compared to the samples without preparation. [ABSTRACT FROM AUTHOR]

This study investigated the role of interfacial deformability in bond integrity and strength, particularly in the production of robust joints between harder austenitic stainless steels (SS) during ultrasonic welding. The specimen without the interlayer experienced limited strength enhancement owing to internal cracking from continuous sliding at interfacial temperatures below 0.6 times the melting point (Tm), which is attributed to the limited deformability of the austenitic SS. In contrast, introducing Fe and Ni interlayers between the substrates resulted in a notable increase in the interfacial strength, surpassing 2500 N in the peak load within a reduced welding duration. The correlation between the interfacial strength and the peak temperature suggests that a substantial decrease in hardness below 0.4 Tm is sufficient for extensive bond formation. Moreover, dynamic recrystallization (DRX) led to grain refinement in the Fe interlayer owing to shorter weld durations, whereas grain growth was observed in the Ni interlayer due to higher peak temperatures. Both the Fe and Ni interlayers significantly improved the bonding integrity by accommodating plasticity through the above phenomena without severe damage to the substrates, leading to increase of interfacial strength by 24% (2050 N to 2500 N) and reduction of weld duration by 40% (1.5 s in Fe interlayer). In addition, the fracture position after the lap shear test shifted from the edge of the weld area to the SS substrate. [ABSTRACT FROM AUTHOR]

Ultrasonic welding (USW) of thermoplastics plays a significant role in the automobile industry. In this study, the effect of the welding time on the joint strength of ultrasonically welded acrylonitrile–butadiene–styrene (ABS) and the weld formation mechanism were investigated. The results showed that the peak load firstly increased to a maximum value of 3.4 kN and then dropped with further extension of the welding time, whereas the weld area increased continuously until reaching a plateau. The optimal welding variables for the USW of ABS were a welding time of 1.3 s with a welding pressure of 0.13 MPa. Interfacial failure and workpiece breakage were the main failure modes of the joints. The application of real-time horn displacement into a finite element model could improve the simulation accuracy of weld formation. The simulated results were close to the experimental results, and the welding process of the USW of ABS made with a 1.7 s welding time can be divided into five phases based on the amplitude and horn displacement change: weld initiation (Phase I), horn retraction (Phase II), melt-and-flow equilibrium (Phase III), horn indentation and squeeze out (Phase IV) and weld solidification (Phase V). Obvious pores emerged during Phase IV, owing to the thermal decomposition of the ABS. This study yielded a fundamental understanding of the USW of ABS and provides a theoretical basis and technological support for further application and promotion of other ultrasonically welded thermoplastic composites. [ABSTRACT FROM AUTHOR]

In order to enhance the performance of magnesium alloy and galvanized steel welds, ultrasonic vibration was applied to the laser welding process, and the effect of ultrasonic on mechanical properties was verified through experimental methods. The laser welding system for the lap weld seam was designed, and the ultrasonic vibration module and image detection module were added, which can obtain the influence of ultrasonic vibration on the molten pool area. Under the conditions of ultrasonic vibration power of 1000 W and 0 W, the characteristics of the weld pool area, metallographic structure, tensile strength, fracture morphology, hardness, residual stress, wear resistance, and corrosion resistance of the weld specimen were compared. The image data acquisition structure indicated that ultrasonic vibration can effectively reduce the ineffective area of the molten pool and make the energy in the molten pool more concentrated. Under the influence of ultrasonic vibration, the maximum molten pool area decreased to 5.38 mm2, with a variation range of 3.9 %, and the proportion of pores was greatly reduced. Research found that ultrasonic vibration can significantly improve the microstructure characteristics of the fusion welding zone, with an average grain size reduced to 23 μm. The reduction of grain size and refinement of microstructure were beneficial to the improvement of mechanical properties of magnesium alloy joints, with a yield strength increase of 6.5 %. Ultrasonic vibration had little effect on the hardness of the heat affected zone, it can increase the average hardness of the weld zone by more than 5 % and reduce the maximum residual stress by more than 50 %. Under different pressure and friction speed conditions, the maximum wear amount can be reduced by more than 25 %. At the same time, the resistance to oxidation corrosion and electrochemical corrosion also can be improved to a certain extent. [ABSTRACT FROM AUTHOR]

In ultrasonic metal welding, low specific resistances and large joining surface cross-sections require the use of mechanical testing to quantify the joint quality. In this study, different quality features of ultrasonically welded joints made of pure copper sheet are investigated during the successive phases of joint formation. Two test series with different workpiece geometries are examined. It is shown that mechanical quality features such as shear and peel forces behave differently over the formation of the joint and are not transferable. As an alternative to these, laser scanning microscopy is used to record images of the fracture surface that describe the growth of the joint area during formation. The study finds that shear tensile force growth and joint area growth are non-linear and comparable, with optimized welds achieving joint areas of 30 mm2 out of 64 mm2 and 6 mm2 out of 16 mm2. Although overall quality increases with increasing welding time, the material strength in the joint zone decreases. Depending on the original rolling condition, between 43% and 59% of the original material strength can be identified as the joint strength. The automatic analysis of fracture images is a suitable alternative to mechanical testing for similar joints. [ABSTRACT FROM AUTHOR]

