Ultrasonic Vibration Treatment Research Articles

Influence of ZrB2 Nanoparticles on Microstructure and Mechanical Properties of Ni-Co Coating

To improve the service life of continuous casting crystallizer, the NiCo-ZrB2 coating was prepared using nanocomposite plating technology. Uniformly dispersed nano-ZrB2 particles significantly enhanced the hardness and wear resistance of the coating. Upon testing, the hardness of the coating exceeded 700 HV, with a friction coefficient below 0.2, which was superior to those of pure NiCo or other nanocomposite NiCo coatings reported previously. Microscopic analysis revealed that the addition of dispersants and ultrasonic vibration treatment had facilitated the homogeneous distribution of nano-ZrB2 within the matrix, thereby promoting the formation of numerous nano-twins. Due to dispersion strengthening, fine grain strengthening, and twinning strengthening, the wear behavior of the coating changed from fatigue wear to abrasive wear, and the wear volume was significantly reduced by 82%. The above findings could potentially extend the service life of the coating, reduce the cost of steel loss per ton, and have broad application prospects in other surface protection fields.

The influence of tensile stress on the strength and residual stress of C19400 alloy under ultrasonic vibration treatment

The C19400 alloy strip used for etching lead frames was studied, and the evolution law of its mechanical properties, residual stress, and microstructure under the ultrasonic vibration and tensile stress treatment was studied. The influence mechanism of ultrasonic vibration and tensile stress on the strength and residual stress of C19400 alloy was determined. The results show that high strength, high conductivity and low residual stress of C19400 alloy can be obtained under the coupling effect of ultrasonic vibration and tensile stress. The tensile strength is 430.57 MPa, the electrical conductivity is 57.73 % IACS, the transverse direction residual stress is −1 MPa, and the rolling direction residual stress is −21 MPa, and the residual stress relief rates are 97 % and 68 %, respectively. Under the coupling effect of alternating load and tensile stress, dislocations are annihilated and reorganized, the dislocation configuration tends to be uniformly arranged, and the dislocation density decreases. Compared with the original cold rolled state, the proportion of high angle grain boundaries of the alloy is slightly increased, and the texture strength is significantly reduced. These results have guiding significance for producing high strength, high conductivity and low residual stress of C19400 alloy.

Effect of Fe Element and Ultrasonic Vibration on the Microstructure and Mechanical Properties of the Cu-TiB2 Composites

Cu-(Fe-Ti)-TiB2 composites were prepared by in situ reaction and vacuum casting with and without ultrasonic vibration. The evolution of the microstructure and mechanical properties of the composite with the variation in Fe element was analyzed. The import of Fe elements could purify the matrix after in situ reaction and the formation of a nanoprecipitated phase, thus improving the strength of Cu-Fe-Ti-TiB2 composites. Meanwhile, compared with the traditional casting process, the Cu-Fe-Ti-TiB2 composites with ultrasonic vibration treatment exhibit uniform TiB2 particle distribution and better properties. The tensile strength and uniform elongation of the composite with a Fe content of 0.7 wt.% reached 511 MPa and 6.02%, increasing by 14.3% and 318% compared to the unalloyed composite, respectively. The tensile strength and uniform elongation of Cu-0.7Fe-Ti-TiB2 composite with ultrasonic vibration treatment increased to 533 MPa and 7.16%, respectively. The TiB2 microscale particles and Fe2Ti nanoscale precipitates with uniform distribution effectively impeded dislocation movement and recrystallization, which improved the tensile strength and stability at elevated temperatures.

