Welding-induced residual tensile stresses in 316 L stainless steel (SS) components posed potential threats to the safety of fusion reactors. To effectively regulate these stresses, a PSO-CNN-LSTM hybrid optimization framework integrating finite element (FE) simulations was proposed to optimize ultrasonic impact treatment (UIT) process parameters. In this framework, a CNN-LSTM surrogate model was established to accurately predict post-UIT residual stresses, replacing time-consuming FE iterations. Subsequently, particle swarm optimization (PSO) was employed to locate the global optimal parameters. Results indicated that PSO-CNN-LSTM hybrid optimization framework achieved exceptional prediction accuracy, with R-square (R2) values of 0.9538 and 0.9474 for training and testing, respectively. Through global optimization, the longitudinal residual stress was reduced by 13.7%, and a robust optimal parameter combination (i.e. 200 kHz, 200 μm, and 6.7 mm) was determined. Furthermore, the intrinsic mechanism linking surface plastic deformation, grain refinement, and residual stress regulation was elucidated via multi-scale microstructural analyses and microhardness tests. This study provided a precise and efficient data-driven strategy for enhancing the structural integrity of fusion reactor components.

Purpose The purpose of this paper is to quantitatively investigate the effect of ultrasonic impact treatment (UIT) process parameters (including impact velocity, needle diameter, overlapping distance and offset distance) on welding residual stress (WRS) in a doubly-welded rib-to-deck joint (DRJ). Meanwhile, a multi-parameter optimization method was proposed to optimize the effect of UIT processes. Design/methodology/approach A 3D finite element model simulating UIT was developed to regulate the WRS in DRJ and experimentally validated. A multivariable UIT optimization method, employing the Robbins–Monro stochastic approximation algorithm with gradient feedback, was proposed, and its efficacy was demonstrated through numerical experiments. Subsequently, the effect of different UIT process parameters on the WRS of DRJ was investigated using the optimized parameters. Findings Optimized parameter combination achieved 43.5% higher surface compressive stress and 119% deeper compressive layer. Impact velocity and needle diameter mainly affect residual stress magnitude at the DRJ weld toe, while overlapping distance and offset distance govern the residual stress distribution patterns in the DRJ. Originality/value This study deepens the understanding of UIT's regulatory effects on WRS in the DRJ. The application of UIT-driven WRS control demonstrates significant potential to enhance fatigue life and provide practical guidance for fatigue-resistant design of orthotropic steel decks.

Different graphene derivatives/MXene hybrid fillers reinforce gelatin composite films in food packaging applications.

An efficient and highly sensitive Ag@NiO/g-C3N4 nanocomposite sensor is synthesized through a simple sol–gel ultrasonic treatment process for the detection of acetaminophen.

The quality of produced water in oil and gas field is complex and difficult to treat. Ultrasonic water treatment technology has a good effect on degradation of organic polymers and demulsification, but its application is limited due to energy consumption and other reasons, and it has not been industrialized in oil and gas field water treatment. Through ultrasonic mechanism research, water quality characteristics analysis and a large number of small simulation tests, the test results show that for complex produced water with high salt content, high turbidity and high emulsification, under the ultrasonic frequency of 39.5kHz, ultrasonic time of 30min and operation conditions of 25°C, the oil removal effect can be achieved at 66W power. The oil content is reduced from 77.9mg/L in the inlet water to 1.87mg/L in the outlet water, and the oil removal rate can reach more than 95% to meet the expected demand. In the case of the mature development of green electricity technology, this study provides a new technical idea for the efficient treatment of produced water in oil and gas fields, and provides a basic research basis for the industrial application of ultrasonic treatment process and the collaborative application of combined with other processes.

CeO2 loaded on L-tryptophan functionalized graphitic carbon nitride colorimetric-fluorescent dual-channel detection

Effect of ultrasonic pretreatment on textural properties and sensory attributes of cooked faba beans

In the processing of oxidized, refractory ores, the removal of oxide films from the mineral surface is an important task. Oxide films create a passivating effect leading to the transition of the metal surface into an inactive state, which slows down physical and chemical processes, such as bacterial oxidation process. In order to avoid this effect, it is advisable to act on the surface of the crushed ore with ultrasonic radiation. The analysis of Russian and foreign inventions — technologies of ore processing using ultrasound has shown acceleration of mass transfer in the process of ore leaching, significant intensification of the leaching/oxidation process, increase in the degree of extraction of valuable metals, reduction in the duration of the process as a whole. However, due to the high energy consumption of the ultrasonic treatment process, it is important to determine the optimal value of ultrasonic intensity at which the oxide films are removed from the ore grains, but the grains are not destroyed, not crushed. In this work we calculated the optimum value of ultrasonic vibration intensity capable of removing oxide films from the surface of cobalt-coppernickel sulfide ore particles in order to avoid creating a passivating effect on their surface. As the calculation showed, the optimal value of the ultrasound intensity lies in the range from 17 to 28 W/cm2, at a frequency of ultrasonic vibrations of 22000 Hz.