Although phased array ultrasonic testing (PAUT) technology has been widely employed in pipeline weld defect recognition, current defect recognition still relies on manual operation, which limits its efficiency. By combining deep learning with PAUT, this paper presents a new neural architecture based on YOLOv5 called DFW-YOLO that can call defect indications automatically. To address redundant defect feature maps, the FasterNet backbone is introduced to enhance the model’s feature extraction ability. Additionally, partial dilated convolution (PDConv) and partial convolution (PConv) with an atrous convolution branch are designed to extend the receptive field of the backbone network, mitigating the chance of feature loss. Furthermore, a weighted generalised feature pyramid network (WGFPN) structure is proposed as the neck network. This structure combines the reparameterized generalised feature pyramid network (RepGFPN) with the weighted aggregated concatenation (WAC) structure and eliminates inefficient branches to enhance the model’s feature fusion ability. The experimental results demonstrated that DFW-YOLO outperforms the original YOLOv5 in terms of detection performance. The precision, recall, mean average precision (mAP)@0.5, and mAP@0.5:0.95 are indicators for DFW-YOLO and reach 97.4%, 97.5%, 98.3%, and 68.2%, respectively, marking 4.8%, 5%, 2.7%, and 22.5% improvement compared to the original YOLOv5. [ABSTRACT FROM AUTHOR]

Highlights Carbon fiber reinforced polyamide 66 (CF/PA66) sheets are ultrasonically welded by applying nylon meshes as energy directors (EDs) in this paper. The influence of mesh dimensions is revealed by observing the joint formation process, joint mechanical performance, joint cross‐sectional morphology and joint failure mode. Results show that the joint formation process can be divided into wire flattening stage, ED spread stage, tight bonding stage, and mixing stage. The nylon mesh ED with moderate wire spacing, small wire diameter and small mesh area promotes better weld quality. Welding energy will be dispersed rather than concentrated if the mesh area is too large, resulting in reduced failure load. The joints exhibit two fracture modes: interfacial fracture (IF) and workpiece fracture (WF), and the fracture mode of the joints with nylon mesh EDs transits from IF to WF as the welding energy increases. Five types of nylon mesh are used as energy directors to join CF/PA66 sheets by ultrasonic welding. The influence of nylon mesh dimensions on the mechanical property and fracture mode of joints is investigated. The formation process of ultrasonically welded joints can be separated into wires flattening stage, ED spread stage, tight bonding stage, and mixing stage. [ABSTRACT FROM AUTHOR]

ABS is a popular material for structural applications in automotive sector because of its low cost, high apparent shine and finishing, ease of property improvement, simplicity in forming complicated shapes while preserving strength, and durability. It is preferred to be joined using ultrasonic welding (USW) process. So, in this study, the ultrasonic welding (USW) parameters specifically welding time, amplitude, axial pressure and holding time were optimized for enhancing the tensile shear fracture load (TSFL) bearing capability of acrylonitrile butadiene styrene (ABS) plastic lap joints for automotive applications. The computational and stastical approach of response surface methodology (RSM) was used for formulating the parametric empirical relationship (PER) and optimize the USW parameters. The PER was validated using analysis of variance. The response surfaces were created using RSM and analyzed. From the results, it was observed that the ABS joints created using the welding amplitude of 80%, welding time of 2.0 s, axial pressure of 2 bar, and holding time of 5.0 s exhibited greater tensile shear fracture load (TSFL) bearing capability of 1.30 kN. The PER accurately predicted the TSFL of ABS joints within 1% error on 95% confidence. [ABSTRACT FROM AUTHOR]

Abstract This study investigated the role of interfacial deformability in bond integrity and strength, particularly in the production of robust joints between harder austenitic stainless steels (SS) during ultrasonic welding. The specimen without the interlayer experienced limited strength enhancement owing to internal cracking from continuous sliding at interfacial temperatures below 0.6 times the melting point (Tm), which is attributed to the limited deformability of the austenitic SS. In contrast, introducing Fe and Ni interlayers between the substrates resulted in a notable increase in the interfacial strength, surpassing 2500 N in the peak load within a reduced welding duration. The correlation between the interfacial strength and the peak temperature suggests that a substantial decrease in hardness below 0.4 Tm is sufficient for extensive bond formation. Moreover, dynamic recrystallization (DRX) led to grain refinement in the Fe interlayer owing to shorter weld durations, whereas grain growth was observed in the Ni interlayer due to higher peak temperatures. Both the Fe and Ni interlayers significantly improved the bonding integrity by accommodating plasticity through the above phenomena without severe damage to the substrates, leading to increase of interfacial strength by 24% (2050 N to 2500 N) and reduction of weld duration by 40% (1.5 s in Fe interlayer). In addition, the fracture position after the lap shear test shifted from the edge of the weld area to the SS substrate.

