Ultrasonic Assistance Research Articles

Macroscopic mechanism of ultrasonic vibration in ultrasonic-assisted metal forming

Ultrasonic vibration-assisted metal forming has gained increasing attention and applications recently, but the mechanism of ultrasonic effects is still not clear. In this paper, a new finite element method to simulate all ultrasonic effects in metal forming was proposed, and the volume effect and surface effect were quantitatively analyzed in upsetting and U-groove extrusion. It was found that the ultrasonic effects were quite different in upsetting and extrusion. In U-groove extrusion, the acoustic softening effect reduced the flow stress of the material by 20.0 MPa, far less than that in upsetting (91.7 MPa). The friction decreased by 82.7% due to the surface effect, which was more significant than that in upsetting (decreased by 58.3% and 33.3% at the top and bottom interfaces). Ultrasonic vibration increased the feature height in U-groove extrusion from 0.653 mm to 1.427 mm with a growth rate of 118.5%. The acoustic softening effect increased the feature height by 0.063 mm (8% of the total increase), while the surface effect increased the feature height by 0.711 mm (92% of the total). The surface effect plays a key role in affecting material flow in extrusion. It is suggested that this method could accurately reflect the deformation behavior of materials with ultrasonic assistance, and is of great value for process design and in-depth study of the microscopic mechanism in ultrasonic forming.

Optimisation of surface residual stresses using ultrasonic-assisted milling for wire-arc additive manufactured Ni alloy components

Nickel alloys are cost intensive materials and generally classified as difficult-to-cut material. However, machining of these materials is needed especially in case of alloy 36 (1.3912), which is commonly used in mould construction for the production of fibre-reinforced composites. With regard to repair, modification and manufacturing of such components, additive manufacturing offers significant economic advantages. Nevertheless, subsequent machining steps are needed to achieve the final component contour and defined surface conditions. Dependent on the material and machining process conditions, detrimental tensile residual stresses may be the result on the machined surface, having negative impact on the component performance and safety. In this investigation, machining experiments were carried out on wire arc additive manufactured components made of alloy 36, varying the cutting speed and the feed rate. In addition, the conventional milling process (CM) was compared with a modern, hybrid machining process, the ultrasonic-assisted milling (US). The cutting forces and the surface-near residual stresses were analysed using X-ray diffraction. A significant improvement of the machinability as well as the surface integrity by using the ultrasonic assistance was observed, especially at low cutting speeds. The CM induced mainly tensile residual stresses, the US mainly compressive residual stresses.

Cellular localisation and quantification of Camptothecin in different plant parts of Nothapodytes nimmoniana (J. Graham) Mabberley of Sri Lankan origin.

Nothapodytes nimmoniana (Icacinaceae) is a rich source of Camptothecin (CPT), an anti-cancer prodrug. Efficient extraction of CPT from various plant parts is crucial for better recovery of this pre-drug. To investigate the distribution of CPT in plant parts and to compare the methods of extraction on CPT yield to evaluate how cellular localisation affects the efficiency of extraction methods. Transverse sections of plant parts were observed under a ultraviolet (UV)-fluorescence microscope for the fluorescence that the CPT molecule emits when exposed to UV radiation. Dried plant parts were extracted using 90% methanol with ultrasonic assistance, hot ethanol (61% ethanol at 60°C), and chloroform-methanol (4:1, v/v). The CPT in plant parts were detected by thin-layer chromatography (TLC) and confirmed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and high-performance liquid chromatography (HPLC). Quantification was carried out by HPLC. Blue fluorescence indicated a prominent accumulation of CPT in roots compared to leaf with petiole, twigs, and stembark. This accumulation was observed in upper and lower epidermis of the leaf, isolated strands of fibres in the phloem in the petiole, and groups of idioblast cells in the cortex. The ultrasonic-assisted extraction with 90% methanol showed the highest CPT yield in the root (1.91 ± 0.02 mg/g of dry weight), followed by stembark and the least in leaves [0.02 ± 0.01 mg/g (dry weight)] irrespective of the method of extraction. However, hot ethanol extraction gave the highest CPT yield for twig and leaf, indicating the necessity of tissue-specific extraction methods for better recovery of CPT.

