Effect Of Ultrasonic Vibration Research Articles

Effect of Ultrasonic Treatment on Ti/Al Composite using Squeeze Casting: Microstructural Analysis and Mechanical Properties

To segregate the Titanium (Ti) from the reinforcements of the molten scrap of Titanium/Aluminum (Ti/Al) composite, application of ultrasonic vibration is known to be one of the sound techniques. Various studies have been looked at the effect of ultrasonic vibration on the melting process, however not much have been investigated with respect to the solidification process. To fabricate Ti/Al composites in situ, ultrasonic vibration can be effectively used to compress the solidifying melt during the casting process. In this line, the present study focused to investigate the influence of ultrasonic vibration and squeeze pressure on solidification behavior of the α-Al matrix, characteristics of the matrix-reinforcements interface, and distribution of reinforcements. The experimental data indicated that when the amplitude was 60 μm, the Vickers hardness, yield strength, and tensile strength of composites increased by 8.6, 3.9, and 3.1 %, respectively, due to gravity casting. While the squeeze pressure was increased from 50 to 100 MPa, the mean grain size decreased from 90 to 60 μm during the ultrasonic aided squeeze casting (SC) process. However, as the squeeze pressure was raised, the microstructures became coarser and the mechanical characteristics weakened. Yield strength, and tensile strength were increased by 18.7% and 3.2%, respectively, when the squeeze pressure was 100 MPa.

Achieving high strength 316L stainless steel by laser directed energy deposition-ultrasonic rolling hybrid process

Laser directed energy deposition (LDED) has attracted as a progressive additive manufacturing technique in fabricating the stainless steel components. The rapid melting and solidification velocity under LDED process induces the appearance of pores and the columnar dendritic, which degrades the strength of alloys. Here, a self-developed LDED-UR (ultrasonic rolling) synchronous manufacturing equipment is developed to fabricate the 316L stainless steel, and the characterization of microstructure and mechanical properties are studied. Results show that the size and fraction of pores are significantly reduced by LDED-UR processing, and fine equiaxed grains are obtained under the combined effects of ultrasonic vibration and roller pressure. With the severe plastic deformation, the average grain size of LDED-UR sample is decreased from 76.10 μm to 26.23 μm (LDED sample), and high angle grain boundaries transforms to low angle grain boundaries. Meanwhile, the dislocation density in LDED-UR sample is increased compared to the LDED sample. Owing to the grain refinement and dislocation strengthening, the average microhardness, yield strength, ultimate tensile strength and elongation of the LDED-UR sample reach 268.18 ± 13.90 HV0.2, 442 MPa, 771.2 MPa, and 49.8 %, respectively, which are larger than those of LDED sample (214.13 ± 13.76 HV0.2, 396 MPa, 682 MPa, and 45.5 %). This implies that the superior mechanical properties are obtained by employing in-situ ultrasonic rolling under LDED process. The insight of the influence of microstructure on mechanical properties extends a new approach for enhancing the mechanical properties of LDED alloys.

Study on Characteristics of Ultrasound-Assisted Fracture Splitting for AISI 1045 Quenched and Tempered Steel.

Ultrasonic vibration-assisted con-rod fracture splitting (UV-CFS) was used to carry out the fracture experiment of 1045 quenched and tempered steel. The effect of ultrasonic vibration on the fracture properties was studied, the fracture microstructure and the evolution of dislocations near the fracture were analyzed and the microscopic mechanism was analyzed. The results show that in the case of conventional fracture splitting without amplitude, the dimple and the fracture belong to ductile fracture. With the increase in ultrasonic amplitude, the plasticity and pore deformation of the con-rod samples decrease at first and then increase; when the amplitude reaches a certain point, the load required for cracking is reduced to a minimum and the ultrasonic hardening effect is dominant, resulting in a decrease in the plasticity of the sample, a cleavage fracture, a brittle fracture, the minimum pore deformation and high cracking quality. The research results also show that with the increase in ultrasonic amplitude, the fracture dislocation density decreases at first, then increases, and dislocation entanglement and grain breakage appear, then decrease, and multiple dislocation slip trajectories appear. The changes in the dislocation density and microstructure are consistent with the above results.

