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Science China(Technological Sciences) 2015年第11期58卷 1877-1883页

作者： GAO Hang WANG Xu TENG XiaoJi GUO DongMing key laboratory for precision and non-traditional machining technology of ministry of education Dalian University of Technology

In this paper, a micro water dissolution machining(MWDM) principle is proposed for machining potassium dihydrogen phosphate(KDP) crystal using water-in-oil micro-emulsion as an abrasive-free polishing fluid. In addition, two instances of the application of this principle to ultra-precision machining of KDP crystals are presented. Computer-controlled optical surfacing(CCOS) and diamond wire cutting(DWC) process were carried out according to the MWDM principle. In the case of the CCOS technology, it is found that the micro-waviness was removed completely by following the MWDM principle. The surface undulation decreased from 40 nm to less than 10 nm, and the surface root-mean-square(rms) roughness obviously reduced from 8.147 to 2.660 nm. In the case of the DWC process, the surface rms roughness reduced from 8.012 to 2.391 μm, and the cutting efficiency was improved. These results indicate that the MWDM principle can efficiently improve the machining quality of KDP optical crystal and has a great potential to machine water-soluble materials.

关键词：超精密加工 KDP晶体加工原理水溶解应用表面粗糙度测量原理光学表面

Effect of substrate curvature on thickness distribution of polydimethylsiloxane thin film in spin coating process

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Chinese Physics B 2018年第6期27卷 479-487页

作者：闫英周平张尚雄郭晓光郭东明 key laboratory for precision and non-traditional machining technology of ministry of education Dalian University of Technology

The polymer spin coating is critical in flexible electronic manufaction and micro-electro-mechanical system（MEMS）devices due to its simple operation, and uniformly coated layers. Some researchers focus on the effects of spin coating parameters such as wafer rotating speed, the viscosity of the coating liquid and solvent evaporation on final film thickness.In this work, the influence of substrate curvature on film thickness distribution is considered. A new parameter which represents the edge bead effect ratio（re） is proposed to investigate the influence factor of edge bead effect. Several operation parameters including the curvature of the substrate and the wafer-spin speed are taken into account to study the effects on the film thickness uniformity and edge-bead ratio. The morphologies and film thickness values of the spin-coated PDMS films under various substrate curvatures and coating speeds are measured with laser confocal microscopy. According to the results, both the convex and concave substrate will help to reduce the edge-bead effect significantly and thin film with better surface morphology can be obtained at high spin speed. Additionally, the relationship between the edge-bead ratio and the thin film thickness is like parabolic curve instead of linear dependence. This work may contribute to the mass production of flexible electronic devices.

关键词： spin coating non-planar substrate film thickness distribution edge-bead effect

A multi-order method for predicting stability of a multi-delay milling system considering helix angle and run-out effects

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Chinese Journal of Aeronautics 2018年第6期31卷 1375-1387页

作者： Shanglei JIANG Yuwen SUN key laboratory for precision and non-traditional machining technology of the ministry of education Dalian University of Technology

In this paper, a multi-delay milling system considering helix angle and run-out effects is firstly established. An exponential cutting force model is used to model the interaction between a work-piece and a cutting tool, and a new approach is presented for accurately calibrating exponential cutting force coefficients and cutter run-out parameters. Furthermore, based on an implicit multi-step Adams formula and an improved precise time-integration algorithm, a novel stability prediction method is proposed to predict the stability of the system. The involved time delay term and periodic coefficient term are integrated as a comprehensive state term in the integral response which is approximated by the Adams formula. Then, a Floquet transition matrix with an arbitraryorder form is constructed by using a series of matrix multiplication, and the stability of the system is determined by the Floquet theory. Compared to classical semi-discretization methods and fulldiscretization methods, the developed method shows a good performance in convergence, efficiency,accuracy, and multi-order complexity. A series of cutting tests is further carried out to validate the practicability and effectiveness of the proposed method. The results show that the calibration process needs a time of less than 5 min, and the stability prediction method is effective.

关键词： Cutting force Floquet theory Milling stability Multi-delay milling system Run-out

Explicit Correlation Model of Multi-source Constraints for Re-design Parts with Complex Curved Surface

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Chinese Journal of Mechanical Engineering 2014年第2期27卷 385-391页

作者： JIA Zhenyuan WANG Fuji WANG Yongqing GUO Dongming key laboratory for precision and non-traditional machining technology of ministry of education Dalian University of Technology