The rapid and solid joining of thermoplastic to metal is of great significance for structural lightweighting. A thermoplastic acrylonitrile butadiene styrene (ABS) and laser textured 5052 Al is joined by ultrasonic welding with longitude wave in this study. Influence of the texturing type on microstructure and joint strength are investigated. Experimental results showed that the texturing type was a major factor in joint strength, and the mesh array was superior than circular hole array in terms of joint strength. The maximum joint strength of 17.87 MPa was obtained in L1, which was about 2.4 times and 3.6 times of these other two cases. Interfacial and cohesive failure mode was observed, and the fracture surface can be divided into four different parts: light black mark Region Ⅰ, transitional Region Ⅱ, Region Ⅲ with dense residues, and porous structure Region Ⅳ. The joint strength increased with the increase of Regions Ⅱ and Ⅲ while dropped with the occurrence of Region Ⅳ. Thermal decomposition of ABS composite resulted from the high temperature during welding process was responsible for the formation of Region Ⅳ. The joining mechanism in UW of ABS to laser textured 5052 Al was mechanical interlocking. Successful joining of ABS/Al hybrid structure by ultrasonic welding appears to be a reliable and potential technique for industrial applications.

In this study, ultrasonic welding (USW) of lap joints of polyetherimide (PEI) plates (adherends) with carbon fiber (CF) prepregs impregnated with PEI was investigated. No energy director (ED) was used, so binder contents were varied in the prepregs to compensate for the lack of the polymer in the fusion zone. In addition, the effect of the USW parameters on the structure and the mechanical properties of the lap-joints were analyzed. The most homogeneous macrostructure, the maintained structural integrity of both the CF-fabric in the prepregs and the lap-joined PEI adherends, as well as the maximum strength properties (tensile strength) were revealed for the USW joints with the minimum polymer content in the prepreg. In this case, rising the USW time from 400 up to 800 ms radically changed the macrostructure of the fusion zone, while the strength properties did not vary significantly (shear stresses were 42�48 MPa). Computer simulation of the influence of the PEI/CF-fabric ratios in the prepregs on the deformation response of the USW joints showed that the prepreg thicknesses and, accordingly, the PEI/CF ratios did not exert a noticeable effect on the strain�stress (tensile) diagrams, while the determining factor was the adhesion level

Ultrasonic frequency pulse assisted TIG welding (UFP-TIG) experiments were conducted to join Inconel 690 alloy (IN690) by adding Inconel 718 alloy (IN718) as the filler. The effect of the filler on the microstructure, mechanical properties, and ductility dip cracking (DDC) susceptibility of IN690 joints were investigated. The results show that a variety of precipitates, including MC-type carbide and Laves phases, are formed in the weld zone (WZ), which are uniformly dispersed in the interdendritic region and grain boundaries (GBs). The increase in the thickness of the IN718 filler facilitates the precipitation and growth of Laves phases and MC carbides. However, the formation of Laves phases in the WZ exhibits a lower bonding force with the matrix and deteriorates the tensile strength of IN690 joints. Due to the moderate content of Laves phases in the WZ, the IN690 joint with 1.0 mm filler reaches the maximum tensile strength (627 MPa), which is about 96.5% of that of the base metal (BM). The joint with 1.0 mm filler also achieves the highest elongation (35.4%). In addition, the strain-to-fracture tests indicate that the total length of cracks in the joint with the IN718 filler decreases by 66.49% under a 3.8% strain. As a result, the addition of the IN718 filler significantly improves the mechanical properties and DDC resistance of IN690 joints. [ABSTRACT FROM AUTHOR]

The implementation of artificial intelligence (AI) techniques in industrial applications, especially solid-state welding (SSW), has transformed modeling, optimization, forecasting, and controlling sophisticated systems. SSW is a better method for joining due to the least melting of material thus maintaining Nugget region integrity. This study investigates thoroughly how AI-based predictions have impacted SSW by looking at methods like Artificial Neural Networks (ANN), Fuzzy Logic (FL), Machine Learning (ML), Meta-Heuristic Algorithms, and Hybrid Methods (HM) as applied to Friction Stir Welding (FSW), Ultrasonic Welding (UW), and Diffusion Bonding (DB). Studies on Diffusion Bonding reveal that ANN and Generic Algorithms can predict outcomes with an accuracy range of 85 – 99%, while Response Surface Methodology such as Optimization Strategy can achieve up to 95 percent confidence levels in improving bonding strength and optimizing process parameters. Using ANNs for FSW gives an average percentage error of about 95%, but using metaheuristics refined it at an incrementally improved accuracy rate of about 2%. In UW, ANN, Hybrid ANN, and ML models predict output parameters with accuracy levels ranging from 85 to 96%. Integrating AI techniques with optimization algorithms, for instance, GA and Particle Swarm Optimization (PSO) significantly improves accuracy, enhancing parameter prediction and optimizing UW processes. ANN's high accuracy of nearly 95% compared to other techniques like FL and ML in predicting welding parameters. HM exhibits superior precision, showcasing their potential to enhance weld quality, minimize trial welds, and reduce costs and time. Various emerging hybrid methods offer better prediction accuracy. [ABSTRACT FROM AUTHOR]

