High-temperature Thermal Annealing Research Articles

Gradual Optimization of Molecular Aggregation and Stacking Enables Over 19% Efficiency in Binary Organic Solar Cells.

Volatile solid additive is an effective and simple strategy for morphology control in organic solar cells (OSCs). The development of environmentally friendly new additives which can also be easily removed without high-temperature thermal annealing treatment is currently a trend, and the working mechanism needs to be further studied. Herein, a highly volatile and non-halogenated solid additive 1-benzothiophene (BBT) is reported to regulate molecular aggregation and stacking of active layer components. According to the film-forming kinetics process, a momentary intermediate phase is formed during spin-coating, which slows down the film-forming process and leads to more ordered molecular stacking in the solid film after introducing solid additive BBT. Subsequently, after solvent vapor annealing (SVA) further treatment, the resultant blend films exhibit a tighter and more ordered molecular stacking. Consequently, the synergistic effect of solid additive BBT and SVA treatment can effectively control morphology of active layer and improve carrier transport characteristics, thereby enhancing the performance of OSCs. Finally, in D18-Cl:N3 system, an impressive power conversion efficiency of 19.53% is achieved. The work demonstrates that the combination of highly volatile solid additives and SVA treatment is an effective morphology control strategy, guiding the development of efficient OSCs.

Influence of high-temperature thermal annealing on paramagnetic point defects in silicon-rich silicon nitride films formed in a single-wafer-type low-pressure chemical vapor deposition reactor

The influence of high-temperature thermal annealing on silicon dangling bonds called K centers in Si-rich silicon nitride films grown in a single-wafer-type low-pressure chemical vapor deposition reactor with the SiH2Cl2-NH3 system at 750 °C has been investigated by combining thermal desorption spectroscopy (TDS), Fourier transform infrared spectroscopy-attenuated total reflection, spectroscopic ellipsometry, and electron spin resonance. In the TDS analysis, H2 desorption from the nitride films was detected above about 600 °C. It is found that thermal annealing at 750 and 900 °C caused a slight decrease in the K center density and a change in the g value of K centers, which are considered to be caused by changes in the atomic structure of the nitride films. On the other hand, thermal annealing at 1050 °C resulted in a substantial decrease in the K center density and the generation of paramagnetic defects with unprecedented characteristics. The findings in this study are expected to provide important guidelines for the design of manufacturing processes of nonvolatile memories.

Innovative fabrication of ultrasensitive and durable graphene fiber aerogel for flexible pressure sensors

Elastic graphene aerogels have promising applications in flexible pressure sensors. However, it is still difficult to prepare graphene aerogels with high sensitivity and reliable mechanical stability due to the challenge in structural regulation. This study proposes an innovative method for preparing graphene aerogel by combining wet-electrospinning and freeze-drying. The resultant is a cotton-like 3D graphene fiber aerogel (GFA) with soft exterior but firm essence. The aerogel assembled of randomly stacked 1D graphene fiber, exhibiting softness and low compressive strength, thus ensuring the highly sensitive. Furthermore, this graphene fiber possessing strong mechanical properties after high-temperature thermal annealing, guarantees the fatigue resistance and elasticity of the aerogel. Therefore, the assembled GFA-based pressure sensor is ultrasensitive with a high sensitivity of 18.55 kPa−1 and a low detection limit of 2 Pa. Additionally, it has a rapid response time of 2 ms and maintains good stability even after 3000 cycles. The exceptional properties of GFA suggest its immense potential for application in human health monitoring and motion detection. In addition, the wet-electrospinning preparation of GFA provides a new strategy for the fabrication of graphene aerogels.