Microstructure, mechanical and corrosion properties of FeCrNiCoMnSi0.1 high-entropy alloy coating via TIG arc melting technology and high-frequency ultrasonic impact with welding

The ultrasonic melt treatment (UMT) is widely used in the fields of casting and metallurgy. However, there are certain drawbacks associated with the conventional process of single-source ultrasonic (SSU) treatment, such as the fast attenuation of energy and limited range of effectiveness. In this study, the propagation models of SSU and four-source ultrasonic (FSU) in Al melt were respectively established, and the distribution patterns of acoustic and streaming field during the ultrasonic treatment process were investigated by numerical simulation and physical experiments. The simulated results show that the effective cavitation zone is mainly located in a small spherical region surrounding the end of ultrasonic horn during the SSU treatment process. When the FSU is applied, the effective cavitation zone is obviously expanded in the melt. It increases at first and then decreases with increasing the vibration-source spacing (Lv) from 30 mm to 100 mm. Especially, when the Lv is 80 mm, the area of effective cavitation zone reaches the largest, indicating the best effect of cavitation. Moreover, the acoustic streaming level and flow pattern in the melt also change with the increase of Lv. When the Lv is 80 mm, both the average flow rate and maximum flow rate of the melt reach the highest, and the flow structure is more stable and uniform, with the typical morphological characteristics of angular vortex, thus significantly expanding the range of acoustic streaming. The accuracy of the simulation results was verified by physical experiments of glycerol aqueous solution and tracer particles.

Microstructural evolution and strengthening mechanisms of CMT directed energy deposition-arc with interlayer ultrasonic impact treatment manufactured AZ31 magnesium alloy

ABSTRACT The effect of ultrasonic treatment (UST) and thermal annealing (THA) post-processes on the mechanical properties and the related microstructural mechanisms of the tensile pre-strained 316 stainless steel was investigated. It was shown that both processes reduce the microhardness and the yield point as well as increasing the elongation of the pre-deformed alloy. A 10% reduction of the yield point and 28% increase in the elongation was observed after the higher power UST (500 W), while an enhanced ductility of 56% and 41% reduction of the yield point was measured for the high-temperature THA (800°C) treated steel. The increased ductility was related to de-twinning and dislocation annihilation mechanisms, which increase the mean free path distance of dislocations. The de-twinning mechanism was proposed as the boundary migration mechanism and reverse gliding of the partial dislocations by cyclic shear stress for the THA and UST processes, respectively. Unlike the UST process, the high-temperature thermal annealing was associated with the formation of M23C6 precipitates, which causes depletion of alloying elements from the vicinity of grain boundaries and makes the alloy more prone to intergranular corrosion. Compared with THA, the advantages of the UST process are as follows: a rapid and straightforward process, low energy consumption, enhanced ductility without significant reduction in strength, and inhibition of grain boundary precipitation.

Three dimensional flower like ZnFe2O4 ferrite loaded graphene: Enhancing microwave absorption performance by constructing microcircuits

Internal stress relief and microstructural evolution by ultrasonic treatment of austeno-ferritic 2205 duplex stainless steel

This study presents an application of ultrasonic technology in the high voltage liquid insulation domain towards the reduction of pour point of vegetable oil samples for the utilization of vegetable oils as liquid insulation in cold climate areas on power transformers. Pour point reduction has been achieved by processing the vegetable oil samples by using ultrasonic treatment process with 100 W and 30 kHz ultrasonic waves for various exposure times of 15, 30, 45 and 60 min. Edible vegetable oils such as sunflower oil, palm oil, sesame oil and non edible vegetable oils such as honge oil, neem oil and punna oil are considered as two categories of vegetable oils for this experimental investigation. Ultrasonic treatment process results in the reduction of pour point of vegetable oils to meet out the standard value of pour point for liquid insulation as per IEEE Standard C57.147, 2018. A significant reduction in pour point temperature of vegetable oil samples have been obtained with an increased exposure time. The obtained variations in pour point after exposure with ultrasonic waves may be due to the possible changes in crystallization kinetics of fatty acids components of vegetable oil samples due to energy input of ultrasonic waves. The experimental results have given a way towards the positive encouragement and development with ultrasonic treatment for achieving low pour point vegetable oils as liquid insulation in power transformers for applications on cold climatic areas.

Ultrasonic treatment affects emulsifying properties and molecular flexibility of soybean protein isolate-glucose conjugates

A high-performance soybean meal-based plywood adhesive prepared via an ultrasonic process and using significantly lower amounts of chemical additives

A quantitative understanding of the role of ultrasonic treatment (UST) process variables on microstructure and mechanical properties is critical for the development of process maps for manufacturing metal matrix composites (MMCs). This article presents a novel mathematical framework to delineate the functional correlations among ultrasonication time, grain refinement, and hardening in SiC nanoparticle‐reinforced Al matrix composites. UST generates microbubbles and deagglomerates SiC to increase heterogeneous nucleation sites synergistically. The increase in volumetric nucleation density due to SiC addition exhibits slow exponential kinetics with varying ultrasonication time. An outstanding grain refinement efficiency of 62.8% is achieved upon ultrasonication for 90 s. The contributions to an increase in the hardness due to grain refinement and SiC dispersion are isolated to develop correlations between ultrasonication time and hardening. Hardening increases exponentially with treatment time due to the reduction of interparticle distance from sonication‐induced SiC dispersion. These fundamental mathematical correlations constitute a significant advancement toward the development of ultrasonic process maps and MMC manufacturing technology.

Ultrasonic degradation of selected dyes using Ti3C2Tx MXene as a sonocatalyst.

Fatigue properties of welded Strenx 700 MC HSLA steel after ultrasonic impact treatment application