Preparation of Cellulose Nanocrystals by Synergistic Action of Ionic Liquid and Recyclable Solid Acid under Mild Conditions

Cellulose nanocrystals (CNCs) are nanoscale particles made from cellulose. They have many unique properties such as being lightweight, stiff, and renewable, making them promising for a variety of applications in a wide range of industries, including materials science, energy storage, and biomedicine. In this paper, a two-stage (swelling-SA-catalyzed) method including IL pretreatment and solid acid hydrolysis process was developed to extract CNCs with high purity and good thermal stability from microcrystalline cellulose (MCC). In the first stage, the swelling of MCC in ionic liquid was studied with the assistance of ultrasonication, and it was found that the amorphous regions became more disordered while the crystalline areas were selectively retained under the conditions of 30 min of reaction time, 45 °C of temperature, 2% of ionic liquid water content and 1:4 mass ratio of cellulose to ionic liquid. CNCs were extracted using solid acid hydrolysis, with a 45 wt% solid acid to cellulose ratio and a 5.0 h hydrolysis process at 45 °C. The morphology, crystallinity, surface characteristics and thermo stability of the sample were characterized by atomic force microscopy (AFM), X-ray diffraction (XRD) and thermogravimetric analysis (TGA), respectively. Results demonstrated the highly thermostable CNCs were successful extracted with rodlike shape of 300 ± 100 nm in length and 20 ± 10 nm in width. Solid acid recovery and reuse were also studied, revealing a promising candidate that can reduce the environmental impact associated with chemical products.

Ultrasonic assisted electrochemical discharge milling of complex glass microstructure with high-quality

IntroductionWith the rapid development of MEMS, the demand for non-conductive hard and brittle material microstructure is increasing. Electrochemical Discharge Machining (ECDM) is one of the most effective methods to machine non-conductive materials like glass and ceramics. However, in the milling process, the problem of discharge pits of different sizes and large thermal cracks caused by excessive discharge energy and heterogeneous energy distribution leads to low machining accuracy, poor stability and surface quality. ObjectivesIn order to solve the above dilemmas and improve the machining quality and stability, a newly developed micro Ultrasonic Assisted Electrochemical Discharge Milling (UAECDM) method is proposed in this paper. MethodsFirstly, a mathematical model is established to reveal the material erosion mechanism in the machining process. Secondly, the influence of ultrasonic vibration on gas film formation and discharge energy is analyzed by theory and simulation. Finally, the effects of ultrasonic amplitude and machining parameters on the quality of microchannels are experimentally studied and optimized by single factor optimization. The machining technology of UAECDM is creatively proposed. ResultsThe experimental results show that adding ultrasonic assistance and using the optimized machining parameters can refine the film thickness, optimize the energy distribution and stabilize the current signal. With assistance of ultrasonic vibration and optimized parameters, a smooth micro channel with width of 118.9 μm was fabricated, and its surface roughness was 0.23 μm, which was 80.99 % declined from 1.21 μm of ECDM. The successful fabrication of microchannel array, two-dimensional and three-dimensional complex glass micro-structures with surface roughness of about 0.2 μm also proves the excellent machining ability of UAECDM. ConclusionIt is proved that UAECDM can effectively improve machining accuracy, stability and surface quality. UAECDM is a desirable method to fabricate micro-channel on glass and will have a very broad industrial application prospect in the future.

Effect of Vibration Direction on Two-Dimensional Ultrasonic Assisted Grinding-Electrolysis-Discharge Generating Machining Mechanism of SiCp/Al.

This study proposes the mechanism of two-dimensional ultrasonic assisted grinding- electrolysis-discharge generating machining (2UG-E-DM). It analyzed the influence of vibration directions on grinding characteristics and surface morphology through the motion simulation of an abrasive. Comparative experiments with different vibration directions verified the effect of ultrasonic assistance on the weakening of the grinding force, the widening of the surface pits, and the leveling of the surface morphology of SiCp/Al composites. Simulation analysis of a single abrasive particle verified the test results. The results of machining tests at different amplitudes showed that as the workpiece and tool amplitude increased, the grinding force of the normal force decreased faster than that of the tangential force. The effect of surface electrolysis discharge machining was significant, and the number of exposed particles increased, but the residual height of the surface and the surface roughness were reduced by vibration grinding. When the two-dimensional amplitude was increased to 5 μm, the axial and tangential vibrations increased the grinding domain, and the dragging and rolling of the reinforced particles significantly reduced the surface roughness, which obtained good surface quality.

