Nontraditional energy-assisted mechanical machining of difficult-to-cut materials and components in aerospace community:a comparative analysis

The aerospace community widely uses difficult-to-cut materials,such as titanium alloys,high-temperature alloys,metal/ceramic/polymer matrix composites,hard and brittle materials,and geometrically complex components,such as thin-walled structures,microchannels,and complex surfaces.Mechanical machining is the main material removal process for the vast majority of aerospace components.However,many problems exist,including severe and rapid tool wear,low machining efficiency,and poor surface integrity.Nontraditional energy-assisted mechanical machining is a hybrid process that uses nontraditional energies(vibration,laser,electricity,etc)to improve the machinability of local materials and decrease the burden of mechanical machining.This provides a feasible and promising method to improve the material removal rate and surface quality,reduce process forces,and prolong tool life.However,systematic reviews of this technology are lacking with respect to the current research status and development direction.This paper reviews the recent progress in the nontraditional energy-assisted mechanical machining of difficult-to-cut materials and components in the aerospace community.In addition,this paper focuses on the processing principles,material responses under nontraditional energy,resultant forces and temperatures,material removal mechanisms,and applications of these processes,including vibration-,laser-,electric-,magnetic-,chemical-,advanced coolant-,and hybrid nontraditional energy-assisted mechanical machining.Finally,a comprehensive summary of the principles,advantages,and limitations of each hybrid process is provided,and future perspectives on forward design,device development,and sustainability of nontraditional energy-assisted mechanical machining processes are discussed.

Towards Sustainable Grinding of Difficult-to-Cut Alloys-A Holistic Review and Trends

Grinding,a critical precision machining process for difficult-to-cut alloys,has undergone continual technological advancements to improve machining efficiency.However,the sustainability of this process is gaining heightened attention due to significant challenges associated with the substantial specific grinding energy and the extensive heat generated when working with difficult-to-cut alloys,renowned for their exceptional physical and mechanical properties.In response to these challenges,the widespread application of massive coolant in manufacturing industries to dissipate grinding heat has led to complex post-cleaning and disposal processes.This,in turn,has resulted in issues such as large energy consumption,a considerable carbon footprint,and concerns related to worker health and safety,which have become the main factors that restrict the development of grinding technology.This paper provides a holistic review of sustainability in grinding difficult-to-cut alloys,encompassing current trends and future directions.The examination extends to developing grinding technologies explicitly tailored for these alloys,comprehensively evaluating their sustainability performance.Additionally,the exploration delves into innovative sustainable technologies,such as heat pipe/oscillating heat pipe grinding wheels,minimum quantity lubrication,cryogenic cooling,and others.These groundbreaking technologies aim to reduce dependence on hazardous coolants,minimizing energy and resource consumption and carbon emissions associated with coolant-related or subsequent disposal processes.The essence of these technologies lies in their potential to revolutionize traditional grinding practices,presenting environmentally friendly alternatives.Finally,future development trends and research directions are put forward to pursue the current limitation of sustainable grinding for difficult-to-cut alloys.This paper can guide future research and development efforts toward more environmentally friendly grinding operations by understanding the current state of sustainable grinding and identifying emerging trends.

Enhanced UAV Pursuit-Evasion Using Boids Modelling:A Synergistic Integration of Bird Swarm Intelligence and DRL

TheUAV pursuit-evasion problem focuses on the efficient tracking and capture of evading targets using unmanned aerial vehicles(UAVs),which is pivotal in public safety applications,particularly in scenarios involving intrusion monitoring and interception.To address the challenges of data acquisition,real-world deployment,and the limited intelligence of existing algorithms in UAV pursuit-evasion tasks,we propose an innovative swarm intelligencebased UAV pursuit-evasion control framework,namely“Boids Model-based DRL Approach for Pursuit and Escape”(Boids-PE),which synergizes the strengths of swarm intelligence from bio-inspired algorithms and deep reinforcement learning(DRL).The Boids model,which simulates collective behavior through three fundamental rules,separation,alignment,and cohesion,is adopted in our work.By integrating Boids model with the Apollonian Circles algorithm,significant improvements are achieved in capturing UAVs against simple evasion strategies.To further enhance decision-making precision,we incorporate a DRL algorithm to facilitate more accurate strategic planning.We also leverage self-play training to continuously optimize the performance of pursuit UAVs.During experimental evaluation,we meticulously designed both one-on-one and multi-to-one pursuit-evasion scenarios,customizing the state space,action space,and reward function models for each scenario.Extensive simulations,supported by the PyBullet physics engine,validate the effectiveness of our proposed method.The overall results demonstrate that Boids-PE significantly enhance the efficiency and reliability of UAV pursuit-evasion tasks,providing a practical and robust solution for the real-world application of UAV pursuit-evasion missions.

