Ultrasonic Impact Research Articles

Effect of Ultrasonic Impact Electrospark Treatment on the Flexural Response of Welded Joints of Additively Manufactured Ti-6Al-4V Alloy

Effect of Ultrasonic Impact Electrospark Treatment on the Flexural Response of Welded Joints of Additively Manufactured Ti-6Al-4V Alloy

Study on the surface state induced by ultrasonic impact treatment and its influence on high-temperature tension-tension fatigue behavior

Study on the surface state induced by ultrasonic impact treatment and its influence on high-temperature tension-tension fatigue behavior

Identification of conditions for ultrasonic effect on gas-dispersed medium and creation of radiators to increase the efficiency of coagulation in devices with swirling flow

Relevance. The presence and uncontrolled distribution of aerosols of various substances in the air, which have a negative impact on humans, flora and fauna. This problem is especially acute in the extraction, processing and combustion of georesources. The most effective way to solve the problem is the use of high-intensity ultrasonic vibrations, the effect of which on aerosols causes convergence and agglomeration of small particles into large ones. However, at low concentrations, the particle coagulation efficiency is not sufficient to increase the recovery rate of gas treatment equipment. Therefore, there is a need to find new ways to optimize ultrasonic equipment for coagulation of fine particles in order to increase its efficiency. Aim. To determine the optimal conditions for ultrasonic influence on a swirling gas-dispersed flow, ensuring maximum efficiency of agglomeration of highly dispersed particles. Carrying out comparative studies of coagulation of particles when exposed to ultrasonic fields generated by different types of radiators and their combined effects will make it possible to determine the effectiveness of ultrasonic coagulation and the optimal design scheme of ultrasonic exposure. Objects. Coagulation of particles under ultrasonic impact, formed by various types of radiators. Methods. Computer modeling of the generated ultrasonic field using the finite element method using harmonic acoustic analysis. Finite element modeling and design of disk radiators using modal analysis. To determine the characteristics of the aerosol, a Malvern Spraytec Particle Analyzer was used. Results. The results of calculations and experiments have shown that the use of an extended ultrasonic tubular radiator operating on a bending-diametric mode of vibration and forming a ring standing wave with a sound pressure level of 162–165 dB as the main source of ultrasonic impact for devices with swirling flows may be the most energy efficient. Further increase in the efficiency of coagulation can only be achieved by the combined action of a tubular radiator and a longitudinally oscillating radiator. This significantly modifies the field structure and provides not only an increase in the sound pressure level (up to 167 dB), but also in the number of formed nodal surfaces (up to 44).

Surface softening mechanism based on microstructure analyses under ultrasonic impact condition for Ti-17 titanium alloy

Surface softening mechanism based on microstructure analyses under ultrasonic impact condition for Ti-17 titanium alloy

Effect of ultrasonic impact treatment on surface residual stress, microstructure and electrochemical properties of the hot-rolled S355 steel

The effects of ultrasonic impact treatment (UIT) on the microstructure, corrosion resistance, and surface residual stress of hot-rolled S355 steel were investigated. In addition, the improving mechanism of the UIT induced corrosion resistance was discussed. The results show that the UIT can effectively improve the corrosion resistance of hot-rolled S355 steel, and corrosion current density reduction is demonstrated. Based on the corrosion morphology, it can be found that after the UIT the corrosion pits became shallower, the oxide layer becomes denser, and more flocculent structures appear on the surface as well as the appearance of dense irregular curved structures. Moreover, the residual tensile stress on the surface of the hot-rolled S355 steel is transformed into residual compressive stress after the UIT. The grains are refined, and the microhardness is increased, which implied that the significant plastic deformation has occurred on the surface of the hot-rolled S355 steel. The findings confirm that dense oxides could be generated on the surface of hot-rolled S355 steel treated by ultrasonic impact since the residual compressive stress is introduced, the plastic deformation is induced, and the grains are refined.

