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

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International Journal of Extreme Manufacturing 2024年第2期6卷 190-271页

作者： Guolong Zhao Biao Zhao Wenfeng Ding Lianjia Xin Zhiwen Nian Jianhao Peng Ning He jiuhua xu College of Mechanical and Electrical Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016People’s Republic of China

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.

关键词： difficult-to-cut materials geometrically complex components nontraditional energy mechanical machining aerospace community

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Influence of alumina abrasive tool wear on ground surface characteristics and corrosion properties of K444 nickel-based superalloy

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Chinese Journal of Aeronautics 2022年第6期35卷 339-351页

作者： Min LI Jingfei YIN Linbo CHE Wenfeng DING jiuhua xu National Key Laboratory of Science and Technology on Helicopter Transmission Nanjing University of Aeronautics and AstronauticsNanjing 210016China

K444 nickel-based superalloy is an important material to manufacture the gas turbine due to its excellent mechanical properties at high temperatures and corrosion resistance.Currently,grinding is the mostly used method for the surface finish of the K444 alloy components.However,few studies worked on the effects of the abrasive tool wear on the ground surface characteristics and corrosion properties of K444 alloy.This study uses two different-type alumina abrasive tools,i.e.,white alumina(WA)and microcrystalline alumina(MA)wheels,to grind the K444 alloy.The influence of the alumina abrasive tool wear on ground surface characteristics and corrosion resistance performance are investigated.It is discovered that the MA wheel presents a slighter wheel wear and higher self-sharpening than the WA wheel.Compared to the WA wheel,the MA wheel has less material adhesion,which leads to a better surface finish.In the corrosion testing,the maximum corrosion depth is 80μm in the surface ground by the MA wheel but 100μm in the surface ground by the WA wheel,which demonstrates that the MA wheel grinding benefits the surface corrosion resistance of K444 alloy.Therefore,this study could provide a guide to selecting the abrasive tools and optimizing the grinding process of the K444 alloy.

关键词： Abrasive wheel wear Corrosion resistance Grinding K444 nickel-based superalloy Microcrystalline alumina

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Surface micro-texture on sapphire fabricated by laser ablation trajectory regulation

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Chinese Journal of Aeronautics 2022年第3期35卷 525-536页

作者： Quanli ZHANG Qiwen WANG Zhen ZHANG Yucan FU jiuhua xu College of Mechanical and Electrical Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China Jiangsu Key Laboratory of Precision and Micro-Manufacturing Technology Nanjing University of Aeronautics and AstronauticsNanjing 210016China

Fabrication of the surface micro-texture on the C-plane sapphire is undertaken by a355 nm Ultraviolet(UV)pulsed laser.The surface micro-textures of sapphire with different laser scanning line spacing ranging from 10 lm to 100 lm are obtained,where the selection range of scanning line spacing is controlled in the range of the groove width and plasma width to obtain a surface of high Peak-Valley(PV)value.A reasonable processing order is proposed to manufacture different types of surface micro-textures on sapphire by laser ablation trajectory regulation.In the multiple-passes laser ablation of sapphire by the UV nanosecond pulsed laser,the scanning lines in each direction is treated as once scanning.On this basis,the multiple processing can be carried out to avoid the influence of the subsequent scanning on the machined groove.In addition,the effect of different scanning line spacing on the PV value is quantified and different types of surface microtextures on sapphire,including the squares,the rhombuses and the hexagons,are successfully fabricated,which can be applied in the friction reduction or anti-reflection field.

关键词： Laser ablation trajectory Sapphire Scanning line spacing Surface micro-texture PV values

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

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Chinese Journal of Aeronautics 2023年第7期36卷 244-256页

作者： Biao ZHAO Bangfu WU Yansong YUE Wenfeng DING jiuhua xu Guoqiang GUO National Key Laboratory of Science and Technology on Helicopter Transmission Nanjing University of Aeronautics and AstronauticsNanjing 210016China Shanghai Spaceflight Precision Machinery Institute Shanghai 201600China

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.