Bond strength between composite plates has often been evaluated using single-lap shear tests, with the difficulty of having the characteristics of the entire bond area reflected in the results. To overcome this limitation, a short-beam shear test was performed in this study. The specimens were fabricated by ultrasonic welding using carbon fiber reinforced polyether ether ketone laminates as the adherend and a resin mesh. The effect on mechanical characterization was investigated by varying the thickness and stacking configuration of the adherend and the welding energy. The highest apparent interlaminar shear strength was observed when an approximately 3 mm thick adherend of the quasi-isotropic laminate was welded, and the strength was approximately 17% lower than that of non-welded laminates. [ABSTRACT FROM AUTHOR]

This study evaluates the enhancement of laser welding using ultrasonic waves aimed at reorganising the intermetallic position in such a fashion that leads to increased mechanical properties of welds in battery pack assemblies for electric vehicles. The experiment employed 20 kHz and 40 kHz High-Power Ultrasound Transducers (HPUTs) in both contact and contactless modes. A simplified experimental configuration is suggested to represent conditions similar to those found in electric vehicle battery pack assemblies. Measurements of vibration transmission to aluminium alloy 1050 plates revealed more than a 1000-fold increase in acceleration amplitude in contact mode compared to contactless mode. The 20 kHz transducer in contactless mode demonstrated superior performance, showing a 10% increase in load and 27% increase in extension compared to welding without ultrasonic assistance. On the other hand, the 40 kHz transducer, while still improved over non-ultrasonic methods, showed less pronounced benefits. This suggests that lower-frequency ultrasonic assistance (20 kHz) is more effective in this specific context. The study explores ultrasonic assistance in laser welding copper (Cu101) to aluminium alloy 1050 using 20 kHz and 40 kHz HPUTs, showing that both transducers enhance microstructural integrity by reducing copper homogenisation into aluminium, with the 20 kHz frequency proving more effective in this context. A numerical simulation was conducted to evaluate the transmission of pressure into the molten pool of the weld, correlated with the vibration results obtained from the 20 kHz transducer. The numerical simulation confirms that no cavitation is initiated in the molten pool area, and all improvements are solely due to the ultrasonic waves. [ABSTRACT FROM AUTHOR]

This study investigates the impact of ultrasonic welding amplitudes and time on the properties of carbon fiber reinforced polyaryletherketone (CF/PAEK) composite joints. To enhance the performance of CF/PAEK ultrasonic welded joints, a hybrid energy director (ED) was proposed, which was composed of the interfacial microgroove and resin film or metal mesh. This study investigated the effect of different types of ED on the forming quality, shear failure load, and fracture interface microstructure of single lap joints made of CF/PAEK. The results indicated that the hybrid ED with resin film offers a distinct effect on enhancing the strength of ultrasonic welded joints. The hybrid ED with resin film essentially improves the tensile properties of the joint, with the strength and toughness increased by 35.8% and 174.3%, respectively. This strengthening effect is primarily attributed to the added resin film providing adequate interfacial resin. Sufficient resin is filled into the interior of the microgroove, ultimately forming a mechanical anchoring structure to strengthen the joint strength. [ABSTRACT FROM AUTHOR]

Fried seabass fish skin is one of the favorite snack products in Asian countries. This study was aimed to examine the influence of ultrasonic pretreatment and varying air-frying temperatures on the dehydration and thermodynamic characteristics of fried seabass fish skin product. Additionally, the research sought to assess mathematical models for understanding the kinetics of moisture transfer and moisture distribution within the fish skin during air-frying. Results showed that irrespective of frying temperatures, the moisture content and water activity (aw) of the air-fried fish skin decreased as the frying duration extended. The accuracy of the mathematical models was confirmed in portraying moisture transfer dynamics (proposed models), fat content (FC), activation energy, and Gibbs' energy during the air-frying process through regression analysis. As a result, Fikry's model has accurately described mass transfer in fish skin during air-frying process. Furthermore, the diffusion model effectively illuminated the spatial moisture distribution within the fish skin across diverse processing conditions. Applying ultrasonic pretreatment and elevated air-frying temperatures resulted in reduced FC, effective moisture diffusivity, and enthalpy, accompanied by an increase in the Gibbs energy difference. This knowledge holds the potential to inform the design and optimization of the frying process in the food industry. [ABSTRACT FROM AUTHOR]

The coil is used for electrical connection and energy conversion in the electromagnetic pulse welding (EMPW) process, so its structure affects the welding effect. In this work, for the dual H-shaped (DH) coil, the influence of the symmetry coefficient on the Cu-Al sheets EMPW was studied through the simulation and experiment. When the voltage was 7 kV and the symmetry coefficient g was 0.75, 1, and 1.33, the Vc-β trajectory curve contained by the simulation combined with the welding window curve (WWC) to analyze the dynamic process and welding effect. The relative impact speed was the fastest and the corresponding weld seam length was the longest when g was 1.33. The welding experiment results were consisted with the simulation results, it was beneficial to weld the Cu-Al sheets when g was 133. The symmetry coefficient could change the impact speed and angle to affect the welding effect. This work is of great significance for DH coil design. [ABSTRACT FROM AUTHOR]