Study on the effect of ultrasonic impact on residual stress and deformation in welding arc additive manufacturing

Study on the effect of ultrasonic impact on residual stress and deformation in welding arc additive manufacturing

Study on the friction and wear properties of 7075-T6 aluminum alloy enhanced by milling and ultrasonic impact treatment

This study investigates the effects of milling parameters on the surface friction behavior of 7075-T6 aluminum alloy subjected to ultrasonic impact treatment. A three-dimensional milling and friction-wear model was developed using ABAQUS finite element analysis, examining the influence of milling speed, depth, and feed rate on the coefficient of friction, wear volume, and surface morphology through single-factor experiments. Results indicate that milling parameters affect the friction coefficient in the following order: Vc > f > ap. Specifically, increasing milling speed from 35 m/min to 59 m/min raises the average friction coefficient from 0.305 to 0.387, a 26.88 % increase. At a milling speed of 83 m/min, the friction coefficient and wear volume reach their lowest values of 0.305 and 0.977 mm³, respectively. The wear volume decreases with increasing milling speed and feed rate, while milling depth has a minor effect. The most significant reduction in wear volume, from 5.76 mm³ to 0.977 mm³ (an 83.04 % decrease), occurs as milling speed increases from 35 m/min to 83 m/min. Maximum longitudinal slip during the reciprocating motion primarily occurs at the ends, with both positive and negative peak offsets. Surface damage from 304 stainless steel balls against the 7075-T6 alloy involves adhesive and abrasive wear. At a milling depth of 35 μm, friction-induced compounds in the transfer film mainly consist of Al, C, Fe, Zn, Mg, and Cr.

Experimental evaluation of multiple-component residual stress distribution in a dissimilar metal repair joint of ferritic/martensitic steel using the asymmetric-cut and the symmetric-cut contour method

A thick multi-pass butt-welded ferritic/martensitic steel (P91) joint is prepared and the local region of the weld is repaired with an ENiCrFe-3 nickel-based alloy using the manual metal arc welding method. The repair weld including part of the base metal is then subjected to ultrasonic impact treatment (UIT). A three-cut contour method, including two asymmetric cuts and one symmetric cut, is developed in the present study to obtain the two-dimensional residual stress distributions at different locations, and the stress release after multiple cuts is considered to get the original stress distribution before cuts. The measurement procedure is introduced in detail. The longitudinal stresses in the repair weld and the initial weld of the P91 steel joint, as well as the transverse stress at the weld center, are finally obtained. The effects of the dissimilar metal repair weld at the local region on the longitudinal and transverse welding residual stresses are investigated. In addition, the applicability of UIT to mitigate the surface stress in nickel-based alloy repair weld is analyzed. The results show that the transverse and longitudinal stresses in the nickel-based alloy repair weld are both tensile stresses, the maximum longitudinal stress is close to the yield strength of the B91 weld metal and occurs in the heat-affected zone of the repair weld located in the initial weld. Repair welding causes the internal transverse compressive stress region to be narrower than in the original weld. UIT can be used to introduce compressive stress to the surface layer of the nickel-based alloy repair weld.

β-Grain refinement in WAAM Ti-6Al-4 V processed with inter-pass ultrasonic impact peening

As-deposited Wire-Arc Additive Manufactured (WAAM) Ti-6Al-4V parts typically contain large columnar β-grains on a centimetre scale, with a strong 〈001〉 fibre texture, leading to anisotropic mechanical properties and unacceptable scatter in damage tolerance. Inter-pass deformation, introduced by the application of Ultrasonic Impact Peening (UIP) across each added layer, has been shown to be effective in refining the β-grain structure and achieving a weaker texture. The depth of deformation and the grain refinement mechanism induced by UIP have been investigated by combining advanced electron backscatter diffraction (EBSD) characterization with a ‘stop action’ observation technique. UIP facilitates a similar refinement mechanism and nearly the same depth of deformation as conventional machine hammer peening, with the advantages of a much higher strain rate, lower peak force, and two orders of magnitude lower impact energy, making it a faster and more economical process. β recrystallization is seen within the deformation zone during re-heating through the α → β transition. Although new recrystallized β-grains formed in the UIP surface-deformed layer to a shallower depth than that of remelting, recrystallization initiated ahead of the melt pool and the recrystallized grains grew downwards to a greater depth before remelting. These refined grains were thus able to survive and act as nucleation sites at the fusion boundary for epitaxial regrowth during solidification, greatly refining the grain structure.