Low-temperature decomposable industrial surfactant for stabilization of few-layered graphene in water

Surface-active agents, such as surfactant molecules, are essential for stabilizing liquid-exfoliated graphene and other 2D nanosheets in water through electrostatic or steric repulsion. It is important to note that surfactants are no longer necessary for solutions converted into thin films for electronic devices, sensors, and composite applications. High-temperature (∼400–500 °C) thermal annealing is one of the performed methods to remove surfactant molecules. However, the surfactant residues present on the graphene nanosheets by post-annealing may adversely impact the electronic properties of the graphene film, potentially resulting in additional doping and defects. To address this challenge, we report a low-temperature decomposable (∼320 °C), eco-friendly and industrially viable surfactant, i.e., coco-glucoside, for the efficient liquid-phase exfoliation and stabilization of graphene nanosheets in water. Compared with the well-studied surfactants in liquid exfoliation such as sodium dodecyl benzene sulphonate (SDBS) and sodium cholate (SC), ∼90 % of this surfactant molecules completely decomposed at ∼320 °C in an air atmosphere for coco-glucoside. Electrical conductivity studies suggested that annealing at 320 °C enhanced the conductivity by 15 times for the coco glucoside-stabilized graphene film; however, marginal change in the conductivity was observed for the SDBS and SC-stabilized graphene film. To demonstrate the viability of the concept, a wallpaper-based rapid fire alarm application utilizing coco glucoside-stabilized graphene/cellulose paper was demonstrated.

Reversing relaxation-induced embrittlement by high-temperature thermal cyclic annealing in Zr-based metallic glass

Annealing usually induces structural relaxation and reduction of liquid-like regions, leading to embrittlement in bulk metallic glasses (BMGs). Here, we find that the short-term high-temperature thermal cycling (HTC) annealed Zr41.2Ti13.8Cu12.5Ni10Be22.5 (Vit1) BMG shows an improved plasticity without sacrificing their yield strength. And only relaxation behavior with increased hardness is observed after HTC, which is different from the rejuvenation effect usually observed in cryogenic thermal cycling (CTC). We revealed that this embrittlement reversal is attributed to enhanced fluctuations of full width at half maximum (FWHM) of the hardness’ distribution at micrometer and larger scales induced by short-term HTC. The enhanced fluctuations of mechanical heterogeneities across the diameter on a cross-section of the short-term HTC sample may increase the number and decrease the size of shear transformation zones (STZs) activated at high stress and promote the deflection of shear bands (SBs) during their propagation to form multiple SBs. The enhanced plasticity after HTC induced relaxation contradicts the common sense that relaxation accompanying with annihilation of free volume or liquid-like region usually causes embrittlement. Present results indicate that short-term HTC could be a powerful mean to tune the mechanical performance, shedding new lights on the interplay among relaxation, mechanical/structural heterogeneity, and plasticity of MGs.

Efficient organic solar cells enabled by sustainable and synergetic device engineering

In order to accelerate the transfer of organic solar cells (OSCs) from lab to fab, this work develops a synergetic strategy by integrating low-cost material, green solvent, bio-based additive and low-temperature post-treatment to sustainably fabricate OSCs. The donor polymer PTQ10 composing of simple building blocks, accompanied by the acceptor L8-BO, is dissolved in the green solvent tetrahydrofuran, wherein a bio-based cinnamonitrile is firstly used as solvent additive. Moreover, fluorous solvent soaking (FSS) is employed as post-treatment to replace the high-temperature and time-consuming thermal annealing. Systematic investigations are performed to unravel the mechanism of the device engineering developed in this work. Differing from the one-way movement of additive, the fluorous solvent can penetrate into and come out the film in cycles. Meanwhile, some L8-BO is selectively dissolved and brought out by the fluorous solvent, so this partial L8-BO bears the function as solid additive to optimize the morphology. As a result, the device achieves a remarkable power conversion efficiency of 17.11%, among the best efficiencies of OSCs prepared by non-halogenated non-aromatic solvents. In addition, the excellent universality ensures this strategy is also effective in the thick-film OSCs.

Investigation of thermal annealing on the characteristics of ScxAl1−xN thin films

Good temperature stability is essential for radio-frequency (RF) devices working at high frequencies. AlN and Sc doped AlN (ScxAl1−xN) are widely used as piezoelectric thin films for their excellent performance, but the temperature characteristics of these two materials could be more precise. In this work, the effect of high-temperature thermal annealing on the characteristics of ScxAl1−xN thin films was investigated. ScxAl1−xN thin films with different Sc compositions were deposited and then annealed in different atmospheres at various temperatures. It was found that ScxAl1−xN thin films could maintain good temperature stability below 900 °C in vacuum or air, and AlN can even maintain up to 1300 °C under vacuum. When the annealing temperature exceeded 900 °C, the films’ crystallinity and lattice would appear to have apparent changes. Moreover, the introduction of oxygen at elevated temperatures could impair the surface morphologies and mechanical properties of the ScxAl1−xN thin films. The results revealed that the increased Sc composition decreased the temperature stability of the ScxAl1−xN thin films, and AlN was proved to have better temperature stability than the other two thin films. This work establishes a research foundation for utilizing ScxAl1−xN thin films in high-temperature applications.