Achieving carbon neutrality and alleviating the rural energy predicament are crucial aspects in rural areas, particularly in the severe cold regions of northeast China. Pellets serve as clean, renewable energy sources and are ideal alternative fuels. This study investigated the influencing factors and effects of mixed raw materials in ultrasonic vibration-assisted pelleting (UV-A pelleting). Rice straw and corn stover were mixed to produce pellets, and a central composite rotatable design (CCRD) was conducted to analyze the variables and their interactions on pellet density and durability. Mathematical regression models for pellet density and durability were established and then validated through ANOVA analysis. The results showed that all variables significantly affected the density and durability of pellets. The mixing ratio had a greater impact on pellet durability compared to density due to differences in ingredients. The optimal combination of process parameters included a mixing ratio of 25%, molding pressure of 4 MPa, pelleting time of 37 s, and ultrasonic power output at 200 W, resulting in a pellet density of 1301.18 kg/m3 with a durability reaching 94.26%. The desirability value (0.997) under these optimal conditions confirmed the validity of the models; further experiments also verified their effectiveness. The combustion of the optimized pellet was analyzed using thermogravimetric (TG) and derivative thermogravimetric (DTG) analysis in an air atmosphere. Four combustion stages and ignition temperature were provided. [ABSTRACT FROM AUTHOR]

Ultrasonic plastic welding is widely used in the bonding process of medical device accessories. In this paper, a thermo-force indirect coupling finite element analysis model was established in the ultrasonic plastic welding process between the blood cap and the shell of polypropylene (PP) dialyzer. The temperature field distribution between the blood cap and the shell was simulated and analyzed by using finite element analysis software, and the influence of welding process parameters on the temperature field was studied. The results show that: by changing the ultrasonic amplitude parameters, welding time parameters, initial pressure, etc., the longer the ultrasonic welding time, the temperature of the welding area will increase. In order to ensure the quality of the dialyzer, it should be controlled within 0.8-1 seconds. The increase of ultrasonic amplitude will make the welding temperature continue to rise, and in order to avoid poor welding, the amplitude should not exceed 120 μm. The initial pressure has little effect on the temperature field. [ABSTRACT FROM AUTHOR]

The amount of heat input during welding impacts the weld's thermal and mechanical behavior and the joint's properties. The current study involved conducting AA 6061 and AZ31B Mg dissimilar welding, using friction stir lap welding (FSLW) and ultrasonic vibration-enhanced FSLW (UVeFSLW). The comparison and analysis of the welding load, the weld's macro-microstructure, intermetallic compounds (IMCs), and joint properties were conducted by adjusting the process parameters. The study also examined the effect of ultrasonic vibration (UV) variations on welding heat input. The study demonstrated that it is possible to reduce the welding load by employing UV. Moreover, this impact becomes more pronounced as the welding heat input decreases. Additionally, the material flow in the weld, the width of the weld nugget zone, and the continuous IMC layer are significantly influenced by ultrasonic vibration, irrespective of the heat input during welding. However, the impact on large areas of irregular IMCs or eutectic structures is relatively small. Furthermore, achieving better joint properties becomes more feasible when a higher welding speed is employed for the Al alloy placed on top. Specifically, the impact of UV becomes more evident at higher welding speeds (≥220 mm/min). [ABSTRACT FROM AUTHOR]

In recent years, ceramic membranes have been increasingly used in membrane bioreactors (MBRs). However, membrane fouling was still the core issue restricting the large‐scale engineering application of ceramic MBRs. As a novel and alternative technology, ultrasonic could be used to control membrane fouling. This research focused on the efficiency and mechanism of ultrasonic controlling membrane fouling in ceramic MBRs. The results showed that ultrasonic reduced the sludge concentration in MBR, and the average particle size of sludge was always in a high range. The sludge activity of the system was stable at 6–9 (mg O2·(g MLSS·h)−1), indicating that ultrasonic did not destroy the activity of microorganisms in the system. The extracellular polymer substance (EPS) of the ultrasonic group was slightly higher than that of the control group, while the soluble microbial product (SMP) content was relatively stable. The ceramic membrane of the ultrasonic group has a partial retention effect on the organic components. The application of ultrasonic slowed down the decrease of the hydrophilicity of the ceramic membrane. The main pollutants on the membrane surface exist in the form of aromatic and heteroaromatic rings, alkynes, and so forth. Ultrasonic removes the amide substances from the membrane surface. Membrane fouling resistance is mainly due to membrane pore blockage, accounting for 75.53%. Practitioner Points: Enrich the research on the mechanism of ultrasonic technology in membrane fouling control.The MBR can still operate normally with ultrasonic applied.The time for the ceramic membrane to reach the fouling end point is 2.4 times that without ultrasonic.The main cause of membrane fouling was pore blocking, accounting for 75.53%. [ABSTRACT FROM AUTHOR]