Effect of interlayer ultrasonic impact on the microstructure, mechanical and corrosion properties of wire arc additive manufacturing AZ31 Mg alloy thin wall

AZ31 Mg alloy thin walls are prepared using wire arc additive manufacturing (WAAM) and interlayer ultrasonic impact (UI) techniques with cold metal transition (CMT) serving as the heat source. The microstructure, mechanical and corrosion properties of thin walls prepared by WAAM and WAAM + UI are studied. Results showed that the recrystallization area fraction along traveling direction (TD) increased by 68.6% after UI treatment, and many fine equiaxed crystals were formed, resulting in grain refinement, anisotropy reduction, mechanical and corrosion properties improvement. The average grain size along TD decreased from 66.6 ± 3.5 μm to 32.7 ± 1.6 μm. Through UI treatment, the ultimate tensile strength (UTS) and elongation (EL) along TD increased from 205 MPa to 230 MPa and 13.5%–17%, respectively. The anisotropic percentage of UTS and EL were decreased from 10.8% to 4.5%, and 42.1%–9.7%, respectively. Electrochemical experimental results showed that the average corrosion rate along TD decreased from 1.93 mm year−1 to 1.53 mm year−1. Grain refinement, dislocation density variation and texture strength reduction were the main reasons for these results.

The Effects of Different Ultrasonic Composite Surface Modifications on the Properties of H13 Steel for Shield Tunnel Machine Cutter Ring

Tunnel boring machines (TBMs) are exposed to the impact of the ground shattering force and the friction of sandstone during excavation work, and are prone to wear and breakage, and other failures. Traditional heat treatment processes cannot simultaneously achieve the required high-energy composite structure of hard external and tough internal properties for cutter rings, leading to inadequate wear resistance and impact toughness under working conditions. This study utilizes H13 steel as the base material, and based on a study of carburizing, nitriding, and ultrasonic impact processes for H13 steel analyzing the effects of different high-energy composite modification processes on the hardness distribution, microstructure, and residual stress of H13 steel, the mechanisms by which high-energy composite modification processes affect the wear resistance and impact resistance of H13 steel are revealed. The results indicate that the wear amount and impact toughness of the sample subjected to carburizing and ultrasonic surface rolling composite strengthening were 1.9 mg and 27.34 J/cm2, demonstrating the best wear and impact resistance. This combination of properties allows the H13 steel cutter ring to achieve the optimal overall performance in terms of wear resistance and impact resistance.

Synchronous ultrasonic impact assisted laser cladding CoCrFeNiMo high entropy alloy coating: Microstructure and wear property

Synchronous ultrasonic impact treatment (UIT) is proposed to enhance the microstructure and wear property of laser cladded CoCrFeNiMo high entropy alloy (HEA) coatings on 45 steel. FCC phase with minor tetragonal σ phase and rhombic η phase are form in both conventional and UIT treated coatings. Due to the plastic deformation and high-frequency vibrations induced by UIT, dislocation interactions lead to recrystallization process at the top region coating. With the application of UIT, the columnar grains at top region of the coating transform into fine equiaxed grains owing to recrystallization. The fragmentation of dendrites occurs in the middle region of the coating, resulting in reduced dendrite arm spacing. The results also show the defects, such as pores and microcracks, are effectively eliminated within the coating. Microhardness and wear property of the coating are remarkably enhanced owing to fine-grain strengthening and second-phase strengthening. The average friction coefficient decreases from 0.56 for the conventional sample to 0.49 for the UIT treated sample, and the wear mechanism evolved from a combination of abrasive, fatigue, and oxidized wear to predominantly fatigue and oxidized wear. It indicates that synchronous ultrasonic impact assisted laser cladding is a potential method to fabricate high-performance HEA coatings.

Comparative Study of UPV and IE Results on Concrete Cores from Existing Structures