In precision machining of complex curved surface parts with high performance, geometry accuracy is not the only constraint, but the performance should also be met. Performance of this kind of parts is closely related to the geometrical and physical parameters, so the final actual size and shape are affected by multiple source constraints, such as geometry, physics, and performance. These parts are rather difficult to be manufactured and new manufacturing method according to performance requirement is urgently needed. Based on performance and manufacturing requirements for complex curved surface parts, a new classification method is proposed, which divided the complex curved surface parts into two categories： surface re-design complex curved surface parts with multi-source constraints（PRCS） and surface unique complex curved surface parts with pure geometric constraints（PUCS）. A correlation model is constructed between the performance and multi-source constraints for PRCS, which reveals the correlation between the performance and multi-source constraints. A re-design method is also developed. Through solving the correlation model of the typical paws performance-associated surface, the mapping relation between the performance-associated surface and the related removal amount is obtained. The explicit correlation model and the method for the corresponding related removal amount of the performance-associated surface are built based on the classification of surface re-design complex curved surface parts with multi-source constraints. Research results have been used in the actual processing of the typical parts such as radome, common bottom components, nozzle, et al., which shows improved efficiency and accuracy of the precision machining for the surface re-design parts with complex curved surface.

关键词： multi-source constraints surface re-design performance associated surface explicit correlation model

VARIABLE FEEDRATE INTERPOLATION OF NURBS TOOLPATH WITH GEOMETRIC AND KINEMATICAL CONSTRAINTS FOR FIVE-AXIS CNC machining

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Journal of Systems Science & Complexity 2013年第5期26卷 757-776页

作者： SUN Yuwen ZHOU Jianfeng GUO Dongming key laboratory for precision and non- traditional machining technology of the ministry of education Dalian University of Technology

Variable feedrate interpolation algorithms for five-axis parametric toolpath are very promising but still rather limited currently.In this paper,an off-line feedrate scheduling method of dual NURBS curve is presented with geometric and kinematical constraints.For a given dual parametric curve,the feedrates of sampling points are first scheduled sequent with confined feedrate of cutter tip and machine pivot,chord error,normal acceleration and angular feedrate.Then,the feedrate profiles of angular feed acceleration sensitive regions of the path are adjusted using a bi-directional scanning algorithm.After that,a linear programming method is used to adjust the feedrate profiles of linear feed acceleration sensitive regions and control the linear feed acceleration of both cutter tip and machine pivot within preset values.Further,a NURBS curve is used to fit the feedrates of sampling points.Finally,illustrative examples are carried out to validate the feasibility of the proposed feedrate scheduling method.The results show that the proposed method has the ability of effectively controlling the angular feed characters of cutter axis as well as the chord error and linear feed characters of cutter tip and machine pivot,and it has potential to be used in high accuracy and high quality five-axis machining.

关键词： NURBS曲线五轴数控加工进给速度刀具路径插补算法运动学几何学调度方法

Material removal rate in chemical-mechanical polishing of wafers based on particle trajectories

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Journal of Semiconductors 2010年第5期31卷 145-150页

作者：苏建修陈锡渠杜家熙康仁科 Henan Institute of Science and technology key laboratory for precision and non-traditional machining of ministry of education Dalian University of Technology

Distribution forms of abrasives in the chemical mechanical polishing（CMP） process are analyzed based on experimental results.Then the relationships between the wafer,the abrasive and the polishing pad are analyzed based on kinematics and contact mechanics.According to the track length of abrasives on the wafer surface,the relationships between the material removal rate and the polishing velocity are obtained.The analysis results are in accord with the experimental results.The conclusion provides a theoretical guide for further understanding the material removal mechanism of wafers in CMP.

关键词： chemical mechanical polishing material removal mechanism abrasive material removal rate

Nanoindentation on the doubler plane of KDP single crystal

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Journal of Semiconductors 2013年第3期34卷 21-25页

作者：郭晓光张小冀唐宪钊郭东明高航滕晓辑 key laboratory for precision and non-traditional machining technology of ministry of education Dalian University of Technology

The nanohardness is from 1.44 to 2.61 GPa,the Vickers hardness is from 127 to 252 Vickers,and elastic modulus is from 52 to 123 GPa by the nanoindentation experiments on the doubler plane of KDP crystal. An indentation size effect is observed on the doubler plane in the test as the nanohardness and elastic modulus decreases with the increase of the maximum load.Slippage is identified as the major mode of plastic deformation, and pop-in events are attributed to the initiation of slippage.And the variation of unloading curve end is the result of stick effects between the indenter and the contact surface.The depth of the elastic deformation,which is between 40 and 75 nm,is responsible for the elastic deformation.The doubler plane of KDP crystal has anisotropy,and the relative anisotropy of nanohardness is 8.2%and the relative anisotropy of elastic modulus is 8.0%.

