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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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Oxidation mechanism of high-volume fraction SiCp/Al composite under laser irradiation and subsequent machining

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纳米技术与精密工程(英文) 2023年第3期6卷 34-47页

作者： Hanliang Liu guolong zhao Zhiwen Nian Zhipeng Huang Kai Yang Conghua Liu Peng Wang Zhenkuan Diao Beijing Spacecrafts Beijing 100094People’s Republic of China College of Mechanical and Electrical Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016People’s Republic of China

Conventional mechanical machining of a composite material comprising an aluminum matrix reinforced with a high volume fraction of SiC particles(hereinafter referred to as an SiCp/Al composite)faces problems such as rapid tool wear,high specific cutting force,and poor surface integrity.Instead,a promising method for solving these problems is laser-induced oxidation-assisted milling(LOAM):under laser irradiation,the local workpiece material reacts with oxygen,thus forming loose and porous oxides that are easily removed.In the present work,the oxidation mechanism of SiCp/Al irradiated by a nanosecond pulsed laser is studied to better understand the laser-induced oxidation behavior and control the characteristics of the oxides,with laser irradiation experiments performed on a 65%SiCp/Al composite with various laser parameters and auxiliary gases(oxygen,nitrogen,and argon).With increasing laser pulse energy density,both the ablated groove depth and the width of the heat-affected zone increase.When oxygen is used as the auxiliary gas,an oxide layer composed of SiO_(2)and Al2O3 forms,and CO_(2)is produced and escapes from the material,thereby forming pores in the oxides.However,when nitrogen or argon is used as the auxiliary gas,a recast layer is produced that is relatively difficult to remove.Under laser irradiation,the sputtered material reacts with oxygen to form oxides on both sides of the ablated groove,and as the laser scanning path advances,the produced oxides accumulate to form an oxide layer.LOAM and conventional milling are compared using the same milling parameters,and LOAM is found to be better for reduced milling force and tool wear and improved machined surface quality.

关键词： SiCp/Al composite Oxidation mechanism Nanosecond pulsed laser Laser-induced oxidation Heat-affected zone

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Cutting force model and damage formation mechanism in milling of 70wt%Si/Al composite

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Chinese Journal of Aeronautics 2023年第7期36卷 114-128页

作者： guolong zhao Lianjia XIN Liang LI Yang ZHANG Ning HE Hans Nørgaard HANSEN College of Mechanical and Electrical Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China Department of Civil and Mechanical Engineering Technical University of DenmarkKgs.Lyngby 2800Denmark

High-mass fraction silicon aluminium composite(Si/Al composite) has unique properties of high specific strength, low thermal expansion coefficient, excellent wear resistance and weldability. It has attracted many applications in terms of radar communication, aerospace and automobile industry. However, rapid tool wear resulted from high cutting force and hard abrasion, and damaged machined surfaces are the main problem in machining Si/Al composite. This work aims to reveal the mechanisms of milling-induced damages of 70wt% Si/Al composites. A cutting force analytical model considering the characteristics of both the primary silicon particles and the cutting-edge radius was established. Milling experiments were conducted to verify the validity of the model. The results show that the analytical model exhibits a good consistency with the experimental results, and the error is about 10%. The cutting-edge radius has significant effects on the cutting force, surface roughness and damage formation. With the increase in the cutting-edge radius, both the cutting force and the surface roughness decrease firstly and then increase. When the cutting-edge radius is 27 μm, the surface roughness(Sa) reaches the minimum of 2.3 μm.Milling-induced surface damages mainly contain cracks, pits, scratches, matrix coating and burrs.The damage formation is dominated by the failure mode of primary silicon particles, which includes compressive breakage, intragranular fracture, particle pull-out, and interface debonding. In addition, the high ductility of aluminium matrix leads to matrix coating. This work provides guidance for tool selection and damage inhibition in high-efficiency and high-precision machining of high mass fraction Si/Al composites.