There are a lot of problems with the conventional fusion welding process, so ultrasonic welding has been used for about 20 years and has helped a lot of manufacturing industries, including aviation, medicine, and microelectronics. Ultrasonic welding takes less than one second, making it suitable for mass production. Poor weld quality and joint strength are common issues that industries encounter as a result of this process. Actually, the success and quality of the welding are determined by its control parameters. This research examines the impacts of weld time, vibrational amplitude, and weld pressure on the welding of 0.6 mm thick sheets of two different metals, specifically copper and aluminum (AA2024). Responses, including tensile shear stress, weld area, and T-peel stress, are acquired through experiments that follow a full factorial design including four replicas. The highest recorded tensile shear stress was 4.34 MPa, the maximum weld area measured was 63.6 mm2, and the peak T-peel stress reached 1.22 MPa. A second-order non-linear regression model was constructed using all of these data points, which related the responses to the predictors. Due to the importance of quality in the production sector, the process parameters were determined by the combination of genetic algorithm (GA) and fuzzy logic (FL) approaches. The impact of the weld zone temperature on various quality characteristics has been investigated through experiments. It has been noted from the confirmatory test that FL produces superior output outcomes compared to the genetic algorithm, with FL achieving a fuzzy multi-performance index of 0.94 compared to 0.61 for GA. By conducting microstructural analysis, weld quality levels, including "under-weld," "good weld," and "over-weld," were established. [ABSTRACT FROM AUTHOR]

Ultrasonic welding (USW) is an extensively used joining technique employed in various industries such as automotive, aeronautics, packaging, and others, for joining thermoplastic and thermoplastic composites. The strength of USW can be further enhanced through preferential heating with the induction of energy directors (EDs). The present study investigates water-submerged ultrasonic welding (S-USW) using three different ED designs to join 20% short carbon fibre-reinforced polyamide, commonly referred to as CF/PA. This approach improves weld strength and mitigates material degradation caused by rapid heating, a common issue encountered during USW. The results indicate that the submerged ultrasonic welded (S-USWed) specimen with a semi-circular ED exhibits the highest weld strength, that is, 16.4 MPa compared to specimens welded via conventional USW technique using rectangular and triangular EDs achieving weld strength of 14.69 and 14.3 MPa. [ABSTRACT FROM AUTHOR]

Vibration-assisted welding has evolved as a high-quality weld-production technology. Researchers have recently adopted medium and high frequency assisted welding to improve mechanical qualities. The primary goal of this research is to investigate and optimize process parameters while employing low frequency vibration-assisted welding. The impact strength of 5 mm thick butt-welded MS plates is investigated in this study, employing a novel vibratory approach to impart vibration to the workpiece at frequencies ranging from 150 to 250 Hz during shielded metal arc welding. The Taguchi approach has been used to optimize the process parameters viz. Current, vibration time, and vibration frequency on the impact strength of welded specimens. SEM analysis was also used to examine the microstructure of welded MS plates. The results showed that a low heat input of 81 Amp, a frequency of vibration of 171.97 Hz, and a period of vibration of 110.45 s provided the most effective performance in terms of welded MS plate impact strength. The frequency of vibration has been discovered to be the most crucial characteristic affecting the toughness of the welded joint. For LFVW welded butt joints, a fine grain structure is seen, suggesting enhanced impact strength values owing to weld pool excitation. [ABSTRACT FROM AUTHOR]

This study compares conventional turning (CT) and ultrasonic vibration-assisted turning (UVAT) in machining hardened AISI 52100 steel (62 HRC) with a PVDcoated TiAlSiN carbide tool. UVAT experiments, utilizing an ultrasonic frequency of 20 kHz and vibration amplitude of 20 µm, varied the cutting speed, feed, and depth of cut. Remarkably, UVAT reduced tool wear, extending tool longevity. Surprisingly, power consumption showed no significant differences between CT and UVAT. Mathematical models based on experimental data highlight the substantial impact of the cutting speed on tool wear, followed closely by the depth of cut. For power consumption, the depth of cut took precedence, with the cutting speed and feed rate playing pronounced roles in UVAT. This emphasizes the potential for further research on machinability, particularly exploring different vibration directions on the tool in feed, tangential, and radial aspects. [ABSTRACT FROM AUTHOR]

AbstractSeveral potential benefits in joining thin, dissimilar and highly conductive metals in a solid-state environment make ultrasonic welding (USW) a popular method for building Li-ion battery packs. The USW method is highly complex and relies on multiple factors. In this study, aluminum (AA1100) and nickel (UNS N02200) dissimilar sheets were ultrasonically welded using various process parameters. Plastic deformation, microstructural development, and the corresponding mechanical characteristics of the joints were evaluated qualitatively and quantitatively. The joint strength and critical intensity factor values seemed to rise until the welding duration of 0.3 s, following which there was a subsequent drop in their values. Based on the mechanical analysis, it is observed that the optimal condition records an amplitude of 68 µm, a weld time of 0.3 s, and a clamping pressure of 0.24 MPa. It showed that the joint performance was significantly impacted by the plastic deformation and microstructural changes at the weld region. On the Al side, substantial plastic deformation was observed, and it was primarily attributed to the sonotrode knurls’ penetration. The Al sheet’s thickness was reduced by more than 40%. The microhardness readings at the welding region experienced diminution due to the acoustic softening effect. The cross-section and fracture surfaces of the Al/Ni weld exhibited several distinct microstructural characteristics, such as atomic diffusion, crimped interface, dimple pattern, and swirl pattern flow. Additionally, the diffusion zone is also investigated using X-ray diffraction analysis. These observations offer valuable insights for enhancing weld quality and controlling the overall welding process. [ABSTRACT FROM AUTHOR]

