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Journal of Materiomics 2024年第3期10卷 652-669页

作者： Jiageng xu Shaoxiong Xie Qian xu Jie Xing Qingyuan wang Jianguo zhu School of aeronautics and astronautics Sichuan UniversityChengdu610000China Institute for Advanced Study Chengdu UniversityChengdu610106China Department of mechanical engineering Kyushu UniversityFukuoka819-0395Japan college of Architecture and Environment Sichuan UniversityChengdu610065China college of Material Science and engineering Sichuan UniversityChengdu610065China

With the rapid development of high-end industries,the demand for high-temperature piezoelectric materials is significantly ***,realizing the ultra-high performance to meet more ap-plications still faces major scientific and engineering challenges of our ***,a new Nb/Mn co-doped CaBi_(4)Ti_(4)O_(15)(CBT)high-temperature piezoelectric material system of CaBi_(4)Ti_(4-x)(Nb_(2/3)Mn_(1/3))_(x)O_(15)was synthesized by the conventional solid-state sintering *** results show that the addition of the dopants tends to break the long-range ferroelectric chain and soften the flexibility of polarization,resulting in more distorted crystal structure and better ferroelectric properties of CBT *** ultra-high piezoelectric constant(d_(33)=26.8 pC/N)is thus attained in CBT-based ceramics with x=0.12,which is about several times larger than that of pure CBT ***,numerous nano-sized layered domain structures that lie on the lateral plane of grains are observed in ceramics,with lower domain wall energy and better dynamic features under electric fields,mainly responsible for the origin of enhanced ***,excess dopants could make the conductivity mechanism of CBT ceramics transform from p-type to n-type,and also result in a shift of conduction relaxation mechanism from defect dipole rotation polarization to electron relaxation *** work not only provides a promising candidate for high-temperature piezoelectric materials,but also opens a window for opti-mizing performance by tailoring domain structures using chemical modification.

关键词： CaBi_(4)Ti_(4)O_(15) Lattice distortion electrical performance Domain structure Conductivity mechanism

makeTwin:A reference architecture for digital twin software platform

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Chinese Journal of aeronautics 2024年第1期37卷 1-18页

作者： Fei TAO xuemin SUN Jiangfeng CHENG Yonghuai zhu Weiran LIU Yong wang Hui xu Tianliang HU Xiaojun LIU Tingyu LIU Zheng SUN Jun xu Jinsong BAO Feng XIANG Xiaohui JIN digital Twin International Research Center International Research Institute for Multidisciplinary ScienceBeihang UniversityBeijing 100191China School of Automation Science and electrical engineering Beihang UniversityBeijing 100191China Institute of Advanced Manufacturing and Intelligent Technology Beijing University of TechnologyBeijing 100124China RIAMB(Beijing)Technology Development Co Ltd(R.T.D.)Beijing 100120China School of mechanical engineering Shandong UniversityJinan 250061China School of mechanical engineering Southeast UniversityNanjing 211189China School of mechanical engineering Xi’an Jiaotong UniversityXi’an 710049China college of mechanical engineering Donghua UniversityShanghai 201620China School of Machinery and Automation Wuhan University of Science and TechnologyWuhan 430081China Beijing Aero-top Hi-tech Co LtdBeijing 100176China

digital twin is currently undergoing a significant transformation from the conceptual and theoretical research phase to the implementation and application ***,a universally adaptable research and development platform for digital twin is critically needed to meet the development ***,a publicly accessible simulation,testing,and validation platform which can support digital twin model building,data processing,algorithm design,configuration,etc.,is urgently required for ***,for developers from the industry,a lowcode development platform that can offer a customizable suite of functions such as model creation,data management,protocol configuration,and visualization is urgently ***,for enterprise users,there is a lack of an application management platform that can be configured and migrated for various application scenarios,functions,and ***,based on the system research of digital twin theories and key technologies by the authors(such as the five-dimension digital twin model,digital twin modeling and digital twin data theory,digital twin standards,and so on),a digital twin software platform reference architecture,namely make Twin,is proposed and designed,as well as its ten core *** workflow of the make Twin and the interaction mechanisms among its core functions are ***,a digital twin application system for a chemical fiber textile shop floor(CFTS)which was developed according to make Twin,is introduced,which validates the proposed reference architecture.

关键词： digital twin digital twin software platform Industrial software makeTwin Reference architecture

Improving profile accuracy and surface quality of blisk by electrochemical machining with a micro inter-electrode gap

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Chinese Journal of aeronautics 2023年第4期36卷 523-537页

作者： Jingtao wang zhengyang xu di zhu college of mechanical and electrical engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China