关键词： posite Cutting force analytical model Cutting-edge radius Surface quality Damage formation mechanism

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Laser-induced oxidation assisted micro milling of high aspect ratio microgroove on WC-Co cemented carbide

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Chinese Journal of Aeronautics 2021年第4期34卷 465-475页

作者： guolong zhao Hongjun XIA Yang ZHANG Liang LI Ning HE Hans Nφrgaard HANSEN National Key Laboratory of Science and Technology on Helicopter Transmission Nanjing University of Aeronautics and AstronauticsNanjing 210016China Department of Mechanical Engineering Technical University of DenmarkKgs.Lyngby 2800Denmark

Severe tool wear and poor surface quality are the main problems during micro machining of cemented carbide.In this work,an innovative hybrid process of laser-induced oxidation assisted micro milling(LOMM)was proposed to solve the problems.A nanosecond laser was utilized to induce oxidation of the WC-20%Co material,producing loose oxide which was easy to remove.The micro machinability of the material was improved by laser-induced oxidation.The oxidation mechanisms of cemented carbide were studied.A microgroove with a depth of 2.5 mm and aspect ratio of 5 was fabricated successfully.The milling force,surface quality and tool wear mechanisms were investigated.For comparison,a microgroove was also fabricated with conventional micro milling(COMM)using identical milling parameters.Results revealed that in LOMM the milling force and tool wear rate were extremely low during removing the oxide.The machined surface quality and dimensional accuracy achieved by LOMM were superior to those obtained by COMM.The surface roughness Saof the microgroove bottom reached 88 nm in LOMM,while the cross-sectional geometry of the microgroove was a trapezoid.Perpendicularity of the microgroove sidewall machined by LOMM was better than that by COMM.The tool wear forms in LOMM were coating spalling and slight tool nose breakage.Compared with COMM,the tool life in LOMM was prolonged significantly.It indicates that the proposed hybrid process is an effective and efficient way to fabricate high aspect ratio micro-features with high dimensional accuracy.

关键词： Cemented carbide High aspect ratio Laser-induced oxidation Micro milling Microgroove Tool wear

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Energy principle and material removal sequence optimization method in machining of aircraft monolithic parts

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Chinese Journal of Aeronautics 2020年第10期33卷 2770-2781页

作者： Yinfei YANG Longxin FAN Liang LI guolong zhao Ning HAN Xiaoyue LI Hui TIAN Ning HE College of Mechanical&Electrical Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China AVIC Xi’an Aircraft Industry(Group)Company LTD Xi’an 710089China

In the machining process of aircraft monolithic parts,the initial residual stress redistribution and structural stiffness evolution often lead to unexpected distortions.On the other hand,the stress redistribution and stiffness reduction during the machining process depend on the material removal sequence.The essence of the stress redistribution is releasing the initial elastic strain energy.In the present study,the influence of the material removal sequence on the energy release is studied.Moreover,a novel optimization method is proposed for the material removal sequence.In order to evaluate the performance of the proposed method,the mechanism of the machining distortion is firstly analyzed based on the energy principle.Then a calculative model for the machining distortion of long beam parts is established accordingly.Moreover,an energy parameter related to the bending distortion and the procedure of the material removal sequence optimization is defined.Finally,the bending distortion analysis and material removal sequence optimization are performed on a long beam with a Z-shaped cross-section.Furthermore,simulation and experiments are carried out.The obtained results indicate that the optimized sequence results in a low distortion fluctuation and decreases the bending distortion.