Achieving efficient flexible and large-area organic solar cells via additive-assisted fluorous solvent soaking

Developing flexible and large-area organic solar cells (OSCs) is of vital importance for advancing the commercialization. However, using solvent additives during the film deposition is tricky and unpredictable for the large-area device. Furthermore, typical post-treatments like high-temperature thermal annealing might cause the undesired deformation of the flexible substrate, thus adversely affecting the photovoltaic performance. Herein, a new device engineering namely additive-assisted fluorous solvent soaking (AFSS), is developed as an alternative approach for OSCs fabrication. No solvent additive is used in the active layer deposition, providing more uniform films in large-area processing. The fresh-made film is subsequently soaked in a mixture of fluorous solvent and a tiny amount of solvent additive, wherein the cyclic movement of the fluorous solvent associated with the additive could facilitate the molecular reorganization at relatively low temperature (40 °C), and thus optimizing the morphology of the active layer. Compared with the traditional method, AFSS is more effective in various OSCs including the rigid or flexible substrates and the conventional or inverted device architectures. An ultra-flexible and large-area device fabricated by AFSS realizes a PCE of 12.63%. This work provides a robust and practical strategy to fabricate OSCs as well as other optoelectronic devices at low temperature.

Crack healing behavior of 4H-SiC: Effect of dopants

We investigate the crack-healing mechanism of 4H silicon carbide (4H-SiC) and reveal the effect of dopants on the crack-healing behavior of 4H-SiC. Vickers indentation tests and thermal annealing are utilized to generate cracks and heal cracks in 4H-SiC, respectively. High-temperature thermal annealing in the air atmosphere is found to be capable of effectively healing indentation-induced cracks and releasing indentation-induced stress in undoped 4H-SiC by the formation and viscous flow of glass phase SiO2. Nitrogen (N) doping is found to assist the atomic diffusion of 4H-SiC. The crack healing of N-doped 4H-SiC is realized by the synergy of host solid diffusion and the padding of glassy SiO2. In contrast, vanadium (V) doping hinders the viscous flow of SiO2 and results in the incomplete healing of cracks in V-doped 4H-SiC. Although the generation of cracks lowers the bending strength of 4H-SiC, the healing of cracks by the padding of glassy SiO2 is found to effectively recover the bending strength of indented 4H-SiC samples. Our work opens a pathway to design thermal processing technologies to heal the cracks and enhance the mechanical properties of 4H-SiC wafers.

Wet-Oxidation-Assisted Chemical Mechanical Polishing and High-Temperature Thermal Annealing for Low-Loss 4H-SiC Integrated Photonic Devices

Wet-Oxidation-Assisted Chemical Mechanical Polishing and High-Temperature Thermal Annealing for Low-Loss 4H-SiC Integrated Photonic Devices

Wet-Oxidation-Assisted Chemical Mechanical Polishing and High-Temperature Thermal Annealing for Low-Loss 4H-SiC Integrated Photonic Devices

Silicon carbide (SiC) has become a promising optical material for quantum photonics and nonlinear photonics during the past decade. In this work, we propose two methods to improve the 4H-SiC thin film quality for SiC integrated photonic chips. Firstly, we develop a wet-oxidation-assisted chemical mechanical polishing (CMP) process for 4H-SiC, which can significantly decrease the surface roughness from 3.67 nm to 0.15 nm, thus mitigating the light scattering loss. Secondly, we find that the thermal annealing of the 4H-SiC devices at 1300 °C can help to decrease the material absorption loss. We experimentally demonstrate that the wet-oxidation-assisted CMP and the high-temperature annealing can effectively increase the intrinsic quality factor of the 4H-SiC optical microring resonators.