Self-Healing Liquid Metal Magnetic Hydrogels for Smart Feedback Sensors and High-Performance Electromagnetic Shielding

Hydrogels exhibit potential applications in smart wearable devices because of their exceptional sensitivity to various external stimuli.However,their applications are limited by challenges in terms of issues in biocompatibility,custom shape,and self-healing.Herein,a conductive,stretchable,adaptable,self-healing,and biocompatible liquid metal GaInSn/Ni-based composite hydrogel is developed by incorporating a magnetic liquid metal into the hydrogel framework through crosslinking polyvinyl alcohol(PVA)with sodium tetraborate.The excellent stretchability and fast self-healing capability of the PVA/liquid metal hydrogel are derived from its abundant hydrogen binding sites and liquid metal fusion.Significantly,owing to the magnetic constituent,the PVA/liquid metal hydrogel can be guided remotely using an external magnetic field to a specific position to repair the broken wires with no need for manual operation.The composite hydrogel also exhibits sensitive deformation responses and can be used as a strain sensor to monitor various body motions.Additionally,the multifunctional hydrogel displays absorption-dominated electromagnetic interference(EMI)shielding properties.The total shielding performance of the composite hydrogel increases to~62.5 dB from~31.8 dB of the pure PVA hydrogel at the thickness of 3.0 mm.The proposed bioinspired multifunctional magnetic hydrogel demonstrates substantial application potential in the field of intelligent wearable devices.

Grinding Characteristics of MoS_(2)-Coated Brazed CBN Grinding Wheels in Dry Grinding of Titanium Alloy

As an important green manufacturing process,dry grinding has problems such as high grinding temperature and insufficient cooling capacity.Aiming at the problems of sticking and burns in dry grinding of titanium alloys,grinding performance evaluation of molybdenum disulfide(MoS_(2))solid lubricant coated brazed cubic boron carbide(CBN)grinding wheel(MoS_(2)-coated CBN wheel)in dry grinding titanium alloys was carried out.The lubrication mechanism of MoS_(2)in the grinding process is analyzed,and the MoS_(2)-coated CBN wheel is prepared.The results show that the MoS_(2)solid lubricant can form a lubricating film on the ground surface and reduce the friction coefficient and grinding force.Within the experimental parameters,normal grinding force decreased by 42.5%,and tangential grinding force decreased by 28.1%.MoS_(2)lubricant can effectively improve the heat dissipation effect of titanium alloy grinding arc area.Compared with common CBN grinding wheel,MoS_(2)-coated CBN wheel has lower grinding temperature.When the grinding depth reaches 20μm,the grinding temperature decreased by 30.5%.The wear of CBN grains of grinding wheel were analyzed by mathematical statistical method.MoS_(2)lubricating coating can essentially decrease the wear of grains,reduce the adhesion of titanium alloy chip,prolong the service life of grinding wheel,and help to enhance the surface quality of workpiece.This research provides high-quality and efficient technical support for titanium alloy grinding.

A-Site Effect on the Conversion of Bio-Ethanol into Isobutene over Ternary A1ZnyZrzOn Catalysts

Ternary multifunctional A1ZnyZrzOn catalysts are prepared by introducing A-site transition metals with the redox capability into binary Zn1Zr8On. Structure and morphology were investigated by means of XRD, BET and FESEM, respectively. Activity data showed that Cr addition exhibited obvious beneficial effect to promote isobutene production from direct conversion of bio-ethanol compared to other A-site metal dopants. A significant higher yield of isobutene over Cr-promoted Zn1Zr8On catalyst was also observed with respect to its binary Zn1Zr8On counterpart. The choice of A-site metal is of prime importance in the isobutene production, catalyzing mainly the ethanol dehydrogenation, meanwhile the appropriate addition of zinc on the catalyst surface is also essential for good isobutene yield.