Grain refinement and Laves phase dispersion by high-intensity ultrasonic vibration in laser cladding of Inconel 718

Laser cladding is a promising surface modification and repair technology for fabricating Inconel 718 parts. However, laser cladding may produce coarse grains and brittle Laves phase, leading to a significant decrease in performance. The application of high-intensity ultrasonic vibration in laser cladding is able to refine grain and reduce Laves phase. This study investigates the distribution characteristics and the evolution mechanism of the grains and Laves phase in laser cladding with high-intensity ultrasonic vibration. The effects of high-intensity ultrasonic vibration on alteration of grain characteristics and the reduction of Laves phase were analyzed and discussed through ultrasonic vibration-assisted laser cladding experiments. Results indicate that high-intensity ultrasonic vibration promoted a columnar-to-equiaxed transition, and reduced the grain size from 75.6 μm to 48.8 μm. Furthermore, the Laves phase had a decrease of 47.1% in the volume fraction, and transformed from a long-striped shape into a fine granular shape, leading to a more homogeneous distribution of elements in Laves phase. The change in the grains and the Laves phase is attributed to dendrite fragmentation and inhibition of element segregation by nonlinear effects of ultrasound including cavitation and acoustic streaming. The findings of this study confirm the significant benefits of applying high-intensity ultrasonic vibration in laser cladding and provide insight into the underlying evolution mechanisms of high-intensity ultrasonic vibration for grains and Laves phase.

Effect of Welding Parameters on Al/Mg Dissimilar Friction Stir Lap Welding with and without Ultrasonic Vibration.

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).

The effect of Sn interlayer on weld structure, intermetallic compounds, and joint properties of Al/Mg friction stir welding with ultrasonic assistance

ABSTRACT: The formation of intermetallic compounds (IMCs) is a primary factor that affects the welding joint between dissimilar materials. In this study, experiments were performed using Al/Mg friction stir welding (FSW) and ultrasonic vibration enhanced FSW (UVeFSW) with varying thicknesses of Sn interlayer. Detailed characterization and tests were conducted to explore the effect of Sn interlayer with or without ultrasonic vibration on weld surface morphology, macro-micro structure, generation of IMCs, and joint tensile strength. The study discusses the effect of ultrasonic vibration coupled with Sn interlayer and provides ideas for IMCs regulation when joining dissimilar materials. The study showed that adding a Sn interlayer cannot eliminate the generation of Al-Mg IMCs, but it can significantly reduce their thickness. Applying ultrasonic vibration with Sn interlayer can further reduce the thickness of Al-Mg IMCs and improve the interface microstructure from ‘IMC + matrix +IMC + matrix’ multilayer structures to simple IMCs structures. Furthermore, the highest joint strength was achieved when the Sn interlayer thickness was 0.1 mm during FSW. UVeFSW’s joint strength can be further improved with 0.05 mm and 0.1 mm Sn interlayer.

Investigation of the effect of ultrasonic vibration on the performance of the friction drilling by FEM simulation

The friction drilling process is very important in various industries such as automotive, aerospace, and oil and gas industries. Therefore, they have always sought to find methods to improve this process. One of these methods is to optimize the application of ultrasonic vibrations in the process, and limited research has been done in this regard. The current research aims to investigate the effect of ultrasonic vibrations simultaneously with the parameters of drilling on the friction drilling process to optimize this process with the help of finite element simulation. Due to the nature of the complex transformations of the process, a Coupled Eulerian–Lagrangian model of the process was first created in the Abaqus software. Then, the process simulation was carried out in the presence and absence of ultrasonic vibrations. Rotational speed, feed rate, and amplitude of vibrations are the influencing parameters, and sheet temperature and axial force, and torque applied to the tool are the parameters investigated in this research. The results show that higher rotation speed and lower feed rate lead to a reduction of axial force and torque. Also, the application of ultrasonic vibration reduces up to 50.48% the axial force and up to 46.67% torque, and this reduction is improved by increasing the range of vibrations. The optimal mode was selected After analyzing 12 different modes based on the lowest amount of axial force and torque on the pin. It was found that the ideal mode occurs at a feed rate of 4.23 m/s and a rotation speed of 3000 rpm, with a 20-µm range. These findings and optimizing drilling parameters bring new horizons in material bonding techniques in various industries.