Mechanics of Defects in Dislocation-Free Silicon Single Crystals

The problems of defect mechanics in dislocation-free silicon single crystals are relevant and technically significant due to the intensive development of microelectronics, which imposes increasingly high demands on minimizing the level of micro- and nanodefects in silicon wafers used to manufacture microelectronic chips. The solution of these problems is associated with the study of the regularities of thermomechanical processes both at the stage of growing silicon single crystals and at subsequent thermal annealing of wafers cut from them. The article provides an overview of theoretical and experimental work aimed at developing ways to control these processes. This includes the development of physical concepts of defect formation in dislocation-free single-crystal silicon and the development of mathematical models corresponding to different temperature ranges, implemented both during the growth of a single crystal and during thermal annealing of wafers cut from it. Thus, near the crystallization temperature, the processes of fast recombination and diffusion transfer of intrinsic point defects (vacancies and interstitial silicon atoms) are simulated, while at lower temperatures, the processes of their agglomeration into microdefects (pores and clusters of interstitial silicon atoms) are simulated. The verification of such models is illustrated for two experimental processes of growing silicon single crystals with a diameter of 150 mm by the Czochralski method, as well as for the process of rapid high-temperature thermal annealing of silicon wafers cut on their basis.

Fabrication of BN aerogels/Bi2Te3 composite thermoelectric generator (TEG) with high seebeck coefficient

Boron nitride (BN) aerogels materials have low density characteristics and stable three-dimensional network structure, which can be used as high thermal conductivity ultralight materials or thermal conductive polymer additives. The hexagonal boron nitride nanoribbons (BNNRs) aerogels material not only has a three-dimensional network structure with high specific surface area, but also has a two-dimensional band structure. It has ultra-low thermal conductivity along the in-plane direction, and has ultra-high aspect ratio and electrical insulation energy. However, the research on the thermoelectric properties of BN Aerogels and its composites is still blank. Therefore, it is of great significance to carry out the research on BN Aerogels, its thermoelectric composites, thermoelectric properties and the design of thermoelectric devices. In this paper, BN Aerogels were prepared by the combination of freeze-drying and high temperature thermal annealing, and the effects of 2-methyl-2-propanol (TBA) modification on the yield and quality of BN Aerogels were investigated. The experimental results show that TBA greatly reduces the width and thickness of BNNRs in BN Aerogels, and increases the aspect ratio of BNNRs. The composite thermoelectric particles were prepared by hot pressing to combine BN Aerogels and Bi2Te3 and the influence of the doping concentration of BN Aerogels on the thermoelectric parameters such as Seebeck coefficient and power factor of the thermoelectric battery was studied. The experimental results reveal that when the concentration of BN Aerogels is 1.48 wt%, the ZT value of BN Aerogels/p-Bi2Te3 composite thermoelectric particles is 0.719, while when the doping concentration of BN Aerogels is 1.96 wt%, the ZT value of BN Aerogels/n-Bi2Te3 composite thermoelectric particles is 0.577. And the TBA modified BN Aerogels/Bi2Te3 composite thermoelectric particles show that when the TBA doping concentration is 19.35 wt%, the ZT value of the TBA modified BN Aerogels/p-Bi2Te3 composite thermoelectric particles can reach 0.87, which is higher than that of BN aerogels/p-Bi2Te3 thermoelectric particles, and also much higher than that of the intrinsic p-Bi2Te3 thermoelectric particles. When the TBA doping concentration is 28.57 wt%, the ZT value of the BN Aerogels/n-Bi2Te3composite thermoelectric particles modified by TBA can reach 0.623, which is also higher than that of the BN aerogels/n-Bi2Te3 thermoelectric particles, and also much higher than that of the intrinsic n-Bi2Te3 thermoelectric particles. And based on the self-prepared TBA modified BN Aerogels/Bi2Te3 composite thermoelectric particles, the TEG thermoelectric battery was designed and manufactured. The Seebeck coefficient of the TEG thermoelectric battery can be reached 886.08 μV/K, the conductivity can be reached 9.74 × 104 S/m, and the thermoelectric power factor and power density are 7.65 × 104 μW/mK2 and 14.49 μW/cm3, respectively. This system reduces the need for physical space by using a common framework, which is conducive to the application of thermoelectric power generation technology in micro and small fields.