关键词： Grinding force Grinding temperature Ground surface morphology Particle-reinforcing titanium matrix composites Radial ultrasonic vibrationassisted grinding

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Vibration coupling effects and machining behavior of ultrasonic vibration plate device for creep-feed grinding of Inconel 718 nickel-based superalloy

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Chinese Journal of Aeronautics 2022年第2期35卷 332-345页

作者： Yang CAO Yejun ZHU Wenfeng DING Yutong QIU Lifeng WANG jiuhua xu National Key Laboratory of Science and Technology on Helicopter Transmission Nanjing University of Aeronautics and AstronauticsNanjing 210016China College of Engineering Nanjing Agricultural UniversityNanjing 210032China College of Aerospace Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China

Ultrasonic vibration-assisted grinding(UVAG)is an effective and promising method for machining of hard-to-cut materials.This article proposed an ultrasonic vibration plate device enabling the longitudinal full-wave and transverse half-wave(L2T1)vibration mode for UVAG.The characteristics of two-dimensional coupled vibration in different directions were analyzed on the basis of apparent elastic method and finite element method.Furthermore,a correction factor was applied to correct the frequency error caused by the apparent elastic method.Finally,the comparative experiments between the conventional creep-feed grinding and UVAG of Inconel 718 nickel-based superalloy were carried out.The results indicate that the apparent elastic method with the correction factor is accurate for the design of plate device under the L2T1 vibration mode.Compared with the conventional creep-feed grinding,the UVAG causes the reduction of grinding force and the improvement of machined surface quality of Inconel 718 nickel-based superalloy.Furthermore,under the current experimental conditions,the optimal ultrasonic vibration amplitude is determined as 6μm,with which the minimum surface roughness is achieved.

关键词： Apparent elastic method Machining behavior Ultrasonic vibration-assisted grinding Ultrasonic vibration plate device Vibration coupling effects

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

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Chinese Journal of Mechanical Engineering 2023年第4期36卷 43-55页

作者： Junshuai Zhao Biao Zhao Wenfeng Ding Bangfu Wu Ming Han jiuhua xu Guoliang Liu National Key Laboratory of Science and Technology on Helicopter Transmission Nanjing University of Aeronautics and AstronauticsNanjing 210016China AECC Zhongchuan Transmission Machinery Co. LtdChangsha 410200China

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.

关键词： Titanium alloy Dry grinding MoS_(2)-coated CBN wheel Grinding wheel wear

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An investigation on adaptively machining the leading and tailing edges of an SPF/DB titanium hollow blade using free-form deformation

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Chinese Journal of Aeronautics 2018年第1期31卷 178-186页

作者： Zhengcai ZHAO jiuhua xu Yucan FU Zhiqiang LI College of Mechanical and Electrical Engineering Nanjing University of Aeronautics and Astronautics Nanjing 210016 China Beijing Aeronautics Manufacturing Technology Research Institute Beijing 100024 China

Titanium hollow blades are characterized with lightweight and high structural strength, which are widely used in advanced aircraft engines nowadays. Superplastic forming/diffusion bonding （SPF/DB） combined with numerical control （NC） milling is a major solution for manufacturing titanium hollow blades. Due to the shape deviation caused by multiple heat and pressure cycles in the SPF/DB process, it is hard to manufacture the leading and tailing edges by the milling process. This paper presents a new adaptive machining approach using free-form deformation to solve this problem. The actual SPF/DB shape of a hollow blade was firstly inspected by an on-machine measurement method. The measured point data were matched to the nominal SPF/DB shape with an improved ICP algorithm afterwards, by which the point-pairs between the measurement points and their corresponding points on the nominal SPF/DB shape were established, and the maximum modification amount of the final nominal shape was constrained. Based on the displacements between the point-pairs, an accurate FFD volume was iteratively calculated. By embedding the final nominal shape in the deformation space, a new final shape of the hollow blade was built. Finally, a series of measurement and machining tests was performed, the results of which validated the feasibility of the proposed adaptive machining approach.

关键词： Adaptive machining Blade geometry Free-form deformation Reconstruction Titanium

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Inverse identification of constitutive parameters of Ti_2AlNb intermetallic alloys based on cooperative particle swarm optimization

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Chinese Journal of Aeronautics 2018年第8期31卷 1774-1785页

作者： Linjiang HE Honghua SU jiuhua xu Liang ZHANG College of Mechanical and Electrical Engineering Nanjing University of Aeronautics and Astronautics