关键词： Aircraft monolithic part Distortion Initial residual stress Material removal sequence Strain energy

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Machining deformation of single-sided component based on finishing allowance optimization

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Chinese Journal of Aeronautics 2020年第9期33卷 2434-2444页

作者： Xiaoyue LI Liang LI Yinfei YANG guolong zhao Ning HE Xiaocen DING Yaowen SHI Longxin FAN Hui LAN Muhammad JAMIL National Key Laboratory of Science and Technology on Helicopter Transmission Nanjing University of Aeronautics and AstronauticsNanjing 210016China AVIC Jiangxi Hongdu A viation Industry Group Company Ltd Nanchang 330000China

Owing to reliability and high strength-to-weight ratio,large thin-walled components are widely used in the aviation and aerospace industry.Due to the complex features and sequence involved in the machining process of large thin-walled components,machining deformation of component is easy to exceed the specification.In order to address the problem,it is important to retain the appropriate finishing allowance.To find the overall machining deformation,finishing allowance-induced deformation(web finishing allowance,sidewall finishing allowance)and initial residual stress-induced deformation were considered as major factors.Meanwhile,machined surface residual stress-induced deformation,clamping stress-induced deformation,thermal deformation,gravity-induced deformation and inertial force-induced deformation were neglected in the optimization model.Six-peak Gaussian function was introduced to fit the initial residual stress.Based upon the obtained function of initial residual stress,a deformation prediction model between initial residual stress and finishing allowance was established to attain the finishing allowanceinduced deformation.In addition,linear programming optimization model based on the simplex algorithm was developed to optimize the overall machining deformation.Results have concluded that the overall machining deformation reached the minimum value when sidewall finishing allowance and web finishing allowance varied between 1 and 2 mm.Additionally,web finishing allowance-induced deformation and sidewall finishing allowance-induced deformation were1.05 mm and 0.7 mm.Furthermore,the machining deformation decreased to 0.3–0.38 mm with the application of optimized finishing allowance allocation strategy,which made 39–56%reduction of the overall machining deformation compared to that in conventional method.

关键词： Finishing allowance Linear programming Machining deformation Residual stresses Simplex algorithm

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不道德亲组织行为的解释机制与权变理论模型

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大连民族大学学报 2024年第4期26卷 320-324页

作者：栾宇翔赵国龙中国人民大学劳动人事学院北京100872 商务部国际贸易经济合作研究院北京100710

不道德亲组织行为(Unethical Pro-organizational Behavior)是指员工为维护组织利益而采取的不道德行为。在数字化环境下,员工的不道德亲组织行为可能会带来更严重的负面影响,但现有研究对此尚未给予足够的重视。因此有必要梳理不道德... 详细信息

不道德亲组织行为(Unethical Pro-organizational Behavior)是指员工为维护组织利益而采取的不道德行为。在数字化环境下,员工的不道德亲组织行为可能会带来更严重的负面影响,但现有研究对此尚未给予足够的重视。因此有必要梳理不道德亲组织行为的概念内涵,并从社会交换、社会认同、社会认知及社会学习等四个理论机制出发,探讨该行为的前因。在此基础上,提出了一个基于权变理论的研究模型,旨在揭示不道德亲组织行为对个体和组织层面的影响结果。结论丰富了对不道德亲组织行为的理论研究,并为管理实践提供了有价值的参考。

关键词：不道德亲组织行为社会交换社会认同社会认知社会学习权变理论

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河北省数字治理变革和政务服务效能提升路径研究

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广西科技师范学院学报 2024年第1期39卷 67-76页

作者：刘雪丽赵国龙史亚杰北华航天工业学院马克思主义学院河北廊坊065000 中国石油管道局工程有限公司河北廊坊065000

构建高效能政府,是提升政府政务服务质量和实现政府治理能力现代化的必然要求。随着数字技术和数字经济的快速发展,河北省开始大力推行数字治理变革,创新政务服务模式,极大提升了河北省政务服务效能,优化了河北省数字经济快速发展的营... 详细信息

构建高效能政府,是提升政府政务服务质量和实现政府治理能力现代化的必然要求。随着数字技术和数字经济的快速发展,河北省开始大力推行数字治理变革,创新政务服务模式,极大提升了河北省政务服务效能,优化了河北省数字经济快速发展的营商环境。但是,河北省仍存在一些制约政务服务效能提升的因素,如各地线上政务服务供给能力存在一定差异、线上数据资源共享与业务协同有待深化、政务服务相关配套制度有待进一步完善等,这需要从加强顶层设计、优化政务服务、加强数据应用以及健全制度体系等方面入手,进一步促进河北省数字治理变革和政务服务效能提升。