Effect of ultrasonic and mechanical vibration treatments on evolution of Mn-rich phases and mechanical properties of Al−12Si−4Cu−1Ni−1Mg−2Mn piston alloys

Effects of ultrasonic vibration (UV) and mechanical vibration (MV) on the Mn-rich phase modification and mechanical properties of Al−12Si−4Cu−1Ni−1Mg−2Mn piston alloys were investigated. The results show that the UV and UV+MV treatments can significantly refine and fragmentize the microstructures. In addition, UV treatment can significantly passivate the primary Mn-rich Al15Mn3Si2 intermetallics. The formation mechanisms of refinement and passivation of the grains and non-dendrite particles were discussed. Compared with the gravity die-cast alloys, the UV and UV+MV treated alloys exhibit improved tensile and creep resistance at room and elevated temperatures. These results can be attributed to the refinement of the α(Al) grains and the secondary intermetallics, the increased proportion of refined heat-resistant precipitates, and the formation of nano-sized Si particles. The ultimate tensile strength of the UV treated alloys at 350 °C exceeds that of commercial piston alloys. This indicates the high application potential of the developed piston alloys in density diesel engines.

Microstructure and flame-retardant properties of the TF550 titanium alloy by ultrasonic vibration assisted laser solid forming

More and more attention has been paid to the application of flame retardancy and surface strengthening of titanium alloys in the aerospace field. In this paper, ultrasonic vibration assisted the laser solid formed (LSFed) TF550 flame-retardant titanium alloy was studied, and the influence of ultrasonic vibration on the microstructure and flame-retardant properties of the LSFed TF550 alloy was analyzed. The results showed that the LSFed TF550 alloy after ultrasonic vibration treatment effectively reduced the generation of pores. When the ultrasonic amplitude was 60 μm, the porosity was the lowest. The porosity of the sample was reduced from 3.84 % to 0.53 %, with the reduction of 86 %. The ultrasonic vibration results in the CET transformation of LSFed TF550 alloy specimen, and the average grain length-width ratio decreases from 5.3 to 1.2, and the microstructure of the specimen changes from the average width of 214 μm to the average grain size of 144±12 μm. Especially when the ultrasonic amplitude is 90 μm, the equiaxial grain size and the grain length-width ratio are the lowest. The effect of ultrasonic vibration at different positions was different. The higher the deposition height, the more columnar crystals in the microstructure and the less equiaxed crystals. When the deposition height was 43 mm, equiaxed crystals and columnar crystals began to coexist. Due to the grain refinement effect of ultrasonic vibration, the number of grain boundaries was increased, and the flame-retardant properties of the LSFed TF550 alloy was improved.

New insights into the influencing mechanism of ultrasonic vibration on interface of Al/Mg bimetal composites by compound casting using simulation calculation and experimental verification

In this work, the numerical simulation of acoustic pressure distribution in ultrasonic vibration-assisted compound casting of Al/Mg bimetal composites was conducted. Relevant experimental verification was also performed to understand the influence of ultrasonic vibration treatment (UVT) on the interfacial microstructures and mechanical properties of the Al/Mg bimetal composites. Results revealed that the acoustic pressure distributions in the AZ91D melt were related to the vibration frequencies. The effective cavitation area at the Al/Mg interface reached the maximum percentage of 95.6 %, with the ultrasonic frequency of 20 kHz. The experimental results found that the Al/Mg interface without UVT was composed of Al–Mg intermetallic compounds (IMCs, i.e., Al3Mg2 and Al12Mg17) layer and eutectic layer. The oxide film and gas gap were existed between the two layers. The Mg2Si particles were gathered at the IMCs layer. The interfacial grains were coarse and their growth was directional. With UVT, the effective cavitation was occurred at the Al/Mg interface. The oxide film was broken, and the gas gap was eliminated. The interfacial microstructures were significantly refined. Due to the accelerated elemental diffusion and solute transfer by UVT, a more homogeneous Al/Mg interface was obtained. The Mg2Si particles were refined and formed at the eutectic layer. The microhardness mismatch of the IMCs layer and eutectic layer was decreased by UVT. The shear strength of the Al/Mg bimetal composites with UVT was enhanced to 62.2 MPa, which increased by 62.8 %, compared with that without UVT.