Investigation of processing characteristics of PCD in ultrasonic-assisted graphene powder mixed EDM

Polycrystalline diamond is widely used in many fields including ultra-precise machining, optical material and semiconductor electronic devices due to its excellent physical properties. However, traditional mechanical processing methods of polycrystalline diamond leads to severe tool wear, low efficiency and high costs. Although electrical discharge machining can overcome some limitations, it usually exhibits a low material removal rate and poor surface quality. This study aims to explore the effect of graphene powder and ultrasonic vibration on polycrystalline diamond by electrical discharge machining. It was found that the synergistic effect of graphene powder and ultrasonic vibration can achieve a good surface quality. The results show that ultrasonic-assisted powder mixed electrical discharge machining can obtain the smallest surface roughness (1.98 μm) at low parameter and the biggest material removal rate (0.773 mg/min) at high parameter compared with ultrasonic assisted electrical discharge machining and powder mixed electrical discharge machining. In addition, after ultrasonic-assisted powder mixed electrical discharge machining, the minimum value (0.807) of ID/IG is obtained. For polycrystalline diamond, this study also proposes a removal mechanism that diamond converts into graphite and is peeled under tensile stress.

Effect of Ultrasonic Vibration on Microstructure and Antifouling Capability of Cu-Modified TiO2 Coating Produced by Micro-Arc Oxidation

Ti and its alloys have received wide attention in marine engineering. However, the limited anti-biofouling capability may hinder their wide application. In the present work, micro-arc oxidation (MAO) with and without the introduction of ultrasonic vibration (UV) has been conducted on metallic Ti substrate in an aqueous solution containing Na2Cu-EDTA to produce a Cu-modified TiO2 coating. Microstructural characterization reveals that the introduction of UV increased the thickness of the coating (ranging from ~13.5 μm to ~26.2 μm) compared to the coating (ranging from ~8.1 μm to ~12.8 μm) without UV. A relatively higher Cu content (~2.13 wt.%) of the coating with UV relative to the coating (~1.39 wt.%) without UV indicates that UV enhances the incorporation of Cu into TiO2. Further, both electrochemical properties and the response to sulfate-reducing bacteria (SRB) were evaluated, revealing that UV introduction endows Cu-modified TiO2 coating with enhanced corrosion resistance and antifouling capability. The present results suggest that ultrasound-auxiliary micro-arc oxidation (UMAO) obviously enhances the surface performance of Ti alloys for promising applications in marine engineering.

Effect of ultrasonic vibration on microstructural evolution, clad defects, and surface properties in laser direct energy deposition of Inconel 625

Laser direct energy deposition (DED) has some accompanying issues, such as existence of micropores, elemental segregation at grain boundaries, intergranular corrosion, etc. Therefore, the current work aims for a reduction in clad defects and enhancement in surface properties for laser direct deposition of Inconel 625 by implementing ultrasonic vibration. The acoustic streaming and cavitation effect induced by ultrasonic vibration results in the breaking of columnar grains, along with grain refinement and better elemental distribution in the matrix during the solidification process. The investigation is carried out for deposition using a 240 W Yb-fiber laser under the application of ultrasonic vibration with a variable amplitude of 6–13 μm (frequency: 33–28 kHz). A relatively higher vibration amplitude was found more efficient in converting long columnar grains into finer and uniformly distributed equiaxed grains, with a significant reduction in micropores. Further, it resulted in a shorter molten pool lifetime because of the generation of more nucleation centers, leading to better cooling. The above effects resulted in higher microhardness of the deposited layer. Further, the wear and corrosion resistance showed an improvement with the application of vibration, which may be due to the finer equiaxed grains, less porosity, and better elemental distribution at a higher vibration amplitude.