Electrochemical machining(ECM)has emerged as an important option for manufacturing the *** inter-electrode gap(IEG)distribution is an essential parameter for the blisk precise shap-ing process in ECM,as it affects the process stability,profile accuracy and surface *** IEG leads to a poor localization effect and has an adverse influence on the machining accuracy and surface quality of *** achieve micro-IEG(shing machining,this work puts forward a novel variable-parameters blisk ECM strategy based on the synchronous coupling mode of micro-vibration amplitude and small pulse *** modelling and simulation of the blisk micro-IEG machining have been carried *** experiments of variable-parameters blisk ECM were car-ried *** results illustrated that the IEG width reduced with the progress of variable parameter *** IEG width of the blade’s concave part and convex part could be successfully controlled to within 30 lm and 21 lm,*** profile deviation for the blade’s concave surface and convex surface are 49 lm and 35 lm,while the surface roughness reaches R_(a)=0.149 lm and R_(a)=0.196 lm,*** profile accuracy of the blisk leading/trailing edges was limited to within 91 ***-pared with the currently-established process,the profile accuracy of the blade’s concave and convex profiles was improved by 50.5%and 53.3%,*** surface quality was improved by 53.2%and 50.9%,***,the machined surface was covered with small corrosion pits and weak attacks of the grain boundary due to selective *** electrolytic products were dispersed on the machined surface,and their components were mainly composed of the carbide and oxide products of Ti and Nb *** results indicate that the variable-parameters strategy is effective for achieving a tiny IEG in blisk ECM,which can be used in engineering practice.

关键词： Electrochemical machining Blisk IEG Machining quality Surface quality

Dependency of the pulsed electrochemical machining characteristics of Inconel 718 in NaNO_(3)solution on the pulse current

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Science china(Technological Sciences) 2022年第10期65卷 2485-2502页

作者： wang JingTao xu zhengyang GENG TianYu zhu di college of mechanical and electrical engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China

Pulsed electrochemical machining(PECM)has attracted increasing interest as a technique to improve material dissolution localization and surface *** work systematically investigates the effects of pulse current on the surface morphology,profile accuracy,and corrosion behavior of Inconel 718(IN718)in NaNO_(3)*** behavior reveals that IN718 in NaNO_(3)solution during pulse current machining exhibited significant passive,transpassive,and re-passive *** passive film generated at the re-passive state contained some oxides and had a loose porous *** critical value for the quantity of electric charge to rupture the passive film was determined to be 26.88℃cm^(−2).The current efficiency indicates that the material removal rate of IN718 in NaNO_(3)solution during pulse current machining was *** PECM experiments indicate that the loading process of the electrical double layer was prolonged with an increased workpiece scale,i.e.,the loading process of the electrical double layer lasted for the entire pulse-on time when the workpiece scale was 100 mm^(2)at a frequency of more than 10 kHz regardless of the duty cycle.A pulse current with a short pulse length and short pulse period improved the profile accuracy,as did the low applied voltage and small workpiece *** dissolution mechanism of IN718 in NaNO_(3)solution was also investigated based on the effective pulse current ***,the leading-edge structure of a ruled blade with good dimensional accuracy and surface quality was successfully *** maximum deviations of the machined profile were effectively restricted within 0.057 mm,and the surface roughness was Ra=0.358μm.

关键词： pulsed electrochemical machining corrosion behavior current efficiency blade leading edge machining quality

Trajectory control strategy of cathodes in blisk electrochemical machining

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Chinese Journal of aeronautics 2013年第4期26卷 1064-1070页

作者： zhu Dong zhu di xu zhengyang Zhou Laishui college of mechanical and electrical engineering Nanjing University of Aeronautics and Astronautics State Key Laboratory of mechanical System and Vibration Shanghai Jiao Tong University

A turbine blisk, which combines blades and a disk together, is one of the most important components of an aero engine. In the process of blisk electrochemical machining （ECM）, the sheet cathode, which is usually used as a tool electrode, has a complicated structure. In addition to that, the channel between the adjacent blades is narrow and twisted, so interference is apt to happen when the sheet cathode feeds into the channel. Therefore, it is important to choose suitable trajectory control strategy. In this paper, a new trajectory control strategy of the sheet cathode is presented and corresponding simulation analysis is conducted on the basis of an actual blisk model. The simulation results demonstrate that the sheet cathode can feed into the channel by a spatial line trajectory without interference. Moreover, the verification experiments are carried out according to the simulation. The experimental results show that the cathode can move into the channel without interference. It is verified that the new trajectory control strategy is correct and can be used in the blisk ECM process successfully.

关键词： Blisk Cathodes Electrochemical machining Feed Trajectory control

Machining of a film-cooling hole in a single-crystal superalloy by high-speed electrochemical discharge drilling

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Chinese Journal of aeronautics 2016年第2期29卷 560-570页

作者： Zhang Yan xu zhengyang zhu Yun zhu di college of mechanical and electrical engineering Nanjing University of Aeronautics & Astronautics

Single-crystal superalloys are typical advanced materials used for manufacturing aero- engine turbine blades. Their unique characteristics of high hardness and strength make them exceedingly difficult to machine. However, a key structure of a turbine blade, the film-cooling hole, needs to be machined in a single-crystal superalloy; such machining is challenging, especially considering the increasing levels of machining efficiency and quality demanded by the aeroengine industry. Tube electrode high-speed electrochemical discharge drilling （TSECDD）, a hybrid technique of high-speed electrical discharge drilling and electrochemical machining, provides high machining efficiency and accuracy, as well as eliminating the recast layer. In this study, TSECDD is used to machine a film-cooling hole in a nickel-based single-crystal superalloy （DD6）. The Tagu- chi methods of experiment are used to optimise the machining parameters. Experimental results show that TSECDD can effectively drill the film-cooling hole; the optimum parameters that give the best performance are as follows： pulse duration： 12μs, pulse interval： 30 gs, peak current： 6 A, and salt solution conductivity： 3 mS/cm. Finally, a hole is machined by TSECDD, and the results are compared with those obtained by electrical discharge machining. TSECDD is found to be promising for improving the surface quality and eliminating the recast layer.