Changes in the quantitative content and specific activity of hyaluronidase enzyme after ultrasonic treatment of solutions of bovhyaluronidase azoximer were studied. Solutions of the finished dosage form of bovhyaluronidase azoximer (Longidase® lyophilizate for preparation of solution for injection, 3000 IE) and bovhyaluronidase azoximer drug substance (Longidase® substance-lyophilizate) were studied. The aim of the study was to determine the effect of ultrasound (US) on the stability of bovhyaluronidase azoximer determined from the measured quantitative content and enzymatic activity of the substance in solution. US at a radiation intensity of 61.4 W/L during treatment in an ultrasonic bath did not significantly affect the quantitative content of the bovhyaluronidase azoximer drug substance in solution, while the decrease in the enzymatic activity of the active substance in Longidase solution after 20 and 30 min of ultrasonic treatment was statistically significant. At the same time, the enzymatic activity of the active substance determined by a biochemical method differed significantly (residual activity from 99.70% to 59.27%) depending on the design features of the nebulizers and the nebulization time after nebulization of the bovhyaluronidase azoximer solution in mesh nebulizers from various manufacturers. Nebulization times of min were least associated with the risk of significant loss of stability of bovhyaluronidase azoximer. [ABSTRACT FROM AUTHOR]

The article explores the ultrasonic welding of lap joints using PEI plates and PEI/CF-fabric prepregs. The authors analyze the structure and mechanical properties of the joints and investigate the impact of different parameters on their formation. They find that the tensile strength of the joints is influenced by the CF-fabric content in the prepregs, with higher content resulting in greater strength. The thickness of the joints also varies depending on the duration of the ultrasonic welding process. The authors conclude that optimizing the parameters can lead to improved functional characteristics of the joints. [Extracted from the article]

AbstractThis study investigates ultrasonic plastic welding to join the carbon fiber-reinforced thermoplastics and 6061Al alloy in a lap-type joint configuration. An interfacial polymer coating through a fluidized bed on aluminum alloy was considered an energy director, as it was essential for concentrating heat at the interface during welding. The significant ultrasonic process setting (weld pressure: 0.5 MPa, weld time: 600 ms, hold time: 1000 ms) was statistically realized for a maximum lap shear strength of the joint that showed the interlaminar shear (first-layer ply) failure of the composite, while the welding interface morphology revealed interdiffusion of thermoplastics with the load-bearing carbon fibers attached to the composite-coating resin mixtures, whereas the coating interface offered a strong adhesion of polymer on the aluminum surface asperities through mechanical interlocking. An efficient multi-material joint was obtained within 1.6 s in comparison to the adhesive bonding technology that required at least 20 min. Additionally, the interfacial coating serves as an insulator, avoiding galvanic corrosion in joints as well as fretting damage. The encouraging findings of this research provide deeper insight into joining thermoplastic composites to metals by ultrasonic plastic welding without the use of a separate energy director, which simplifies the process of industrialization. [ABSTRACT FROM AUTHOR]

Traditional resistance spot welding (RSW) has been unsuccessful in forming quality composite joints between steel– or aluminum–polymer-based composites. This has led to the development of spot welding variants such as friction stir spot welding (FFSW), ultrasonic spot welding (USW), and laser spot welding (LSW). The paper reviewed the differences in the bonding mechanisms, spot weld characteristics, and challenges involved in using these spot welding variants. Variants of RSW use series electrode arrangement, co-axial electrodes, metallic inserts, interlayers, or external energy to produce composite joints. FFSW and USW use nanoparticles, interlayers, or energy directors to create composite spot welds. Mechanical interlocking is the common composite joint mechanism for all variants. Each spot welding variant has different sets of weld parameters and distinct spot weld morphologies. FFSW is the most expensive variant but is commonly used for composite spot weld joints. USW has a shorter welding cycle compared to RSW and FFSW but can only be used for small components. LSW is faster than the other variants, but limited work was found on its use in composite spot weld joining. The use of interlayers in FFSW and USW to form composite joints is a potential research area recommended in this review. [ABSTRACT FROM AUTHOR]