Effect of ultrasonic vibration-assisted laser cladding frequency on the microstructure and properties of Fe-0.5C-15Cr alloy cladding layers

In this paper, Fe-0.5C-15Cr wear and corrosion resistant alloy coating was prepared on 3Cr13 stainless steel surface by ultrasonic vibration assisted laser cladding technology. The effects of ultrasonic vibration frequency on the microstructure, microhardness and corrosion resistance of the coating were studied. The results show that the length of the dendrites of the cladding layer decreased significantly after ultrasonic vibration is applied, the grains size is refined significantly, and the morphology of the grain boundary carbides changed from fishbone-like to short rods, when the vibration frequency is 20.2 kHz, the grain refinement is the most significant, and the orientation of the dendrites is obviously weakened. The hardness of the applied ultrasonic vibration specimens increased by 10–20 HV0.2 relative to the non-ultrasonic specimens, with the increase of vibration frequency, the hardness of the cladding layer firstly increased and then slightly decreased, and the peak appeared at 20.2 kHz. The coefficient of friction of the specimens when the ultrasonic frequency of 20.2 kHz is applied is lower than that of the specimens with non-ultrasonic frequency by 12.8 %, and the abrasive wear rate is reduced by 14.3 %. After ultrasonic vibration, the pitting potential of the cladding layer increases, the dimensional passivation current density decreased, the width of the passivation zone becomes wider, and the intergranular corrosion reactivation rate decreased, When the ultrasonic frequency is 20.2 kHz and 20.4 kHz, the pitting corrosion resistance and intergranular corrosion resistance of the cladding layer are significantly improved. This is because the cavitation effect, resonance effect and acoustic flow effect of ultrasonic vibration promote the non-uniform nucleation, refine the dendrites and intergranular carbides, and promote the redistribution of the corrosion-resistant element Cr in the in-grain martensite and grain boundary carbides, increasing the content of Cr in the matrix, and thus improving the wear resistance and corrosion resistance of the cladding layer.

Investigation of the effect of ultrasound during explosion welding on the formation of the structure and properties of the aluminum-steel composite

The paper presents the results of experimental studies of the effect of ultrasonic vibrations during explosion welding on the formation of the structure and properties of the connection of steel with aluminum. It is shown that the introduction of ultrasound during explosive loading has a significant effect on the structure and properties of the aluminum-steel compound. The chemical composition of the areas of the melted metal is considered. The results of the tensile strength of aluminum+steel composite layers are presented. It has been experimentally established that the introduction of additional ultrasound energy in the process of explosive loading of an aluminum-steel compound contributes to a significant reduction in the amount of molten metal at the junction boundary throughout the studied range.

Investigation of the Flow Stress Model for Cr4Mo4V Bearing Steel under Ultrasonic Vibration Conditions

To investigate the mechanisms behind the effect of ultrasonic vibration on the plastic deformation of materials, the flow stress model of Cr4Mo4V was established according to the dislocation dynamics and thermal activation theory, which considers the effect of dislocation density evolution on plastic deformation under ultrasonic vibration conditions. The effect of amplitude and strain rate on the flow stress was analyzed by fitting the stress-strain data obtained from an ultrasonic vibration-assisted tensile (UVAT) single-factor test. To investigate the influence of strain rate and vibration duration on the acoustic effect, comparative tests with and without vibration were performed for various strain rates. The results showed that the flow stress decreased significantly in the tensile test with ultrasound compared to the test without ultrasound, and the degree of reduction increased with increasing amplitude. In addition, the nonlinear relationship between the acoustic softening effect and the strain rate was analyzed. The result demonstrates that the dislocation density absorbs the ultrasonic vibration energy, which results in slip and proliferation. Macroscopically, due to a greater susceptibility to plastic deformation, the dislocation density shows residual hardening at the end of the ultrasound. Finally, the average absolute relative error (AARE) between predicted flow stresses and experimental results under three ultrasonic conditions using the developed model were 4.49%, 1.27%, and 5.64%, which proved the validity of the model.