One-Dimensional Magnetic FeCoNi Alloy Toward Low-Frequency Electromagnetic Wave Absorption

Rational designing of one-dimensional(1D)magnetic alloy to facilitate electromagnetic(EM)wave attenuation capability in low-frequency(2-6 GHz)microwave absorption field is highly desired but remains a significant challenge.In this study,a composite EM wave absorber made of a FeCoNi medium-entropy alloy embedded in a 1D carbon matrix framework is rationally designed through an improved electrospinning method.The 1D-shaped FeCoNi alloy embedded composite demonstrates the high-density and continuous magnetic network using off-axis electronic holography technique,indicating the excellent magnetic loss ability under an external EM field.Then,the in-depth analysis shows that many factors,including 1D anisotropy and intrinsic physical features of the magnetic medium-entropy alloy,primarily contribute to the enhanced EM wave absorption performance.Therefore,the fabricated EM wave absorber shows an increasing effective absorption band of 1.3 GHz in the low-frequency electromagnetic field at an ultrathin thickness of 2 mm.Thus,this study opens up a new method for the design and preparation of high-performance 1D magnetic EM absorbers.

Layered Foam/Film Polymer Nanocomposites with Highly Efficient EMI Shielding Properties and Ultralow Reflection

Lightweight,high-efficiency and low reflection electromagnetic interference(EMI)shielding polymer composites are greatly desired for addressing the challenge of ever-increasing electromagnetic pollution.Lightweight layered foam/film PVDF nanocomposites with efficient EMI shielding effectiveness and ultralow reflection power were fabricated by physical foaming.The unique layered foam/film structure was composed of PVDF/SiCnw/MXene(Ti_(3)C_(2)Tx)composite foam as absorption layer and highly conductive PVDF/MWCNT/GnPs composite film as a reflection layer.The foam layer with numerous heterogeneous interfaces developed between the SiC nanowires(SiCnw)and 2D MXene nanosheets imparted superior EM wave attenuation capability.Furthermore,the microcellular structure effectively tuned the impedance matching and prolonged the wave propagating path by internal scattering and multiple reflections.Meanwhile,the highly conductive PVDF/MWCNT/GnPs composite(~220 S m^(−1))exhibited superior reflectivity(R)of 0.95.The tailored structure in the layered foam/film PVDF nanocomposite exhibited an EMI SE of 32.6 dB and a low reflection bandwidth of 4 GHz(R<0.1)over the Kuband(12.4-18.0 GHz)at a thickness of 1.95 mm.A peak SER of 3.1×10^(-4) dB was obtained which corresponds to only 0.0022% reflection efficiency.In consequence,this study introduces a feasible approach to develop lightweight,high-efficiency EMI shielding materials with ultralow reflection for emerging applications.

左乳腺癌保乳术后瘤床同步加量静态调强放射治疗与断层定野放射治疗的剂量学研究

目的探讨左乳腺癌保乳术后瘤床同步加量静态调强放射治疗(sIMRT)与断层定野放射治疗(TD)的剂量学特点。方法选取2016年5月-2018年5月云南省肿瘤医院左乳腺癌保乳术后瘤床银夹标记患者24例,对同一患者分别采用sIMRT计划设计(Monaco5.11.03治疗计划系统)和TD计划设计(TomoTherapy治疗计划系统),比较两种计划的剂量学参数。结果两组计划的肿瘤计划靶区(PGTV)的D_(2%)、D_(98%)、适形指数(CI)、均匀性指数(HI)比较,差异均有统计学意义(P<0.05),sIMRT的CI(0.75±0.05)高于TD的CI(0.61±0.13),TD的HI(0.04±0.01)低于sIMRT的HI(0.05±0.00)(P<0.05)。D_(50%)组间差异无统计学意义(P>0.05)。两组计划的乳腺计划靶区(PTV)的D_(98%)、CI、HI比较,差异均有统计学意义(P<0.05),sIMRT的CI(0.82±0.04)高于TD的CI(0.68±0.05),TD的HI(0.19±0.01)低于sIMRT的HI(0.20±0.01)(P<0.05),D_(2%)、D_(50%)组间差异均无统计学意义(P>0.05)。在危及器官的比较上,sIMRT较TD降低了左肺的V_(5)、V_(20)、D_(mean)以及左右心室的D_(mean)(P<0.05),其中sIMRT左肺的V_(5)、V_(20)和D_(mean)较TD分别降低了3.69%、1.26%、7.84%。TD较sIMRT降低了对侧乳腺的D_(mean)、心脏的V30、左右心房的D_(mean)及脊髓的D_(2%)(P<0.05)。但在心脏的D_(mean)方面两者组间差异无统计学意义(P>0.05)。结论sIMRT技术和TD技术均能满足左乳腺癌保乳术后放疗的剂量需求,sIMRT技术的CI优于TD技术的CI,TD技术的HI优于sIMRT技术的HI;sIMRT技术对患侧肺的保护更佳,对于有肺部基础疾病的患者,建议优先选择sIMRT技术;TD技术对心脏的保护并未体现出明显优势。