Ti_2AlNb intermetallic alloy is a relatively newly developed high-temperature-resistant structural material, which is expected to replace nickel-based super alloys for thermally and mechanically stressed components in aeronautic and automotive engines due to its excellent mechanical properties and high strength retention at elevated temperature. The aim of this work is to present a fast and reliable methodology of inverse identification of constitutive model parameters directly from cutting experiments. FE-machining simulations implemented with a modified Johnson-Cook（TANH） constitutive model are performed to establish the robust link between observables and constitutive parameters. A series of orthogonal cutting experiments with varied cutting parameters is carried out to allow an exact comparison to the 2 D FE-simulations. A cooperative particle swarm optimization algorithm is developed and implemented into the Matlab programs to identify the enormous constitutive parameters. Results show that the simulation observables（i.e., cutting forces, chip morphologies, cutting temperature） implemented with the identified optimal material constants have high consistency with those obtained from experiments,which illustrates that the FE-machining models using the identified parameters obtained from the proposed methodology could be predicted in a close agreement to the experiments. Considering the wide range of the applied unknown parameters number, the proposed inverse methodology of identifying constitutive equations shows excellent prospect, and it can be used for other newly developed metal materials.

关键词： Constitutive parameters Cooperative particle swarmoptimization Finite element modelling Inverse identification Ti2A1Nb intermetallic alloys

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Characteristics and evolution of ore-forming fluids of the Chongjiang copper deposit in the Gangdise porphyry copper belt, Tibet

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Journal of University of Science and Technology Beijing 2007年第2期14卷 97-102页

作者： Yuling Xie jiuhua xu Guangming Li Zhiming Yang Longsheng Yi Civil and Environmental Engineering School University of Science and Technology Beijing Beijing 100083 China Chengdu Institute of Geology and Mineral Resource Ministry of Land and Resource Chengdu 610082 China Institute of Mineral Resources China Academy of Geological Science Beijing 100037 China

Petrography, microthermometry, and scanning electron microscope/energy dispersive spectrometer （SEM/EDS） studies were performed on the fluid inclusions in the ore-beating quartz veins and quartz phenocrysts in the porphyry of the Chongjiang porphyry copper deposit. The analyses of the fluid inclusions indicate that the ore-forming fluids were exsolved from magma. They are near-saturated, supercritical, rich in volatile constituents, and have the capture temperature of 362-389℃ and salinities of 17.7wt%- 18.9wt% NaC1 eq. With the decreasing of temperature and pressure, the supercritical fluids were separated into a low salinity vapor phase and a high salinity liquid phase. During quartz-sericitization, the high salinity fluid boiled and separated into a low salinity vapor phase and a high salinity liquid phase. The high salinity inclusions that formed in the boiling process had daughter mineral melting temperatures higher than the homogenization temperatures of the vapor and liquid phases. The late fluids that are responsible for argillization are of lower temperature and salinity.

关键词： Gangdise porphyry copper belt Chongjiang copper deposit fluid inclusions ore-forming fluids

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Geochemical and geochronological studies of the Aketas granite from Fuyun County, Xinjiang: the implications of the petrogenesis and tectonic setting

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Chinese Journal Of Geochemistry 2015年第4期34卷 579-591页

作者： Xiaofeng Wei Xin Zhang jiuhua xu Rufu Ding Guorui Zhang Yong Tang University of Science and Technology Beijing Beijing Institute of Geology for Mineral Resources Key Laboratory of High-temperature and High-pressure Study of the Earth’s Interior Institute of GeochemistryChinese Academy of Sciences

As the wall rock of the Aketas gold deposit,the Aketas granite is about 45 km away from Fuyun County, Xinjiang Province. The zircon weighted mean U–Pb age of the Aketas granite is 309.0 ± 4.7 Ma, indicating that the Aketas granite was emplaced during the late Carboniferous. The Aketas granite belongs to the High-K calcalkaline series, with Si O2 content from 63.00 to 68.20 %,K2 O content from 3.06 to 4.49 % and Na2 O content from4.14 to 6.02 %. The Alkaline Ratio(AR) of the Aketas granite is high, from 1.89 to 3.47, and is 2.95 on average.The Aketas granite has lowPREE(92.42–122.73 ppm)and highPLREE/PHREE ratios(6.54–11.88). For the trace elements, the Aketas granite is enriched in LILE(Rb,U, Th, K) and incompatible elements, and marked depleted in HFSE(Nb, Ta, P, Ti). The geochemical characteristics of the Aketas granite suggest that it is a typical I-type and volcanic arc granite, and that the crystallization of clinopyroxene and hornblende is notable during the magmatic evolution. In combination with the regional tectonic studies, we propose that the emplacement of the Aketas granite implies the Altai and East Junggar area was still dominated by a subduction system at *309 Ma.

关键词：花岗岩地球化学同位素年代学富蕴县构造背景新疆高钾钙碱性系列成因

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