Synergistic effects of ultrasonic vibration and isothermal treatment on the peritectic transformation and microstructure evolution of Cu–Sn alloy

To facilitate and even complete the peritectic transformation, the ultrasonic vibration (USV) and isothermal treatment were applied to the solidification process of Cu–70Sn alloy. It was found that the peritectic transformation was difficult to carry out due to the limited atomic diffusion under the normal solidification condition. With the single isothermal treatment, the peritectic transformation could be enhanced to some extent, with a small amount of η phase (Cu6Sn5) formed relying on the coarse elongated primary ε phase (Cu3Sn), but the further prolongation of isothermal time led to the abnormally coarsening of microstructure. When the molten alloy was subjected to 1500W USV and 30 min isothermal treatment, the peritectic transformation was dramatically facilitated. The ultrasonic-induced effects of cavitation and acoustic streaming play an important role in the remarkable reduction in the curvature radius of primary ε phase, thereby enhancing the diffusion of Sn solute atoms from the liquid phase to the interior of ε phase at the following isothermal stage. Accordingly, the transformation degree of ε phase to η phase was increased up to 77 %, and there was a high volume fraction of primary ε phase could thoroughly complete the peritectic transformation.

Effects of ultrasonic cavitation on microstructure and surface properties of Mn–Cu alloy

In the presented study, the effects of ultrasonic vibration on microstructure and surface properties of Mn–Cu alloy were investigated. At the early stage of ultrasonic cavitation treatment, grains of Mn–Cu alloy are refined, nanocrystals and amorphous bands are produced. As the ultrasonic cavitation treatment proceeds, the face-centered cubic structure is transformed into the body-centered tetragonal structure, and the martensitic phase transformation arises. The transformation is accompanied by plastic deformation and the formation of dislocations. The generation of martensite is caused by the stress and strain. Due to grain refinement, dislocations, and generation of martensite, the surface hardness of Mn–Cu alloy is enhanced, and the friction coefficient decreases. The resistance to wear is thereby improved.

Effects of ultrasonic vibration on wear and corrosion resistance of WC particles reinforced coating produced by laser cladding (invited)

Effects of ultrasonic vibration on wear and corrosion resistance of WC particles reinforced coating produced by laser cladding (invited)

Effect of radial ultrasonic vibrations on wear properties of CBN grains in high-speed grinding of PTMCs

Effect of radial ultrasonic vibrations on wear properties of CBN grains in high-speed grinding of PTMCs

Multi-regional microstructure control using ultrasonic-assisted directed energy deposition for Al-Cu alloy

The uneven microstructure and element distribution between the inner-layer zone (INZ) and the inter-layer zone (ITZ) resulting from the thermal cycling effect during the directed energy deposition process with the electric arc energy source (DED-Arc) can lead to inferior mechanical properties. In order to address this problem, the ultrasonic treatment of the 2319 Al-Cu alloy during the DED-Arc process is investigated to control the multi-regional microstructure quantitatively. Therefore, the effect of ultrasonic vibration during the DED-Arc process on grain morphology, distribution of precipitates and mechanical properties in different regions are explored in detail. The formation mechanism of differential microstructure is elucidated by using an ultrasonic-heat-flow coupling simulation model for the DED-Arc process. The results indicate that ultrasonic vibration refines the average grain size, leading to 16% and 40% reductions at the molten pool center (MPC) and boundary (MPB), respectively. However, the grains in the semi-melting zone (SMZ) experience coarsening due to the reduced temperature gradient after ultrasonic treatment. The enhanced melt flow rate is considered responsible for both the homogenization of Cu and the fragmentation of the θ-Al2Cu phase. The higher subgrain boundary density in the ITZ leads to an average microhardness of approximately 60 HV, which is lower than that found in the INZ (72.3 HV). Meanwhile, ultrasonic treatment increases the average strength and elongation by 38.1% and 17.5%, respectively, mainly through precipitation strengthening, which results in a strength increment of 91.6 MPa. The slip directions tend to be consistent after ultrasonic vibration, which is conducive to crystal sliding and displays excellent ductility.