Narrow-bandwidth emissive carbon dots:A rising star in the fluorescent material family

Fluorescent carbon dots(CDs)have recently become a research hotspot in multidisciplinary fields owing to their distinctive advantages,including outstanding photoluminescence properties,high biocompatibility,low toxicity,and abundant raw materials.Among the promising CDs,narrow‐bandwidth emissive CDs with high color purity have emerged as a rising star in recent years because of their significant potential applications in bioimaging,information sensing,and photoelectric displays.In this review,the state-of-the-art advances of narrow-bandwidth emissive CDs are systematically summarized,and the factors influencing the emission bandwidth,preparation methods,and applications of narrow-bandwidth emissive CDs are described in detail.Besides,existing challenges and future perspectives for achieving high-performance narrow-bandwidth emissive CDs are also discussed.This overview paper is expected to generate more interest and promote the rapid development of this significant research area.

Modelling the annual cycle of landfast ice near Zhongshan Station,East Antarctica

A high resolution one-dimensional thermodynamic snow and ice(HIGHTSI)model was used to model the annual cycle of landfast ice mass and heat balance near Zhongshan Station,East Antarctica.The model was forced and initialized by meteorological and sea ice in situ observations from April 2015 to April 2016.HIGHTSI produced a reasonable snow and ice evolution in the validation experiments,with a negligible mean ice thickness bias of(0.003±0.06)m compared to in situ observations.To further examine the impact of different snow conditions on annual evolution of first-year ice(FYI),four sensitivity experiments with different precipitation schemes(0,half,normal,and double)were performed.The results showed that compared to the snow-free case,the insulation effect of snow cover decreased bottom freezing in the winter,leading to 15%–26%reduction of maximum ice thickness.Thick snow cover caused negative freeboard and flooding,and then snow ice formation,which contributed 12%–49%to the maximum ice thickness.In early summer,snow cover delayed the onset of ice melting for about one month,while the melting of snow cover led to the formation of superimposed ice,accounting for 5%–10%of the ice thickness.Internal ice melting was a significant contributor in summer whether snow cover existed or not,accounting for 35%–56%of the total summer ice loss.The multi-year ice(MYI)simulations suggested that when snow-covered ice persisted from FYI to the 10th MYI,winter congelation ice percentage decreased from 80%to 44%(snow ice and superimposed ice increased),while the contribution of internal ice melting in the summer decreased from 45%to 5%(bottom ice melting dominated).

The Differences between County,County-level City and Municipal District in the System of Administrative Divisions in China

Administrative division is an important means of political power reorganization and management,resource integration and optimal allocation,which profoundly shapes the spatial layout of urban development in China.To clarify and compare differences between counties,county-level cities and municipal districts is the primary premise for the study of administrative division and urban development.This paper analyzes the institutional differences between counties and county-level cities,as well as counties,county-level cities and municipal districts,from the aspects of organizational structure,urban construction planning,land management,finance,taxation and public services.The research shows that the establishment of counties,county-level cities and municipal districts adapt to different levels and stages of economic and social development,and the conversion from county to county-level city and the conversion from county(or county-level city)to municipal district are both important transformation ways to change their administrative systems,which has different management system and operation pattern.At the same time,the transformation of county-level administrative region is also a“double-edged sword”,we should think about the administrative system as a whole to decide whether it should be adjusted,and effectively respond to the actual needs of local economic and social development.

螺旋取代聚炔圆偏振发光材料研究进展

圆偏振发光(CPL)材料凭借其独特的光物理特性,在3D显示、防伪、生物成像、不对称催化等领域展现出巨大的应用潜力.通常,手性和发光组分的同时存在是实现CPL的必要条件.螺旋取代聚炔的手性放大效应赋予其强烈的光学活性,且主链的动态螺旋结构使其具有刺激响应性,因而在构筑CPL材料方面具有显著的优势.本文依据手性和发光组分之间相互作用方式的不同,系统地综述了螺旋取代聚炔CPL材料的构筑方法和手性光学性能,并介绍了其在手性传感、防伪和光电器件方面的应用.最后,探讨了该领域当前的挑战和未来的发展前景.

