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Effects of Surface Roughness on Interface Bonding Performance for 316H Stainless Steel in Hot-Compression Bonding

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Acta Metallurgica Sinica(English Letters) 2023年第5期36卷 771-788页

作者： Yong Zhao Bi-Jun Xie Jin-Long Zhang Qin-Qiang Wang Bin Xu Jiang Guo Zhu-Ji Jin ren-ke kang Dian-Zhong Li key Laboratory for Precision and Non-Traditional Machining Technology of Ministry of Education Dalian University of TechnologyDalian116024China Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang110016China

The metallurgical bonding quality of bonding joints is affected by the substrate surface state in hot-compression bonding(HCB),and the surface roughness is a core indicator of the surface ***,the effects of surface roughness on interface bonding performance(IBP)in the HCB process are unclear for substrates with refractory oxide *** study presents the effects of surface roughness on IBP for 316H stainless steel joints fabricated by HCB.A set of HCB parameters for interface bonding critical state of 316H stainless steel joints was *** HCB experiments were carried out under parameters of interface bonding critical state to amplify the effect of surface *** interface morphologies,element distribution,and tensile properties were used to characterize the *** a result,the formation mechanisms of the interface pits were revealed and the variation trend of pit number with the roughness was ***,the mapping relation between surface roughness and IBP was *** results show that the degree of rotational dynamic recrystallization becomes weaker with the decrease in the surface roughness and the interface bonding mechanism is completely transformed into discontinuous dynamic recrystallization when the roughness is lower than 0.020μm *** number of interfacial pits decreases as the roughness decreases owing to the weakening of oxide scale aggregation and abrasive inclusion *** elongation of the tensile specimen cannot increase significantly while the roughness is lower than 0.698μm Sa.

关键词： Surface roughness Interface bonding performance Hot-compression bonding Mapping relation Critical state

Prescribed time control based on the periodic delayed sliding mode surface without singularities

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Science China(Information Sciences) 2024年第7期67卷 256-270页

作者： Bin ZHOU Yi DING kang-kang ZHANG Guang-ren DUAN Center for Control Theory and Guidance Technology Harbin Institute of Technology

In this paper, nonsingular prescribed-time control is studied based on periodic delayed sliding mode surfaces. Different from the existing sliding mode control, where either singularity problems may appear or the convergence time depends on the initial state, the proposed sliding mode control approaches can achieve prescribed-time convergence without singularity. The proposed nonsingular sliding mode control approaches can be applied to both second-order and high-order nonlinear systems with prescribed-time convergence. As applications of the proposed sliding mode control approaches, the control of hypersonic vehicle systems is revisited. Numerical simulations on the nonlinear model of the hypersonic vehicle system show the effectiveness of the proposed methods.

关键词： prescribed-time control smooth periodic delayed feedback sliding mode control high-order nonlinear systems hypersonic vehicle systems

Study into grinding force in back grinding of wafer with outer rim

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Advances in Manufacturing 2020年第3期8卷 361-368页

作者： Xiang-Long Zhu Yu Li Zhi-Gang Dong ren-ke kang Shang Gao key Laboratory for Precision and Non-traditional Machining Technology of Ministry of Education Dalian University of TechnologyDalian116024People’s Republic of China

Back grinding of wafer with outer rim(BGWOR)is a new method for carrier-less thinning of silicon *** present,the effects of process parameters on the grinding force remain ***,a BGWOR normal grinding force model based on grain depth-of-cut was established,and the relationship between grinding parameters(wheel infeed rate,wheel rotational speed,and chuck rotational speed)and normal grinding force was ***,a series of experiments were performed to verify the BGWOR normal grinding force *** study proves that the BGWOR normal grinding force is related to the rotational direction of the wheel and chuck,and the effect of grinding mark density on the BGWOR normal grinding force cannot be ***,this study provides methods for reducing the grinding force and optimizing the back thinning process of the silicon wafer.