Microstructure and mechanical properties of Cu–Cr–Zr–ZrB2 composites by novel fabrication process of ultrasonic vibration treatment

Copper matrix composites with dual-scale particles were fabricated through casting with reaction. Ultrasonic vibration has been successfully introduced into the melt at about 1523 K while the microstructural development and mechanism of copper matrix composites with high-performance through a novel method of casting with ultrasonic vibration treatment are investigated. When ultrasonic vibration is applied, the distribution of micro-scale particles is greatly improved. Primary Cr phase convents to non-dendrite and large aggregates of ZrB2 particles are disrupted into small clusters because of acoustic cavitation and acoustic streaming. The ultimate tensile strength and elongation of Cu-1wt%Cr-0.3 wt%Zr-1wt%ZrB2 composite in as-cast state were 321 MPa and 14.37 %, recording a 28.4 % and 14 % increment respectively compared with the sample without treatment. After solution treatment, deformation and aging subsequently, the uniform distribution of reinforcements also decreases the average transverse grain thickness and increases the dislocation density which improve the comprehensive properties.

Tailored gradient nanocrystallization in bulk metallic glass via ultrasonic vibrations

To advance materials with superior performance, the construction of gradient structures has emerged as a promising strategy. In this study, a gradient nanocrystalline-amorphous structure was induced in Zr46Cu46Al8 bulk metallic glass (BMG) through ultrasonic vibration (UV) treatment. Applying a 20 kHz ultrasonic cyclic loading in the elastic regime, controllable gradient structures with varying crystallized volume fractions can be achieved in less than 2 s by adjusting the input UV energy. In contrast to traditional methods of inducing structural gradients in BMGs, this novel approach offers distinct advantages: it is exceptionally rapid, requires minimal stress, and allows for easy tuning of the extent of structural gradients through precise adjustment of processing parameters. Nanoindentation tests reveal higher hardness near the struck surface, attributed to a greater degree of nanocrystal formation, which gradually diminishes with depth. As a result of the gradient dispersion of nanocrystals, an increased plasticity was found after UV treatment, characterized by the formation of multiple shear bands. Microstructural investigations suggest that UV-induced nanocrystallization originates from local atomic rearrangements in phase-separated Cu-rich regions with high diffusional mobility. Our study underscores the tunability of structural gradients and corresponding performance improvements in BMGs through ultrasonic energy modulation, offering valuable insights for designing advanced metallic materials with tailored mechanical properties.

Damage healing mechanisms in polycrystalline copper under unconstraint ultrasonic vibration treatment

The fatigue performance and microstructure of polycrystalline copper treated by one (UUV1), two (UUV2), three (UUV3) passes of unconstraint ultrasonic vibration (UUV) treatment were investigated in this paper. The surface roughness, fatigue life, microstructure, and plastic strain energy before and after UUV treatment were compared. The results revealed that the surface integrity of the sample for UUV treatment higher than that of the original sample, and the microscope observation found that the grain orientation, the dislocation density, the low angle grain boundaries, the plastic strain energy of the damaged sample restored to the original state to a great extent after UUV treatment. The fatigue crack initiation life increased by 3 times after UUV3 treatment.

Effect of ultrasonic vibration treatment on microstructure evolution and mechanical properties of Cu-TiB2 composites

The distribution of second-phase particles is crucial to the mechanical properties of particulate reinforced copper matrix composites (PRCMCs). Ultrasonic vibration treatment (UVT), as an effective technique to disperse second-phase particles in metallic melts, has been extended to treat PRCMCs using a SiAlON sonotrode. In this study, systematic experiments have been conducted to explore the effect of UVT on the microstructures and mechanical properties of in situ Cu-TiB2 composites. The results indicated an optimal duration of UVT for 3 min, featured by an improved distribution of TiB2 particles and superior mechanical properties of the as-cast composite. The ultimate tensile strength, yield strength, and elongation exhibited significant increases of 15.7%, 18.1%, and 36.1%, respectively, compared to the as-cast Cu-TiB2 composite without UVT. Furthermore, these experimental composites were subject to rolling deformation. The results once again demonstrated that the as-rolled Cu-TiB2 composite, treated with UVT for 3 min, stood out as the best. The ultimate tensile strength, yield strength, and elongation of the as-rolled Cu-TiB2 composite were 459 MPa, 422 MPa, and 7.0%, respectively. Based on the microstructural observation, the mechanism underlying the UVT-induced enhancement of mechanical properties was discussed in terms of the non-linear effects of ultrasound cavitation on liquid metals. This work can provide a strategy for producing high-performance PRCMCs through UVT.