关键词：数字治理政务服务效能数字政府互联网+ 流程再造

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Two intestinal microbiota-derived metabolites, deoxycholic acid and butyrate, synergize to enhance host defense peptide synthesis and alleviate necrotic enteritis

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Journal of Animal Science and Biotechnology 2024年第3期15卷 1158-1172页

作者： Dohyung M.Kim Jing Liu Melanie A.Whitmore Isabel Tobin Zijun zhao guolong Zhang Department of Animal and Food Sciences Oklahoma State UniversityStillwaterOKUSA

Background Necrotic enteritis(NE)is a major enteric disease in poultry,yet effective mitigation strategies remain elusive.Deoxycholic acid(DCA)and butyrate,two major metabolites derived from the intestinal microbiota,have independently been shown to induce host defense peptide(HDP)synthesis.However,the potential synergy between these two compounds remains unexplored.Methods To investigate the possible synergistic effect between DCA and butyrate in regulating HDP synthesis and barrier function,we treated chicken HD11 macrophage cells and jejunal explants with DCA and sodium butyrate(NaB),either individually or in combination,for 24 h.Subsequently,we performed RNA isolation and reverse transcrip-tion-quantitative PCR to analyze HDP genes as well as the major genes associated with barrier function.To further determine the synergy between DCA and NaB in enhancing NE resistance,we conducted two independent trials with Cobb broiler chicks.In each trial,the diet was supplemented with DCA or NaB on the day-of-hatch,followed by NE induction through sequential challenges with Eimeria maxima and Clostridium perfringens on d 10 and 14,respectively.We recorded animal mortality after infection and assessed intestinal lesions on d 17.The impact of DCA and NaB on the microbiota in the ileum and cecum was evaluated through bacterial 16S rRNA gene sequencing.Results We found that the combination of DCA and NaB synergistically induced multiple HDP genes in both chicken HD11 cells and jejunal explants.Additionally,the gene for claudin-1,a major tight junction protein,also exhibited synergistic induction in response to DCA and NaB.Furthermore,dietary supplementation with a combination of 0.75 g/kg DCA and 1 g/kg NaB led to a significant improvement in animal survival and a reduction in intestinal lesions compared to either compound alone in a chicken model of NE.Notably,the cecal microbiota of NE-infected chickens showed a marked decrease in SCFA-producing bacteria such as Bacteroides,Faecalibacterium,and Cuneatibacter,with lactobaci

关键词： Bile acids Host defense peptides Metabolites Microbiome Necrotic enteritis Short-chain fatty acids

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复合材料的高效高质量铣磨复合加工技术研究

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当代化工研究 2024年第10期 153-157页

作者：郭鑫王珉年智文赵国龙杨吟飞唐小聪南京市计量监督检测院江苏210049 南京航空航天大学江苏210016

连续碳纤维增强碳化硅基(Cf/SiC)复合材料具有耐高温、高比强度、高比模量等优良性能,被广泛应用于航空航天、轨道交通、国防等各大尖端领域。然而其作为典型难加工材料的代表,加工过程存在加工效率低、加工表面质量差等加工难点。本文... 详细信息

连续碳纤维增强碳化硅基(Cf/SiC)复合材料具有耐高温、高比强度、高比模量等优良性能,被广泛应用于航空航天、轨道交通、国防等各大尖端领域。然而其作为典型难加工材料的代表,加工过程存在加工效率低、加工表面质量差等加工难点。本文以Cf/SiC复合材料为研究对象,基于铣削和磨削的正交试验优选工艺参数,并基于优选后的铣削加工和磨削加工参数提出高效高质量加工方案,通过开展对比试验来验证高效高质量加工方案的优越性,最终加工效率提高超100%,表面粗糙度降低超30%。

关键词： Cf/SiC复合材料铣削磨削加工效率

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