To estimate the possibility of using both low-melting TecaPEI and neat PEI films as energy directors (EDs) for ultrasonic welding (USW) of carbon fiber (CF) fabric–polyetherimide (PEI) laminates, some patterns of structure formation and mechanical properties of their lap joints were investigated by varying the process parameters. The experiment was planned by the Taguchi method with the L9 orthogonal matrix. Based on the obtained results, USW parameters were optimized accounting for maintaining the structural integrity of the joined components and improving their functional characteristics. The use of the low-melting EDTecaPEI film enabled US-welding the laminates with minimal damage to the fusion zone, and the achieved lap shear strength (LSS) values of ~7.6 MPa were low. The use of EDSolverPEI excluded thermal degradation of the components as well as damage to the fusion zone, and improved LSS values to 21 MPa. With the use of digital image correlation (DIC) and computed tomography (CT) techniques, the structural factors affecting the deformation behavior of the USW lap joints were justified. A scheme was proposed that established the relationship between structural factors and the deformation response of the USW lap joints under static tension. The TecaPEI film can be used in USW procedures when very high interlayer adhesion properties are not on demand. [ABSTRACT FROM AUTHOR]

This study investigates the impact of CuO and TiO2 nanoparticles (NPs) in polyvinyl chloride interface of ultrasonically welded glass fiber-reinforced plastic. Welding pressure, duration and holding time were optimized for superior mechanical bonding. Response surface methodology was employed to develop a regression model incorporating welding time, NP weight percentage and thermal conductivity. The results indicated that using a 2 bar pressure, a holding time of 0.5 s, 1 wt.% CuO, and a welding time of 0.45 s, the nanocomposite (NC) demonstrated its maximum breaking load of 2039 N. When the welding time was reduced to 0.4 s for the NC with 1 wt.% TiO2, a slightly lower breaking load of 2036 N was observed demonstrating NC strength and resilience. Therefore, uniform dispersion of 1 wt.% NPs in the polymer matrix increased the welding tensile strength up to 70% of the neat composite. [ABSTRACT FROM AUTHOR]

Ultrasonic Welding can join thin sheets of similar or dissimilar non-ferrous alloys, such as copper, aluminium, magnesium, and brass as it creates a reliable bond that can withstand high loads by producing welds of high quality without the use of filler material. In this investigation, the use of brass, copper and nickel interlayers as well as without interlayer between the Ultrasonic Welded aluminium and magnesium base metals is examined in relation to several welding parameters, including weld pressure, weld time, and hold time. The interlayers used acted as a diffusion barrier, preventing the formation of thicker brittle intermetallic compounds at the interface between the two dissimilar metals. It was figured out that using brass interlayer, exhibited an improvement in joint tensile strength of 140 MPa and as a result of completing the Vickers microhardness test, ultrasonic welded Al/Mg welded alloy sheets with nickel interlayer exhibited the hardness value of 150 HV. [ABSTRACT FROM AUTHOR]

Ti/Al/Ti laminated composite material is an ideal material for high-temperature parts and protective armor in the aerospace field because of its high specific strength and high temperature oxidation resistance. To improve the joint strength, the ultrasonic welding solid-phase joining technology is used to prepare Ti/Al/Ti laminated composites. The results show that the temperature, microstructure and microhardness distribution of the aluminum interlayer are uniform after welding. The recovery recrystallization behavior reduces the hardness of the aluminum interlayer during welding, while the microstructure and microhardness of the upper and lower titanium layers do not change significantly. The tensile shear failure positions of the joints are all located in the lower Al/Ti interface layer, and the highest tensile shear strength reaches 124.4 MPa (1200 W). At this parameter, the plastic constraint reinforcement effect is the most significant, the interface exhibits a small amount of vortex-like morphology, and the local area of the aluminum material melts below the equilibrium melting point. When the welding power reaches 1400 W, the upper surface of the weld is crushed, and the TiAl2 IMC phase precipitates in the Ti/Al interface region.

The motivation for this research stems from the growing demand for solid-phase welding technology to join multilayers metals, particularly in green electric vehicles. Welding of foils and tabs inside battery is a challenging task due to poor joint formation at the interface and low strength. Ultrasonic welding is an efficient, reliable and environmentally friendly bonding method to firmly connect multi-layer copper foils and tabs. Therefore, this is used to achieve electrical bonding within the lithium-ion batteries. This is widely used in production of new energy vehicle batteries. In this work, 40 layers of copper foil were bonded to 0.3 mm nickel-plated copper tabs using ultrasonic metal welding technology. The effect of ultrasonic welding parameters on T-peel strength of joints was systematically investigated by orthogonal experimental design. The maximum T-peel strength of 359.17 N was obtained under optimal parameters (e.g., welding energy 600 J, pressure 0.3 MPa and amplitude 55 %). The variation of welding temperature and amplitude under different welding parameters was measured using infrared thermometer and laser vibrometer. Moreover, the surface, cross-sectional and failure fracture analysis and characterization of specimens with different weld qualities were performed using optical microscopy and scanning electron microscopy (SEM). In addition, the state of Ni layer in cross-section was analyzed using the energy dispersive spectroscopy (EDS) technique after ultrasonic welding. This approach can be straightforward and more appropriate to the development of solid-phase welding method for automotive industry.