Development of prominent bonding strength in Al/Mg bimetal composites prepared by ultrasonic vibration-assisted compound casting: Effects of ultrasonic powers

In this work, the A356/AZ91D bimetal composites were prepared by ultrasonic vibration-assisted lost foam compound casting, and the effects of ultrasonic powers on interfacial microstructures and mechanical properties of the Al/Mg interfaces were investigated. Results revealed that the Al/Mg bimetal composites without ultrasonic vibration treatment (UVT) were heterogeneous, and the Al/Mg interface was composed of Al-Mg intermetallic compounds (IMCs, i.e., Al3Mg2 and Al12Mg17) area and Al-Mg eutectic structures (δ-Mg+Al12Mg17) area. The Mg2Si particles were gathered at the IMCs area and an oxide film that mainly composed of Al2O3 was existed between the IMCs area and eutectic structures area. With UVT, the oxide film was eliminated and the gathered Mg2Si particles were refined and dispersed by the acoustic cavitation effect, and part of the Al3Mg2 and Al-Mg eutectic structures were transformed into the Al12Mg17 due to the promoted solute interdiffusion, which improved the homogeneity of the Al/Mg interfaces. Besides, the grains of the Al/Mg interface with UVT under ultrasonic power of 75 W were significantly refined. The thickness of Al/Mg interface was increased with the increase of the ultrasonic power. Due to the excessive heat induced by UVT under the further increased ultrasonic power, the cooling rates and the degree of supercooling were reduced, resulting in the coarsening of interfacial grains. The microhardness of the Al/Mg interfaces was increased and got more uniform by UVT. The shear strengths of the Al/Mg bimetal composites with UVT were enhanced to 61.4 MPa from 32.4 MPa, with an increase of 89.5 % compared with that of the Al/Mg bimetal without UVT. This could be ascribed to the removal of the oxide film, the refinement of the interfacial grains and the dispersed and refined Mg2Si particles achieved by UVT, which hindered the crack propagation during deformation.

Effect of ultrasonic power density on the quality of fresh wet noodles

In order to enhance the production efficiency in the flour products industry by reducing dough resting time, this study investigated the impact of different ultrasonic densities on starch, protein hydration, and gluten network formation in fresh wet noodles using the ultrasound. The sensory quality, secondary structure, and cross-sectional morphology of the dough were also analyzed. Compared to the control group, the results demonstrate that treatment with an ultrasonic power density of 66 W/L improves the texture of wheat dough, as well as the hydration of starch and protein, the hardness of fresh wet noodles decreased by 14.19 %, and tensile force significantly increased by 33.43 %. Furthermore, Fourier-transform infrared spectroscopy (FTIR) analysis indicated a significant increase in the content of α-helix and an overall increase in the content of β-sheet due to ultrasonic vibration treatment. To summarize, the implementation of ultrasonic treatment exhibits promising potential in reducing the resting processing period while concurrently elevating the overall quality of freshly prepared wet noodles. This is primarily achieved by augmenting the texture, heightening the hydration levels of starch and protein constituents, as well as modifying the gluten network structure.

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.

The Grain Size Evolution Mechanism of A517Q Alloy Steel Fabricated by Laser and Wire Additive Manufacturing Assisted with Different Ultrasonic Vibration Treatments

Additive manufacturing (AM) usually leads to the epitaxial growth of columnar grains in the deposition layer along the construction direction, typically resulting in the decrease in mechanical properties. In this study, A517Q alloy steel was fabricated by laser and wire additive manufacturing (LWAM) assisted with ultrasonic vibration (UV) treatment. The microstructure characteristics of A517Q alloy steel under different UV affected were investigated by OM, XRD, SEM, and EBSD. Compared with the sample without UV, the percentage of equiaxed grains in samples with dual UV increased by 90%. Due to the optimization of grain structure, the tensile strength of the sample with dual UV increased by 29% and the elongation had also been improved. The results showed that due to the cavitation and acoustic flow effects of ultrasonic, the temperature gradient (G) of the molten pool reduced and the solidification rate (R) increased, thus promoting the transformation from columnar grains to equiaxed grains.