Dynamic non-destructive methods (NDT) are particularly attractive owing to their time and cost efficiency when compared to conventional uniaxial compressive strength tests. However, the results of these methods are highly scattered; therefore, they are primarily used for qualitative material characterization. One of the most important NDT results is the calculation of the dynamic Young’s modulus, which is associated to the uniaxial compressive strength (UCS) of concrete. The ultrasonic pulse velocity (UPV) is the most commonly used NDT. The limitation of this method is that it directly depends on knowledge of the Poisson’s ratio, and an assumption of its value must be made. This assumption results in highly scattered results. In contrast, the impact echo method (IE) can result in a dynamic Young’s modulus calculation without knowing the Poisson’s ratio. The limitation of this method is that it is dependent on the specimen’s slenderness, which in turn depends on the Poisson’s ratio. This study investigates the IE method’s applicability to short cylinders. A comparison of the UPV and IE methods is made, and the error in the dynamic Young’s modulus value derived by assuming Poisson’s ratio value in the UPV method is calculated. The authors conducted a numerical analysis and recently proposed the use of a shape correction factor (SCF) to apply the IE results for short cylinders, considering the influence of the slenderness (L/D) of the samples. For the first time worldwide, an extensive experimental study on 232 concrete samples with L/D ≈ 1.0 confirmed the wide spread of UPV test results and showed that it can lead to an error on Young’s Modulus determination by up to 50% owing to the adoption of an arbitrary Poisson’s ratio value. In contrast, using the SCF yields IE results with a ±2% error. A new methodology, ultrasonic pulse impact echo synergy (UPIES), is proposed by performing both UPV and IE tests on the specimens and using the SCF. The Poisson’s ratio and, consequently, the Young’s modulus can be accurately determined. Doi: 10.28991/CEJ-2024-010-09-03 Full Text: PDF

Research on influence factors of small punch test to evaluate the mechanical properties of gradient nanostructured material

Abstract The influence factors of small punch test (SPT) were investigated to evaluate the mechanical properties of gradient nanostructured (GNS) materials. The gradient nanostructure was prepared on the top layer of S30408 austenitic stainless steel by ultrasonic impact treatment (UIT). The mechanical properties of the GNS material were obtained using SPT and correlated with those obtained by standard tensile tests. The results indicate that, when the specimen thickness is 0.5 mm, the sphere diameter is 2.4 mm, the punch velocity is 0.5 mm min−1, and the gradient nano-grained layer is placed face-on in the mold, the GNS material exhibits better plastic deformability. The SPT specimen achieves better bearing capacity, and the mechanical properties of the GNS material obtained by SPT are more accurate. The yield strength and tensile strength of the GNS material were also evaluated by analytical and empirical methods in SPT. The error is approximately 10% compared with the standard tensile test results, which is within the allowable range.

Predicting fatigue life and crack growth rate of TC4 titanium alloy based on PINN before and after ultrasonic impact treatment

This study conducted fatigue crack growth rate (FCGR) experiments on TC4 titanium alloy specimens under different stress ratios (R=0.06, 0.1, 0.5) before and after ultrasonic impact treatment (UIT) conditions. Based on this, a Physics-Informed Neural Network (PINN) model was employed to predict the FCGR of TC4 titanium alloy. As a control group, the traditional Walker FCGR formula was fitted using experimental data. The results indicate that the stress ratio R does not significantly affect the FCGR of TC4 titanium alloy. Under the same range of stress intensity factor (ΔK), the FCGR (da/dN) decreases with increasing R. The FCGR prediction established by the PINN model can well reflect the nonlinear characteristics of the crack growth process rate. The coefficient of determination R2 for fitting the experimental data reached above 0.9900, generally higher than the 0.9545 of the Walker formula. Although the degree of dispersion increased after UIT, the PINN model demonstrated stable prediction accuracy compared to the Walker formula. In addition, when calculating the fatigue crack growth life using the cycle-by-cycle method, the PINN model also exhibits stable prediction accuracy compared to the Walker formula, and this advantage becomes more apparent with increased data dispersion.

Wear and Friction Performance of Alumina-Reinforced Composite Coating on Ti-6Al-4V Alloy Produced by Combining Ultrasonic Impact Treatment and Air-Oxidation

Wear and Friction Performance of Alumina-Reinforced Composite Coating on Ti-6Al-4V Alloy Produced by Combining Ultrasonic Impact Treatment and Air-Oxidation

Promoting densification and strengthening effect of ultrasonic impact treatment on Haynes 230 alloy manufactured by laser powder bed fusion