关键词： electrical discharge machin-ing (EDM) Electrochemical machining(ECM) Film-cooling hole Hybrid technique Single crystal Taguchi methods

Effect of tube-electrode inner diameter on electrochemical discharge machining of nickel-based superalloy

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Chinese Journal of aeronautics 2016年第4期29卷 1103-1110页

作者： Zhang Yan xu zhengyang Xing Jun zhu di college of mechanical and electrical engineering Nanjing University of Aeronautics & Astronautics

Nickel-based superalloys are widely employed in modern aircraft engines because of their excellent material characteristics, particularly in the fabrication of film cooling holes. However, the high machining requirement of a large number of film cooling holes can be extremely challenging. The hybrid machining technique of tube electrode high-speed electrochemical discharge drilling (TEHECDD) has been considered as a promising method for the production of film cooling holes. Compared with any single machining process, this hybrid technique requires the removal of more complex machining by-products, including debris produced in the electrical discharge machining process and hydroxide and bubbles generated in the electrochemical machining process. These by-products significantly affect the machining efficiency and surface quality of the machined products. In this study, tube electrodes in different inner diameters are designed and fabricated, and the effects of inner diameter on the machining efficiency and surface quality of TEHECDD are investigated. The results show that larger inner diameters could effectively improve the flushing condition and facilitate the removal of machining by-products. Therefore, higher material removal efficiency, surface quality, and electrode wear rate could be achieved by increasing the inner diameter of the tube electrode. (C) 2015 The Authors. Production and hosting by Elsevier Ltd. on behalf of Chinese Society of aeronautics and astronautics.

关键词： electrical discharge machining Electrochemical machining Film-cooling hole Inner diameter Nickel-based superalloys Tube electrode

Experimental research on electrochemical machining of titanium alloy Ti60 for a blisk

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Chinese Journal of aeronautics 2016年第1期29卷 274-282页

作者： Chen xuezhen xu zhengyang zhu Dong Fang Zhongdong zhu di college of mechanical and electrical engineering Nanjing University of Aeronautics & Astronautics

Ti60 （Ti-5.6A1-4.8Sn2Zr-1Mo-0.35Si-0.7Nd） is a high-temperature titanium alloy that is now used for important components of aircraft engines. Electrochemical machining （ECM） is a promising technique that has several advantages, such as a high machining rate, and can be used on a wide range of difficult-to-process materials. In this paper, orthogonal experiments are conducted to investigate ECM of Ti60, with the aim of determining the influences of some electrochemical pro- cess parameters on the surface roughness. The most important parameter is found to be the frequency of the pulsed power supply. It is found that using suitably optimized parameters for ECM can greatly decrease the surface roughness ofa workpiece. A surface roughness of approximately 0.912 μm can be obtained with the following optimal parameters： NaC1 electrolyte concentration 13wt%, voltage 20 V, pulse frequency 0.4 kHz, duty cycle 0.3, temperature 23 ℃, and anode feed rate 0.5 mm/min. Furthermore, blisk blades have been successfully processed using these optimized parameters

关键词： Blisk Electrochemical machining(ECM) Surface roughness Titanium alloy Ti60

dissolution Characteristics of New Titanium Alloys in Electrochemical Machining

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Transactions of nanjing university of aeronautics and astronautics 2016年第5期33卷 610-619页

作者： Chen xuezhen zhu Dong xu zhengyang Liu Jia zhu di college of mechanical and electrical engineering Nanjing University of Aeronautics and Astronautics

We focus on the electrochemical dissolution characteristics of new titanium alloys such as near-αtitanium alloy Ti60,α+βtitanium alloy TC4andβtitanium alloy Ti40 which are often used for aerospace *** experiments are carried out by electrochemical machining tool,and the surface morphology of the specimens is observed by the scanning electron microscope(SEM)and three-dimensional video microscope(DVM).The appropriate electrolyte is selected and the relationships between surface roughness and current density are *** results show that the single-phase titanium alloy Ti40 has a better surface roughness after ECM compared with theα+βtitanium alloy TC4 and the near-αtitanium alloy *** best surface roughness is Ra 0.28μm when the current density is 75A/***,the surface roughness of the near-αtitanium alloy Ti60 is the most sensitive with the current density because of the different electrochemical equivalents of substitutional elements and larger grains than ***,the suitable current density for each titanium alloy is achieved.

关键词： electrochemical machining(ECM) titanium alloy substitutional element electrochemical equivalent surface roughness