Development of Al/Mg bimetal prepared by ultrasonic vibration-assisted compound casting: Effects of interface treatment temperatures

In this work, the A356/AZ91D bimetals were fabricated by ultrasonic vibration-assisted solid-liquid compound lost foam casting. The ultrasonic vibration treatment (UVT) was introduced to the Al/Mg interfaces, and the effects of interface treatment temperatures on the formation, microstructures and mechanical properties of the Al/Mg interfaces were investigated. The results revealed that the Al/Mg interface without UVT was composed of intermetallic compounds area (Al3Mg2 + Al12Mg17 + gathered Mg2Si particles) and eutectic area (Al12Mg17 + δ-Mg). With UVT, phase compositions were not changed, but the distributions were got more homogeneous. The Mg2Si particles at the Al/Mg interfaces were refined and formed at eutectic area. Besides, the thickness of the Al/Mg interfaces were increased. When the UVT performed to the Al/Mg interface of above liquidus temperature of liquid Mg alloy melt, the solid insert was eroded by ultrasonic cavitation, cracks appeared between the Al/Mg interface and AZ91D matrix, which declined the shear strength of Al/Mg interface. When the UVT performed to the Al/Mg interface of temperature close to the formation temperature of it, the Al/Mg interfacial grains were refined and the Al–Mg eutectic structures were formed at intermetallic compounds area, which was not observed in the case of UVT performed to Al/Mg interface of elevated temperatures. The microhardness of the Al/Mg interfaces were increased and became more uniform by UVT, due to the refinement of Mg2Si particles and more homogeneous microstructure. The shear strengths of the Al/Mg bimetals with UVT were increased to 53.9 MPa from 35.5 MPa, with an increase of 51.8%. The fracture morphologies of the Al/Mg interfaces showed typical brittle fracture characteristics. However, the main cracks were hindered and deflected by dispersed Mg2Si particles and transformed to crack branches during deformation and thus enhanced the shear strengths of the Al/Mg bimetal.

Grain-refining mechanism in hypereutectic Al-20Si alloy with minor Sr - Sc - La and ultrasonic vibration treatment

The grain-refining mechanism with minor Sr - Sc - La and ultrasonic vibration treatment (UVT) in the hypereutectic Al-20Si alloy were studied. The results demonstrated that the microstructure of the hypereutectic Al-20Si alloy could be refined significantly, further improve its mechanical properties. The desirable refinement of the microstructure was achieved using 0.2% Sr, 0.15% Sc, and 0.3% La under UVT, achieving the highest grain circularity coefficient, hardness, elongation, and area reduction. The tensile strength was the largest with the addition of 0.2% La. The findings of this study provide theoretical and experimental guidelines for the fabrication of structural materials for application in automotive, aerospace, and deep-sea equipment.

Development of Al/Mg Bimetal Processed by Ultrasonic Vibration-Assisted Compound Casting: Effects of Ultrasonic Vibration Treatment Duration Time.