Influence of Milling Conditions on AlxCoCrFeNiMoy Multi-Principal-Element Alloys

Multi-Principal-Element or High-Entropy Alloys (MPEAs/HEAs) have gained increasing interest in the past two decades largely due to their outstanding properties such as superior mechanical strength and corrosion resistance. However, research studies on their processability are still scarce. This work assesses the effect of different machining conditions on the machinability of these novel alloys, with the objective of advancing the introduction of MPEA systems into industrial applications. The present study focuses on the experimental analysis of finish-milling conditions and their effects on the milling process and resulting surface finish of CoCrFeNi, Al0.3CoCrFeNi and Al0.3CoCrFeNiMo0.2 alloys fabricated via Spark Plasma Sintering. Ball-nose-end milling experiments have been carried out various milling parameters such as cutting speed, feed per cutting edge, and ultrasonic assistance. In situ measurements of cutting forces and temperature on the tool edge were performed during the experiments, and surface finish and tool wear were analyzed afterwards. The results exhibited decreasing cutting forces by means of low feed per cutting edge and reduced process temperatures at low cutting speed, with the use of ultrasonic-assisted milling. It was shown that the machinability of these modern alloys through conventional, as well as modern machining methods such as ultrasonic-assisted milling, is viable, and common theories in machining can be transferred to these novel MPEAs.

Continuous-Flow Diazotization of Weakly Basic Aromatic Amines in a Microreaction System

Due to the characteristics of high transfer efficiency, controllable process, and intrinsic safety in microreactors, there have been many studies on the miniaturization of diazotization reactions. However, diazotization of weakly basic aromatic amines is difficult to be reformed by continuous microreaction technology due to its poor solubility. In this paper, first, by improving the crystallization process, the miniaturization of diazotization with low solid content was realized. The effects of various parameters (flow rate, temperature, reagent dosage, and concentration) on the reaction yield were investigated systematically. As for high solid content, by introducing the gas–liquid Taylor flow and ultrasonic assistance, the mass transfer process was strengthened, and the slurry flow pattern was improved. Finally, at 0.40 mol/L, a residence time of 94 s in the delay loop with a 5 °C cold trap was employed to produce a diazonium salt in 96% yield with high stability.

Crystal evolution of nano-sized CoCr2O4 synthesized by a modified sol–gel method

The present study provides a comprehensive assessment of the synthesis, crystal evolution, and degree of inversion of the spinel CoCr2O4 (i.e., cochromite) by a modified sol–gel method using propylene oxide and ultrasonication. Ultrasonic assistance promotes the dissociation and dispersibility of Co2+ and Cr3+ precursors, contributing to the hydrolysis reaction to form hydrated ions. Propylene oxide serves as a proton scavenger to provide the conditions needed for homogeneous gelation. Heat treatments at different temperatures (400, 550, and 700 °C) for different durations (1, 4, and 8 h) have been applied to follow the crystal evolution and the inversion of the spinel system. The formation of CoCr2O4 particles was observed at approximately 400 °C. An increase in calcination temperature induced particle size growth (from 12 to 42 nm) and sintering effects. A significant decrease in the specific surface area (from 144 to 33 m2 g−1) was observed with changes in the lattice parameter (8.304–8.334 Å). Raman, XPS, XRD, and Rietveld analyses indicated the presence of a pure cochromite phase. The Bertaut method has been applied to monitor the inversion process of CoCr2O4 during post-synthesis heat treatment. The spinel conformation became a regular type beyond 700 °C, whereas a fully inverted structure was obtained at lower temperatures. The modified sol–gel method may be convenient for large-scale production to synthesize other spinel-type compounds.

Evolution of microstructures and intermetallic compounds at bonding interface in friction stir welding of dissimilar Al/Mg alloys with/without ultrasonic assistance

Complete understanding of the evolution behaviors of the microstructures and intermetallic compounds (IMCs) along the interface materials flow path in friction stir welding (FSW) of dissimilar Al to Mg alloys is of great significance. In this study, conventional FSW and ultrasonic vibration enhanced FSW (UVeFSW) experiments of Al/Mg alloys were performed, and the instantaneous evolution features of the interface materials around the tool were "frozen" by using the "sudden stop" and simultaneous cooling techniques. The microstructures and IMCs formation at different locations around the exit hole were observed and characterized by scanning electron microscope, energy dispersive spectrometer and transmission electron microscope. It was found that before the materials started to deposit near the back of the tool, “IMC+Mg+IMC+Al” multilayer microstructure and simple IMC layer with (β+γ) sequentially emerged on the Al/Mg interface. With the application of ultrasonic vibration, the multi-layered interface structure only appeared at the middle stage of materials flow around the pin, and ultrasonic vibration just began to play a suppression role on the growth of two sub-layers IMC at a position where the materials deposit. With assistance of ultrasonic vibration in UVeFSW, the tool drove a larger volume of Mg alloy to move toward the retreating side, and the final IMCs thickness was thinner than that in FSW.