Laser powder bed fusion (LPBF) has been extensively investigated owing to its high geometry formation accuracy and excellent mechanical properties. However, the LPBFed Haynes 230 parts typically display poor tensile and wear properties due to internal porosity. In this work, the ultrasonic impact treatment (UIT) was applied as a post-treatment to the LPBFed Haynes 230 alloy, porosity and microstructure modulation were performed to improve the strength properties and wear resistance. The pore closure and microstructure were studied by numerical simulations and experiments, and the mechanisms of increasing densification and strength were discussed. Results show that UIT can effectively close pores and reduce porosity, the internal porosity of the ultrasonic impacted layer for one, two, and three times decreases by 63.6 %, 70.9 %, and 81.8 %, respectively. Pore closure is attributed to the residual compressive stress and shear stress introduced by UIT. Besides, the UIT weakened texture strength and refined grains, especially promoting the formation of fine grains. Meanwhile, it also promotes the formation of a high dislocation density and improves the phase structure distribution. Furthermore, the ultimate tensile and yield strengths of the optimal impact process increased by 9.6 % and 34.6 %, respectively. The improvement in strength was attributed to dislocation, grain boundary, and promoting densification strengthening. The average friction coefficient reduces by 4.9 %–14.6 % by refining the surface grains and increasing dislocation density. This work has verified the feasibility of improving the mechanical properties and pore closure of the LPBFed Haynes 230 alloy by UIT.

Study on the effects of ultrasonic impact treatment on the local mechanical properties of welded joints based on the digital image correlation

In this study, UIT was used to strengthen the local mechanical properties of welded joints, and the influence of UIT on the local mechanical properties of welded joints was analyzed by 3D-DIC technology. At the same time, the mechanism of UIT on the microstructure and properties of welded joints was revealed by microstructure observation. By measuring the full-field strain process of the welded joint after UIT under uniaxial tensile load, the curve of the strain in the local area with time is obtained. At the same time, the Ramberg-Osgood equation and Considère criterion are used to fit the material constitutive relationship at each point in the local area. The results show that UIT significantly improves the yield strength of the WM and the tensile strength of the BM. This study provides technical and theoretical support for the preparation of high-quality welded joints by UIT technology.

Multidimensional ultrasonic vibration machining modeling of SiCp/Al cutting forces with different volume fractions: Experiments and numerical simulations

The cutting properties of the particles of aluminum-based silicon carbide (SiCp/Al) and the base material are so disparate that it is challenging to ensure the surface quality of machining. The cutting force significantly influences the quality of the machined surface. Therefore, real-time cutting force prediction is paramount for ensuring the workpiece's desired surface quality. This paper presents a 3D ultrasonic milling force model, established from four aspects: cutting formation force, extrusion friction force, SiC particle crushing force, and ultrasonic impact force. The model is based on the ultrasonic action of the cutting process and the unique removal characteristics of the material. A 3D ultrasonic milling system was constructed to experimentally verify the milling force model. The effects of each parameter on the milling force were analyzed through orthogonal experiments, which resulted in the effects of depth of cut, rotational speed, volume fraction, ultrasonic amplitude, and feed rate. The ultrasonic amplitude, feed rate, and other factors were found to influence the milling force to varying degrees. The milling force was observed to be 42.47 %, 22.37 %, 10.85 %, 12.67 %, and 11.64 % affected by the factors mentioned above, respectively. The single-factor experiment was conducted to analyze the cutting force at different machining parameters. The experimental results and the MATLAB numerical simulation results exhibited a similar trend of change. The maximum absolute error between the two was 12.71 %, with an average absolute error of 3.735 %.

Effects of ultrasonic impact on surface characterization of S355 steel welded joint

The effects of ultrasonic impact treatment (UIT) on the residual stress, the microhardness, the nano-hardness, the microstructure, the electrochemical corrosion resistance, the corrosion morphology, and the chemical composition of the S355 steel welded joints were investigated. In addition, the mechanism of improving the electrochemical performance of the S355 steel welded joints by the UIT was studied. The results showed that the UIT could significantly improve the electrochemical corrosion resistance of the S355 steel welded joints. The corrosion potential and impedance were increased, and the corrosion current density was decreased with the increasing of the UIT time. According to the corrosion morphology, it was observed that after the UIT, the number of corrosion pits in the welds and heat-affected zones of S355 steel welded joints significantly decreased, along with reductions in the depth and size of the pits. After the UIT, the grain size of the S355 steel welded joints was refined, and both the microhardness and the nano-hardness of the welded joint were increased, which indicated that substantial plastic deformation occurred on the S355 steel welded joint. Moreover, the UIT could significantly reduce and transform residual tensile stress into residual compressive stress in areas adjacent to the welds, and the residual compressive stress could be increased with the increasing of the UIT time. It can be concluded that the introduced compressive residual stress, the grain refinement, and the generated plastic deformation were the main factors in improving the electrochemical corrosion resistance.