In this work, ultrasonic vibration treatment (UVT) was introduced to improve the interfacial microstructure and bonding strength of A356/AZ91D bimetal processed via lost foam compound casting (LFCC). The interfacial microstructure and mechanical properties of the Al/Mg bimetal processed via LFCC with different UVT durations were investigated. Results revealed the UVT did not change the composition of phases at the interface. The Al/Mg bimetallic interface consisted of an intermetallic compound area (β-Al3Mg2 + γ-Al12Mg17 + Mg2Si) and eutectic area (δ-Mg + γ-Al12Mg17 + Mg2Si). When the duration of the UVT was increased, the gathered Mg2Si particles at the intermetallic compound area were refined to sizes of no more than 5 μm and became more homogeneously dispersed in the intermetallic compound area and diffused in the eutectic area, which could be attributed to the removal of oxide film and the acoustic cavitation and streaming flow effects induced by the UVT. The microhardness of the Al/Mg bimetallic interface was not obviously changed by the increase in UVT duration. The shear strength of the Al/Mg bimetal was increased with UVT and reached maximum with a UVT duration of 5 s, with a value of 56.7 MPa, which was increased by 70.3%, compared with Al/Mg bimetal without UVT. This could be attributed to the removal of the oxide film at the Al/Mg bimetallic interface, which improved the metallurgical bonding of the Al/Mg interface. Additionally, the refined and homogeneously dispersed Mg2Si particles played an important role in suppressing the propagation of cracks and enhancing the shear strength of the Al/Mg bimetal.

Effects of ultrasonic vibration on microstructure and mechanical properties of 1Cr12Ni3MoVN alloy fabricated by directed energy deposition

Due to the rapid melting and solidification during directed energy deposition (DED) process, the defects and columnar crystals are likely to generate in the deposition layers, which reduce the quality and performance of the whole parts. Therefore, in order to improve the microstructure and mechanical properties of 1Cr12Ni3MoVN alloy manufactured by DED method, ultrasonic vibration (UV) has been employed to assist directed energy deposition process in this work. The results indicate that the high-intensity ultrasonic vibration can weaken the epitaxy growth tendency of crystal grains, and significantly improve plasticity while keeping an approximate strength. In addition, a two-dimensional numerical model is established to simulate the effect of ultrasonic vibration in the molten pool. The simulation results show that ultrasonic vibration remarkably improves the flow velocity and pressure in the molten pool, inducing the cavitation effect that breaks dendritic crystal and affects crystal characteristics. Meanwhile, the acoustic streaming effect changes the thermodynamic conditions and promotes high-temperature diffusion, which uniforms temperature distribution and reduces the temperature gradient in the molten pool. Thus the reduced temperature gradient G and raised solidification growth rate R promote the formation of fine equiaxed crystal characteristics after UV treatment. The product G × R increases and the ratio G/R decreases after UV treatment, resulting in the formation of fine equiaxed crystals.

Ultra-fine Nbss/Nb5Si3 in situ composites with remarkable properties prepared by ultrasonic melt treatment

In order to refine coarse silicide and improve mechanical performance of ternary Nb-20Si-5Mo alloy, ultrasonic vibration treatment for ultra-high temperature melt is successfully applied. The results show that the vibration can improve the fluidity and reduce the shrinkage defects. The hypereutectic microstructure transforms into the fine rod-like eutectic. Due to the solute redistribution in ultrasound field, the Mo-rich layer at Nbss and β-Nb5Si3 phase boundary and the semi-coherent relation can be observed. Mo tends to dissolve in Nbss the matrix phase and inhibit the peritectic reaction. The average size of primary silicide is refined from 49.1 to 2.2 µm with 95.52% refinement efficiency, the compressive strength and fracture toughness of 100 s ultrasonic treated specimen improved 6.84% and 50.75% compared with the as-cast specimen, respectively. The heightened constitutional supercooling and the accelerated nucleation caused by cavitation effect are the main reasons of grain refinement.

In-situ synthesis of TiB2 particulate reinforced copper matrix composites with ultrasonic vibration treatment

In this paper, ultrasonic vibration treatment (UVT) was directly introduced into Cu-Ti-B melt through a Sialon sonotrode. The effects of UVT on the microstructures and properties of TiB2/Cu composite thus fabricated were investigated. The results indicate that with the application of UVT, the average size of the particle agglomerates in the as-cast composite reduced from 24.84 μm to 19.69 μm. Besides, the 3D morphology of the agglomerates changed from irregular to near-spherical under the effect of ultrasound cavitation. The acoustic streaming promotes the flow of the melt to realize a more uniform distribution of particles in the bulk. Dispersion of TiB2 particles alleviates the stress concentration caused by coarse agglomerates, resulting in the concurrent improvements in both strength and ductility of the composite.