Low-temperature metallization of SiC ceramic with Sn0.5Zn via ultrasound assisted formation of an amorphous transition layer

The metallization of the SiC ceramic was realized with Sn0.5Zn at a relatively low temperature of 250 °C with the assistance of ultrasonication. This process avoided the use of high temperature, vacuum, or long holding time in traditional metallization methods. Results indicate that fine metallization without defects can be completed under ultrasonication excitation for 20 s. The bonding mechanism was forming a nano-scale layer of non-uniform but continuous amorphous zinc suboxide (ZnO1-x) (even when the Zn was only 0.5 (wt%)), which acted as a transition region from the SiC ceramic substrate to the Sn0.5Zn metal layer. The tensile strength between the Sn0.5Zn layer and the SiC was 12.3 MPa. The acoustic pressure in the liquid Sn0.5Zn pool was calculated via COMSOL Multiphysics software. The simulation results show that alternating positive and negative acoustic pressure existed in the liquid Sn0.5Zn metal, with the highest amplitude of more than 107 Pa, thereby generating the cavitation effect. The collapse of cavitation bubbles resulted in micro-jets, hot spots, and a high cooling rate, promoting the movement of Zn atoms toward the SiC surface and the formation of ZnO1-x.

Highly efficient catalytic hydrolysis of NH3BH3 over Ru nanoparticles anchored to chitosan-h-BN composite

The hydrolysis of ammonia borane (AB) is an efficient and safe way to produce hydrogen. A proper catalyst is required to accelerate the reaction rate at room temperature. In this work, a variety of composites are prepared from chitosan (CS) and hexagonal boron nitride (h-BN) with an ultrasonication assistance strategy for anchoring Ru nanoparticles (NPs) through an adsorption-chemical reduction approach. Benefitting from the suitable porosity (Vp = 0.123 cm3 g−1, SBET = 35.9 m2 g−1) as well as the interesting confinement and anchoring effects of CS-h-BN with an optimized CS amount of 20%, Ru/CS-h-BN with a Ru loading of 2.0 wt% shows small particle size of well-dispersed Ru NPs and the highest catalytic activity toward AB hydrolysis among the investigated catalysts. Catalyzed by Ru/CS-h-BN, the specific hydrogen evolution rate (29.9 × 103mLmin−1gRu−1) and turnover frequency (121.9 min−1) at 303 K, along with apparent activation energy (35.19 kJ mol−1) are obviously competitive compared to many Ru-based catalysts ever reported. Apart from providing a high-performance catalyst for hydrogen evolution from AB hydrolysis, our work paves a new avenue toward developing structure-sensitive nano-metal materials.

Highly sensitive detection of lead ions and cadmium ions based on ZIF-8-NH2 enhanced by carbon nanotubes and bismuth film

Heavy metal ions are common pollutants in the water environment, which have caused severe damage to the water environment, so it is necessary to monitor them. In this work, an electrochemical sensor based on aminated Zn (Ⅱ) metal-organic framework (ZIF-8-NH2) enhanced by carbon nanotubes (CNTs) and bismuth (Bi) film was prepared for simultaneous detection of lead ions (Pb2+) and cadmium ions (Cd2+) in water samples. The ZIF-8-NH2/CNTs was prepared by electrostatic assembly with ultrasonic assistance. The results show that the combination of ZIF-8-NH2 and CNTs not only can promote the three-dimensional distribution of CNTs, but also compensated for the poor electrical conductivity of ZIF-8-NH2. Furthermore, the deposition of Bi film in situ promoted the enrichment of Pb2+ and Cd2+ in the detection process, further enhancing the electrochemical signal. Based on this, the prepared sensor displayed good linear ranges of 0.050–1.000 μM (Pb2+) and 0.100–0.700 μM (Cd2+), lower detection limits of 8.00 nM (Pb2+) and 12.0 nM (Cd2+) under optimal experiment condition. At last, this sensor was successfully applied to simultaneously detect Pb2+ and Cd2+ in paddy water and lake water with recovery rates of 97.88 ∼ 104.06% and relative standard deviation (RSD) lower than 6.24%. Most importantly, there is no significant difference between the developed electrochemical method and certified method (P < 0.05). This work provides a new idea for the simultaneous detection of heavy metal ions in the water environment.