Fracture behavior of AZ31B magnesium alloy under high-temperature ultrasonic-assisted shearing with related ductile-brittle transformation mechanism

A wide width is one of the fundamental requirements for magnesium alloy sheets to fulfill the lightweight needs of the aerospace and rail transportation industries. Nevertheless, ensuring the dimensional integrity of wide-format magnesium alloy sheets is a challenge in most manufacturing facilities. Simultaneously, processing operations are susceptible to encountering production issues, including but not limited to significant loss of raw materials, elevated costs, environmental contamination, and safety risks. Therefore, to fulfill the operational demands of the hot rolling finishing line for wide sheets made of magnesium alloy, the present study employed ultrasonic-assisted shearing (UAS) to carry out a high-temperature shearing test investigation on the AZ31B magnesium alloy sheet. In this research, we employed scanning electron microscopy, optical microscopy, and a micro-hardness tester to investigate the relationship between ultrasonic amplitude and fracture behavior, deformation mechanism, and mechanical properties of magnesium alloy sheets following exposure to ultrasonic vibration. The fracture morphology of the sheet fracture demonstrates that the behavior of the magnesium alloy sheet fractures under ultrasonic vibration changes from ductile fracture under conventional shearing to brittle fracture under ultrasonic-assisted shearing. The primary cause of this transformation between ductile and brittle is the effect of ultrasonic vibration on the material's internal energy. High-energy ultrasonic amplitude action causes magnesium to absorb a significant amount of ultrasonic energy. This results in an increase in the number of dynamic re-crystallization grains in the material organization, a decrease in the number of twins, and significant refinement of the grains. The sheet's hardness also changes along the rolling and normal directions, with a uniform distribution. The magnesium alloy sheet's fracture quality is optimal when the ultrasonic amplitude is 10 μm in the UAS process. This treatment results in notable enhancements in the section's straightness and brightness. Our study aims to advance the mass manufacturing of wide-format magnesium alloy sheets by investigating a cost-effective and high-yield technique for shearing magnesium alloy sheets.

Flow and thermal coupling analysis in metal droplet-based 3D printing: Evolution mechanism and regulation strategy under ultrasonic vibration

Formation of uniform pileup morphology and excellent bonding strength between two adjacent metal droplets are essential in droplet-based 3D printing. However, due to the unstable included angle (“gap”) of the pileup droplets generated by the complex coupling effect between the fluid flow and thermal deformation during the printing process, the successive pileup droplets tend to form poor accuracy morphologies, non-uniform properties, and low-quality bonding strength of the formed microstructure. Since the unstable flow and thermal deformation of the liquid metal is inherent properties in droplet-based 3D printing technique with the same parameter conditions, the morphological deterioration or even instability pileup process still remain common challenge in this technique. Here, the effects of velocity and thermal behaviors on the morphology and size of the pileup droplets were revealed. To accomplish this, a droplet pileup numerical model based on the volume of fluid (VOF) was developed to analyze the spreading and solidification mechanism of the pileup process. In addition, a series of printing experiments with the successive pileup of Sn droplets, generated by a self-developed piezoelectric micro-jet device (PMJD), were conducted to demonstrate the effects of impacting velocity and solidified temperature on the pileup morphology. The evolution mechanisms of impacting velocity and heat accumulation effect and its influence on the dimensional accuracy were revealed. Finally, the originality of this work is an ultrasonic-assisted metal droplet pileup (UAMDP) method was first proposed and applied to effectively regulate the pileup morphology and improve the bonding strength. The evolutions of the influence of the velocity field, temperature field, and pileup behaviors during the spreading process were analyzed thoroughly. A surface morphology analysis further showed the effect of ultrasonic vibration on the contact region between two pileup droplets. And experiments showed that such UAMDP (under voltage of VP-P = 15 V) has 5.9 times enhancement in the adhesion tangential force between two pileup metal droplets. This study provides a foundation for further development of metal droplet-based 3D printing technology.