Construction of one-dimensional hierarchical MoS_(2)/Ni_(3)S_(2) composites with enhanced interfacial polarization and improved wideband microwave absorption

The construction of one-dimensional(1D)sulfides has attracted extensive attention for improving mi-crowave absorption(MA)performance owing to the anisotropic conductive networks.However,the syn-thesis of conductive 1D hierarchical materials with unique interfacial polarization and excellent MA prop-erties remains challenging.In this study,cable-like MoS_(2)/Ni_(3)S_(2) was synthesized by a one-step hydrother-mal strategy.The complex permittivity of the binary composites could be improved by tuning the thick-ness of the MoS_(2) coating.Importantly,the construction of heterogeneous contacts by MoS_(2) and Ni_(3)S_(2) contributed to enhanced polarization loss,and the charge distribution was validated by electron holog-raphy.The wide efficient absorption bandwidth can reach above 4.8 GHz at a thin thickness.These new discoveries shed light on novel structures for 1D sulfide materials and the design of functional core-shell composites for microwave absorption.

Surface integrity evolution during creep feed profile grinding ofγ-TiAl blade tenon

Gamma titanium-aluminum(γ-TiAl)intermetallic compounds are increasingly used in manufacturing key hot-end components(e.g.,blade tenon)in aero engines due to their high specific strength and lightweight properties.Creep feed profile grinding(CFPG)as a crucial precision process that is applied to produce the final profile of the blade tenon.However,sudden surface burns and microcracks of machined c-TiAl blade tenon often occur because of its low plasticity and high strength during grinding processes,leading to poor surface integrity.In this work,CFPG experiments based on the profile characteristics ofγ-TiAl blade tenon were performed and an associated undeformed chip thickness model considering grain–workpiece contact condition was established to explore the evolution of the surface integrity.Subsequently,the surface integrity was analyzed at different positions of the blade tenon in terms of surface roughness and morphology,metallographic structure,microhardness,and residual stress.Results show that the profile characteristics of blade tenon have a significant influence on machined surface integrity because of the thermomechanical effect at various detecting positions.The residual stress was established based on the undeformed chip thickness model considering the profile structure,with a prediction error of 10%–15%.The thermomechanical effect is more obvious at the bottom area,where the surface roughness,work hardening degree,and subsurface plastic deformation range are the largest,while the values at the bevel area are the smallest.Based on the undeformed chip thickness model,a residual stress finite element simulation was conducted by employing thermomechanical coupled effects.In addition,the error between the simulation and the experiment was between 10%–15%.Strain and strain rate equations were established through the relationship between material displacement and depth.The average strain and strain rate of the ground surface when ap is 1.0 mm are 18.8%and 33.2%larger than when ap is 0.5 mm,respectively.This study deepens the understanding of surface integrity under the influence of CFPGγ-TiAl and provides a practical reference and theoretical basis for realizing high-quality profile grinding of other complex parts.

Collaborative manufacturing technologies of structure shape and surface integrity for complex thin-walled components of aero-engine:Status,challenge and tendency

Presently,the service performance of new-generation high-tech equipment is directly affected by the manufacturing quality of complex thin-walled components.A high-efficiency and quality manufacturing of these complex thin-walled components creates a bottleneck that needs to be solved urgently in machinery manufacturing.To address this problem,the collaborative manufacturing of structure shape and surface integrity has emerged as a new process that can shorten processing cycles,improve machining qualities,and reduce costs.This paper summarises the research status on the material removal mechanism,precision control of structure shape,machined surface integrity control and intelligent process control technology of complex thin-walled components.Numerous solutions and technical approaches are then put forward to solve the critical problems in the high-performance manufacturing of complex thin-wall components.The development status,challenge and tendency of collaborative manufacturing technologies in the high-efficiency and quality manufacturing of complex thin-wall components is also discussed.

核壳结构LaOCl/LaFeO_(3)纳米纤维的阻抗匹配设计及其电磁吸波性能研究

电磁波在无线通信等领域的广泛应用导致了严重的电磁污染,迫切需要研发高性能电磁波吸收材料.本文针对吸波材料阻抗不匹配等关键问题,设计并成功制备了新型核壳LaOCl/LaFeO_(3)纳米纤维电磁波吸收剂.这种独特的一维多级结构由导电LaFeO_(3)磁性壳层和离子化合物LaOCl核层组成.基于介电-磁损耗耦合和阻抗匹配的协同作用,LaOCl/LaFeO_(3)纳米纤维在超低负载条件下(4 w t%),表现出-40.1 d B(2.0 mm)的反射损耗和6.4 GHz(2.4 mm)的有效吸收带宽.该工作提出了一种新型LaOCl/LaFeO_(3)纳米纤维吸波材料,并为阻抗匹配调控和电磁吸波性能优化开辟了新策略.