Feasibility study on multifrequency excitation of the melt pool during ultrasonic-assisted laser beam welding

The constantly increasing demands on components and their resource-efficient production require new strategies in modern process chains. The Collaborative Research Centre (CRC) 1153 “Tailored Forming” is working on the production of hybrid solid components made from joined semi-finished products with subsequent forming. Laser beam welding with ultrasonic assistance has proven to be advantageous in the production of semi-finished products due to the active influence on the microstructure as a result of the excitation. In this work, the feasibility of extending the monofrequency excitation of the melt pool used so far during welding to a multifrequency excitation is investigated. Results from simulations and experiments show that a multi-frequency excitation of the weld pool can be effectively realised. Furthermore, it is shown that a combination of previously separately used excitation methods (positioning of the melt pool in the vibration node and in the vibration antinode, respectively) with two different frequencies is successful and leads to a combination of effects as desired, what can be seen from micrographs.

Residual stresses in ultrasonic vibration assistance turning cemented carbide

Residual stresses in ultrasonic vibration assistance turning cemented carbide

Determination of Isoflavones in Radix puerariae from Different Origins by Ultra-High Performance Liquid Chromatography Based on Optimal Pretreatment Method.

A new method for simultaneous determination of puerarin, daidzin, daidzein and genistein in Radix puerariae by ultra-high performance liquid chromatography was established. The target analytes were extracted from Radix puerariae by 70% ethylene glycol with the assistance of ultrasonication, purified by the absorption of N-propyl ethylenediamine (PSA), and separated on a Supersil ODS column (4.6 mm × 250 mm × 2.5 μm). Gradient elution in 12 min was performed with the mobile phase 0.1% formic acid(A)-acetonitrile(B). The column temperature was 25 °C and the flow rate was 1 mL/min. The detection wavelength of the four target analytes was 250 nm. The limits of detection (LODs) of puerarin, daidzin, daidzein and genistein were 0.086 mg/L, 0.020 mg/L, 0.027 mg/L and 0.037 mg/L, respectively, and limits of quantitation (LOQs) were 0.29 mg/L, 0.065 mg/L, 0.090 mg/L and 0.12 mg/L, respectively. The recovery of the four substances ranged from 90.5% to 109.6%, and the relative standard deviation (n = 6) was less than 7.7%. With the established methods, puerarin, daidzin, daidzein and genistein in Radix puerariae from 11 origins were determined. The contents of the four compounds varied with the origin and variety. It provides basic data and technical means for quality control and regulation of Radix puerariae.

Simple and rapid formic acid sample treatment for the isolation of HgSe nanoparticles from animal tissues

The present work explores for the first time the potential of formic acid on the extraction of tiemannite (HgSe) nanoparticles from seabird tissues, in particular giant petrels. Mercury (Hg) is considered one of the top ten chemicals of major public health concern. However, the fate and metabolic pathways of Hg in living organisms remain unknown. Methylmercury (MeHg), largely produced by microbial activity in the aquatic ecosystems is biomagnified in the trophic web. HgSe is considered the end-product of MeHg demethylation in biota and an increasing number of studies focuses on the characterization of this solid compound to understand its biomineralization. In this study, a conventional enzymatic treatment is compared with a simpler and environmentally friendly extraction by using formic acid (5 mL of = 50 % formic acid) as exclusive reagent. The analyses by spICP-MS of the resulting extracts from a variety of seabird biological tissues (liver, kidneys, brain, muscle) reveal comparable results by both extraction approaches in terms of nanoparticles stability and extraction efficiency. Therefore, the results included in this work demonstrate the good performance of employing organic acid as simple, cost effective and green procedure to extract HgSe nanoparticles from animal tissues. Moreover, an alternative consisting of a classical enzymatic procedure but with ultrasonic assistance reducing the extraction time from 12 h to 2 min is also described for the first time. The sample processing methodologies developed, combined with spICP-MS, have emerged as powerful tools for the rapid screening and quantification of HgSe nanoparticles in animal tissues. Finally, this combination allowed us to identify the possible occurrence of Cd particles and As particles associated with HgSe NPs in seabirds.