关键词： KDP crystal the doubler plane nanoindentation size effect anisotropy

High-temperature wear mechanisms of TiNbWN films:Role of nanocrystalline oxides formation

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Friction 2023年第3期11卷 460-472页

作者： Leilei CHEN Zhenyu ZHANG Ming LOU Kai XU Lu WANG Fanning MENG Denis MUSIC Keke CHANG key laboratory for precision and non-traditional machining technology of ministry of education Dalian University of TechnologyDalian 116024China key laboratory of Marine Materials and Related Technologies Zhejiang Key Laboratory of Marine Materials and Protective TechnologiesNingbo Institute of Materials Technology and EngineeringChinese Academy of SciencesNingbo 315201China Department of Materials Science and Applied Mathematics Malmo UniversityMalmö20506Sweden

Réfractory high/medium entropy nitrides(HENs/MENs)exhibit comprehensive application prospects as protective films on mechanical parts,particularly those subjected to sliding contacts at elevated temperatures.In this study,a new MEN system TiNbWN,forming a single fc solution,is designed and its wear performance at temperatures ranging from 25 to 750℃is explored.The wear mechanisms can be rationalized by examining the subsurface microstructural evolutions using the transmission electron microscopy as well as calculating the phase diagrams and interfacial adhesion behavior employing calculation of phase diagram(CALPHAD)and density functional theory(DFT).To be specific,increased wear losses occur in a temperature range of 25-600℃,being predominantly caused by the thermally-induced hardness degradation;whereas at the ultimate temperature(750℃),the wear loss is refrained due to the formation of nanocrystalline oxides(WnO_(3n-2r)TiO_(2),and TiOx),as synergistically revealed by microscopy and CALPHAD,which not only enhance the mechanical properties of the pristine nitride film,but also act as solid lubricants,reducing the interfacial adhesion.Thus,our work delineates the role of the in situ formed nanocrystalline oxides in the wear mechanism transition of TiNbWN thin films,which could shed light on the high-temperature wear behavior of refractory HEN/MENfilms.

关键词： high/medium entropy nitrides(HENs/MENs) TiNbWN thin films wear mechanisms nanocrystalline oxides

Relationship between coupler curve properties of a 4-bar linkage and its dimensional types

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Science China(Technological Sciences) 2004年第4期47卷 479-487页

作者： CHU Jinkui WANG Liding WU Chen key laboratory for Dalian University of technology precision & non-traditional machining of ministry of education Dalian 116023 China Key Laboratory for Dalian University of Technology Precision & Non-traditional Machining of Ministry of Education Dalian 116023 China Key Laboratory for Dalian University of Technology Precision & Non-traditional Machining of Ministry of Education Dalian 116023 China

Three types of 4-bar linkages can trace the same coupler curve according to the cognate mechanism law. Based on the investigation of the relationship between dimensions of a linkage and the harmonic component characteristic parameters of the coupler curve of the linkage, it was found that six types of linkages are related to the same coupler curve, and they belong to two groups of cognate mechanisms, in which the coupler curves have the same shape and are symmetric. The relationships among the dimensional types of these six mechanisms are presented. The corresponding examples have also proved these conclusions. This work enriches the cognate mechanism law, and can result in more candidate mechanisms for mechanism dimensional synthesis.

关键词： 4-bar linkages, cognate mechanisms, dimensional type.

Implementation strategies for high accuracy grinding of hydrodynamic seal ring with wavy face for reactor coolant pumps

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Science China(Technological Sciences) 2013年第10期56卷 2403-2412页

作者： FENG Guang GUO DongMing HUO FengWei JIN ZhuJi KANG RenKe key laboratory for precision and non-traditional machining technology of ministry of education Dalian University of Technology

Large size mechanical seals are one of the most important components used in reactor coolant pumps.However,the hydrodynamic seal rings with wavy face are difficult to machine due to their high hardness and high form accuracy demand.In order to solve this difficult problem,a novel four-axis linkage grinding method using a cup wheel to process the hydrodynamic seal rings by line contact was proposed.A preliminary study indicates that the form error of the ground seal ring surface is extremely sensitive to different linkage relations of the four axes.By taking the center height of the cup wheel and the laws of motion along the X-axis,Z-axis,B-axis and C-axis as control variables,their effects on the principle form error of the ground surface are evaluated.Six implementation strategies are proposed to reach lower principle form errors.It is found that the minimal principle form error is only 9.64 nm and hence its influence on the ground seal ring shape can be neglected in designing an ultra-precision grinding machine.In addition,the results indicate that the position accuracy of the X-axis at the microscale is acceptable no matter which implementation strategy is selected.This study is expected to serve as a theoretical basis for design and development of the four-axis ultra-precision grinding machine.

关键词：流体动压冷却剂泵密封环研磨机反应堆波浪形高精度形状误差