Engineering the electronic structure on MXenes via multidimensional component interlayer insertion for enhanced electromagnetic shielding

MXene-based functional electromagnetic interference(EMI)shielding films are highly desirable for mod-ern integrated electronic and telecommunication systems in aerospace,military,artificial intelligence,and smart and wearable electronics field.In this work,3D freestanding Ti_(3)C_(2)T_(x)/CNTs/Ni film assembled by 1D multi-walled carbon nanotubes(MWCNTs)/Ni and 2D Ti_(3)C_(2)T_(x)MXene sheets was synthesized by a facile vacuum filtration process.By electrostatic incorporation,hexagonal nickel plates embed on the CNTs and then the CNTs/Ni insert into the Ti_(3)C_(2)T_(x)layers to form magnetized Ti_(3)C_(2)T_(x)-based functional film with a compact and laminated structure.Due to the outstanding electron migration capacity in the highly conductive Ti_(3)C_(2)T_(x)sheet and multiple internal reflections from porous and segregated structures,the op-timized Ti_(3)C_(2)T_(x)/CNTs/Ni composite films show excellent EMI shielding effectiveness of 67.4 dB with elec-trical conductivity of 744 S cm^(-1).Surprisingly,a magnetization compensation strategy is built to boost the EMI shielding effectiveness with decreased conductivity.Meanwhile,the visual magnetic coupling phenomenon and charge distribution in the heterogeneous interfaces could be observed in the recon-structed electron holography images.Those encouraging results shed light on novel magnetized MXene-based functional films for high-performance EMI shielding.

Low-dimensional cobalt doped carbon composite towards wideband electromagnetic dissipation

Composites composed of a carbon matrix decorated with a metal or metal oxide derived from zeolitic imidazolate frameworks(ZIFs)have been widely applied as suitable electromagnetic wave absorbers due to their high porosity and controllable morphology.However,achieving ideal absorption performance remains a challenge owing to the inadequate conductivity and high density of the metal components.Therefore,a temperature-controlling treatment was employed for the bimetal ZIFs,and the corresponding derivatives exhibited an excellent dissipation ability with a minimum reflection loss value of−54.3 dB and an effective bandwidth of 7.0 GHz at a thickness of 2.4 mm,which resulted from the strong dipole polarization behavior.Furthermore,after successfully controlling the Zn/Co ratio,the attenuation capability was greatly enhanced at a thickness of 1.4 mm,with bandwidths of 13.0–18.0 GHz.Overall,this work provides an ameliorated strategy for microwave absorption performance of carbon-based materials.

Developing a novel radial ultrasonic vibration-assisted grinding device and evaluating its performance in machining PTMCs

Particle-reinforcing titanium matrix composites(PTMCs)exhibit the sharp raising applications in modern industries owing to its extraordinary physical and mechanical properties.However,the poor grindability and unstable grinding processes due to the existence of TiC particles and TiB short fibres inside PTMCs,leading to the sudden grinding burn and low material removal rate.In this work,a novel radial ultrasonic vibration-assisted grinding(RUVAG)device with a special cross structure was developed to improve machining efficiency and avoid grinding burns.Meanwhile,the resonant modal and transient dynamic characteristics of radial ultrasonic vibration system were discussed.Comparative grinding performance experiments were then conducted under the conventional grinding(CG)and RUVAG using mono-layer cubic boron nitride abrasive wheels,in views of the grinding forces and force ratio,grinding temperature,and ground surface morphology.Results show that the ultrasonic vibration direction can be transformed effectively using the special cross structure of vibration converter,and better vibration homogeneity can be obtained.RUVAG has a smaller tangential grinding force by 5.0%–17.2%than that of CG,but a higher normal grinding force of 6.5%–14.9%,owing to the periodic impact of grinding wheels.In addition,RUVAG possesses a remarkable lower grinding temperature in range of 24.2%–51.8%and a higher material removal rate by 2.8 times compared with CG,resulting from the intermittent cutting behavior between the grinding wheel and workpiece.In this case,the sudden burn can be avoided during high-speed grinding processes.Moreover,the proportion of micro-fracture defects on machined surface is slightly increased once the ultrasonic vibration mode is employed because of the periodic impact on reinforced particles,whereas the pull-out defects of reinforced particles are reduced significantly.