Preparation of oriented poly(lactic acid) thin films by a combination of high temperature rubbing and thermal annealing: Impact of annealing parameters on structure, polymorphism and morphology

AbstractHigh temperature rubbing is a fast and low‐cost method to prepare highly oriented films of polymers. This contribution describes the fabrication of smooth and pin‐hole‐free poly(lactic acid) (PLA) thin films of controlled structure and morphology using a combination of rubbing at moderate temperature (T ≤ 100°C) and thermal annealing. We investigate the impact of annealing temperature and duration on the structure of rubbed PLLA and stereo‐complex (SC) thin films. The importance of annealing parameters on polymorphism, crystallinity, crystal dimensions and in‐plane orientation are analyzed using Transmission Electron Microscopy, Differential Scanning Calorimetry and FTIR spectroscopy. Regarding SC PLA films, the conditions are identified to fully transform the equimolar PLLA‐PDLA blend films into pure oriented SC films without presence of homocrystals.

Commonality of structural transformations in LiF and MgF2 ionic crystals with Co and Ni impurities and metal crystals with metal impurities during heat treatment

The processes of formation of nickel and cobalt containing films on the surface of LiF:Co, LiF:Ni and MgF2:Co, MgF2:Ni single crystals due to high-temperature thermal annealing have been studied for the first time. The purpose of research was finding out the possibility of obtaining nanoscale metal containing films by intracrystalline diffusion of metal impurity from inside the ionic crystal to the surface. Methods of formation and properties of Ni and Co containing films on the ionic crystals is important due to the possibility of their application in optoelectronic devices, spintronics, for recording information with used of film as optical and magnetic media and in other fields. Thermal etching at 750–900 °C was carried out in vacuum and in air. The analysis of the surface of samples was carried out using an electron-ion scanning microscope. Elemental analysis of samples surface was carried out by mapping surface elements and at individual points. It was determined that impurities come out of dislocations in crystals and form metal containing film on the surface. The films contain predominantly Ni, Co, and O elements, as well as elements of the film interaction with air atmosphere. The value of the film thickness is estimated as lying in the range from 0.5 to 5.0 μm. After release of impurity from crystal dislocations, thermal etching pits of various shapes remain. An analogy is drawn between the processes of thermal etching of ionic crystals studied by us and metallic crystalline materials analyzed from scientific literature. General regularities are revealed and differences between two types of crystalline matrices due to high-temperature thermal annealing are noted.

Microstructural changes in nuclear graphite induced by thermal annealing

Irradiation-induced property change in nuclear graphite is particularly important when considering the in-service lifetimes of graphite components. In other works, it has been shown that annealing of irradiated graphite above the irradiation temperature may heal atomic-level defects and thus reverse some amount of physical property change. In this work, virgin nuclear graphite IG-110 was annealed at 2500 °C to observe any microstructural changes due solely to high-temperature thermal annealing. The results shown in this study suggest that fullerene-like defects, which are not observed in as-prepared nuclear graphites, will arise due to thermal annealing near graphitization temperature. Consequently, such defects may directly contribute to non -recoverable physical property change which has previously been observed in irradiated nuclear graphites. • Non-recoverable physical property changes to nuclear graphite. • High-temperature thermal annealing of nuclear graphite. • Microstructural changes induced solely by high-temperature thermal annealing. • Fullerene-like defects characterized via transmission electron microscopy.

Easy, Fast Self-Heating Polyurethane Nanocomposite with the Introduction of Thermally Annealed Carbon Nanotubes Using Near-Infrared Lased Irradiation