Degradation of 1-alkyl-3-methylimidazolium tetrafluoroborate in an ultrasonic zero-valent zinc and activated carbon micro-electrolysis system

Increased attention has been given to the removal of ionic liquids (ILs) from natural water environments. In this work, 5 kinds of 1-alkyl-3-methylimidazoliumtetrafluoroborate ([Cnmim][BF4] (n = 2, 4, 6, 8, 10)) ILs were degraded in an ultrasonic zero-valent zinc (ZVZ) and activated carbon (AC) micro-electrolysis system. Optimization of degradation conditions and the degradation levels were studied by high performance liquid chromatography, the surface morphology of the ZVZ and AC changed before and after the reaction were observed by scanning electron microscope. The degradation intermediates were detected by gas chromatography- mass spectrometry and ion chromatography, and inferred the degradation pathway. The degradation effect of [C4mim][BF4] was best with ultrasonic assistance, pH 3 and an AC/ZVZ ratio of 1:1. The degradation of [Cnmim][BF4] in aqueous solution exceeded 91.7% in 120 min, and the mineralization level exceeded 88.9%. The surface of smooth and dense ZVZ particles became loose flocculent and the porous surface of AC became larger and rougher after reaction. The degradation pathway suggested that the imidazolium ring was sulfurized or oxidized, and then the ring was opened to form N-alkyl formamide and N-methyl formamide. ZVZ/AC micro-electrolysis combined with ultrasonic irradiation is an effective method to remove ILs, which provides new insight into IL degradation.

Wear resistance and friction analysis of Ti6Al4V cylindrical ball-burnished specimens with and without vibration assistance

The objective of the research is to analyze the impact of the ultrasonic vibration assistance on the wear resistance due to the topography enhancement caused on Ti6Al4V cylindrical samples after surface modification through a ball burnishing process. The process parameters considered for this study are the burnishing force, the number of passes, and the addition of a 40 kHz ultrasonic assistance, which are thought to enhance the surface topography and increase the hardener effect in terms of depth. A complete screening design of 3 factors was performed, revealing that the number of passes and the vibration assistance are the most important parameters for minimizing the wear volume loss, being 170 N of burnishing force, 3 passes, and the addition of the vibration assistance as the best combination found. However, no significant difference in the friction force was observed. The topography results show that there is a decrease in the average roughness from 1.50 to 0.45 μm with optimal burnishing conditions. It was also analyzed the microstructure originated after the turning, the conventional ball burnishing, and the vibration-assisted ball burnishing, being the last optimal in terms of depth affectation to the microstructure. Therefore, these results confirm an improvement in terms of wear enhancement, friction reduction, and topography results when vibration assistance is added to a conventional ball burnishing process.

Effect of ultrasonic vibration on residual stress in plasma cladding of iron-based alloy

To explore the effect of ultrasonic vibration power and frequency on the residual stress of single-channel iron-based alloy plasma cladding, the single-factor ultrasonic vibration plasma cladding test was designed, and ten groups of single-channel iron-based alloy cladding samples under different process parameters were studied. The drilling method was used to measure the residual stress of the substrate at the beginning, middle and tail positions of each sample cladding layer. The residual stress of the substrate was analyzed and the significant characteristics of the effect of ultrasonic vibration power and frequency on the residual stress at different positions were explored using variance analysis. The results show that the residual stress is significantly reduced after applying ultrasonic waves. When the ultrasonic frequency is constant and the ultrasonic power is 240 W, the residual stress of the formed sample is the smallest. Compared with the unapplied ultrasonic assistance, the residual stress in the X direction is reduced by 62.56%, and the residual stress in the Y direction is reduced by 63.23%. When the ultrasonic power is constant and the ultrasonic frequency is 28 kHz, the residual stress of the formed sample is the smallest. Compared with the unapplied ultrasonic assistance, the residual stress in the X direction is reduced by 17.23%, and the residual stress in the Y direction is reduced by 19.79%. The ultrasonic power significantly affects the middle part of the substrate, and the ultrasonic frequency significantly affects each point of the substrate.