In this study, high-crystallinity single walled carbon nanotubes (H-SWNTs) were prepared by high-temperature thermal annealing at 1800 °C and a self-heating shape memory polyurethane nanocomposite with excellent self-heating characteristics was developed within a few seconds by irradiation with near-infrared rays. With a simple method (heat treatment), impurities at the surface of H-SWNTs were removed and at the same time the amorphous structure converted into a crystalline structure, improving crystallinity. Therefore, high conductivity (electric, thermal) and interfacial affinity with PU were increased, resulting in improved mechanical, thermal and electric properties. The electrical conductivity of neat polyurethane was enhanced from ~10-11 S/cm to 4.72 × 10-8 S/cm, 1.07 × 10-6 and 4.66 × 10-6 S/cm, while the thermal conductivity was enhanced up to 60% from 0.21 W/mK, 0.265 W/mK and 0.338 W/mK for the composites of 1, 3 and 5 wt%, respectively. Further, to achieve an effective photothermal effect, H-SWNTs were selected as nanofillers to reduce energy loss while increasing light-absorption efficiency. Thereafter, near-infrared rays of 818 nm were directly irradiated onto the nanocomposite film to induce photothermal properties arising from the local surface plasmon resonance effect on the CNT surface. A self-heating shape memory composite material that rapidly heated to 270 °C within 1 min was developed, even when only 3 wt.% of H-SWNTs were added. The results of this study can be used to guide the development of heat-generating coating materials and de-icing materials for the wing and body structures of automobiles or airplanes, depending on the molding method.

Study on Preparing β-Ga2O3 Films with Temperature-Controlled Buffer Layer by RF Magnetron Sputtering

β-Ga2O3 thin films were prepared on (0006) sapphire substrates by RF magnetron sputtering. Under the conditions of sputtering power of 80 W, time of 10 min, and total flow rate of 40 sccm in oxygen and argon atmosphere (2.5 % oxygen ratio). Different preparation temperatures were used to conduct layering by temperature modulation. A homogenous β-Ga2O3 buffer layer was grown first, and then the second β-Ga2O3 film was grown on top of it. When the stratified sputtering of different temperature combinations was completed, high-temperature thermal annealing with the same parameters was performed. The effects on the structure, surface morphology, and optical properties of β-Ga2O3 thin films were compared and analyzed when using the preparation sequence of the homogenous buffer layer and the top layer at different temperatures after annealing. Finally, based on the stratified preparation temperature parameters, the optimal stratified temperature parameters were summarized.

Synthesis of Co3O4@TiO2 catalysts for oxygen evolution and oxygen reduction reactions

The electrospinning method combined with high temperature thermal annealing was used to prepare TiO 2 fibers modified with different concentrations of Co 3 O 4 . Field emission scanning electron microscope (FESEM), transmission electron microscope (TEM), desktop scanning electron microscope (TM3030)-energy spectrometer (SwiftED3000), thermal analyzer (TGA), X-ray diffractometer (XRD), X-ray photoelectron energy Spectral analyzer (XPS), Brunauer–Emmett–Teller (BET) (BET) were used to study the influence of different cobalt oxide concentrations on the morphology of mesoporous TiO 2 fibers. Cyclic voltammetry (CV), linear sweep voltammetry (LSV), electrochemical impedance spectroscopy (EIS) and continuous cycle method were used to evaluate the fiber's oxygen evolution reaction (OER) and oxygen reduction (ORR) reactivity. It was found that the fiber with a molar ratio of Co to Ti of 1:10 showed the best performance for both OER and ORR reactions in alkaline solution. The fiber showed an overpotential of 382 mV at a current density of 10 mA cm −2 , a Tafel slope of 58 mV·dec −1 , and a half-wave potential change of only 10 mV after 4000 CV cycles. It has an onset potential of 0.83 V (vs RHE) in the ORR reaction. The OER/ORR overpotential gap (E) of 0.85 V is significantly lower than commercial platinum/carbon and bulk TiO 2 analogs. Obviously, this catalytic activity stems from the synergy between Co 3 O 4 and TiO 2 fibers. In addition, the higher specific surface area and the presence of disordered mesopores provide a higher charge carrier density during the electrocatalytic process, which improves the reaction activity. • TiO 2 was adopted in present research to replace carbon as a catalyst support substrate. • The Co 3 O 4 @TiO 2 nanofiber possess an unique mesoporous structure, which provides more active sites for the reaction, and makes good catalytic performance for the reaction through the synergistic of TiO 2 and Co 3 O 4 . • The Co 3 O 4 @TiO 2 nanofibers show good catalytic performance for both the OERand ORR.

An investigation on microstructure and mechanical properties of 316 stainless steel: a comparison between ultrasonic treatment and thermal annealing

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