关键词： Silicon wafer Back grinding of wafer with outer rim(BGWOR) Grinding force Grinding mark density

Pylorus-preserving gastrectomy for early gastric cancer

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World Journal of Gastrointestinal Oncology 2024年第3期16卷 653-658页

作者： ke-kang Sun Yong-You Wu Department of Gastrointestinal Surgery The Affiliated Kunshan Hospital to Jiangsu UniversitySuzhou 215300Jiangsu ProvinceChina Department of Gastrointestinal Surgery The Second Affiliated Hospital of Soochow UniversitySuzhou 215008Jiangsu ProvinceChina

Pylorus-preserving gastrectomy(PPG)has been widely accepted as a function-preserving gastrectomy for middle-third early gastric cancer(EGC)with a distal tumor border at least 4 cm proximal to the *** procedure essentially preserves the function of the pyloric sphincter,which requires to preserve the upper third of the stomach and a pyloric cuff at least 2.5 *** suprapyloric and infrapyloric vessels are usually preserved,as are the hepatic and pyloric branches of the vagus *** with distal gastrectomy,PPG has significant advantages in preventing dumping syndrome,body weight loss and bile reflux *** postoperative complications after PPG have reached an acceptable *** can be considered a safe,effective,and superior choice in EGC,and is expected to be extensively performed in the future.

关键词： Gastric cancer Pylorus-preserving gastrectomy Oncological safety Gastric stasis

Sensitivity analysis of the surface integrity of monocrystalline silicon to grinding speed with same grain depth-of-cut

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Advances in Manufacturing 2020年第1期8卷 97-106页

作者： Ping Zhou Zi-Guang Wang Ying Yan Ning Huang ren-ke kang Dong-Ming Guo key Laboratory for Precision and Non-traditional Machining Technology of Ministry of Education.Dalian University of Technology Dalian 116024LiaoningPeople's Republic of China

Mechanisms for removal of materials during the grinding process of monocrystalline silicon have been extensively studied in the past several ***,debates over whether the cutting speed significantly affects the surface integrity are *** address this debate,this study comprehensively investigates the effects of cutting speed on surface roughness,subsurface damage,residual stress,and grinding force for a constant grain *** results illustrate that the changes in the surface roughness and subsurface damage relative to the grinding speed are less obvious when the material is removed in ductile-mode as opposed to in the brittle-ductile mixed mode.A notable finding is that there is no positive correlation between grinding force and surface *** results of this study could be useful for further investigations on fundamental and technical analysis of the precision grinding of brittle materials.

关键词： Rotational grinding Silicon wafer Surface integrity Cutting speed Residual stress

The tangential k-Cauchy-Fueter type operator and Penrose type integral formula on the generalized complex Heisenberg group

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Applied Mathematics(A Journal of Chinese Universities) 2024年第1期39卷 181-190页

作者： ren Guang-zhen SHI Yun kang Qian-qian Department of Mathematics Zhejiang International Studies UniversityHangzhou 310023China Department of Mathematics Zhejiang University of Science and TechnologyHangzhou 310023China

The tangential k-Cauchy-Fueter operator and k-CF functions are counterparts of the tangential Cauchy–Riemann operator and CR functions on the Heisenberg group in the theory of several complex variables,*** this paper,we introduce a Lie group that the Heisenberg group can be imbedded into and call it generalized complex *** investigate quaternionic analysis on the generalized complex *** also give the Penrose integral formula for k-CF functions and construct the tangential k-Cauchy-Fueter complex.

关键词： the generalized complex Heisenberg group the tangential k-Cauchy-Fueter type operator Penrose-type integral formula

Light-triggered fluorochromic cholesteric liquid crystal elastomer with hydrogen-bonded fluorescent switch: dualmodal-switchable circularly polarized luminescence

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Science China Chemistry 2024年第8期67卷 2719-2727页

作者： Siyang Lin Tianqi ren Xianyu Meng Wenxin kang Jinbao Guo key Laboratory of Carbon Fibers and Functional Polymers Ministry of EducationCollege of Materials Science and EngineeringBeijing University of Chemical TechnologyBeijing 100029China

Solid materials with dynamically tunable circularly polarized luminescence(CPL) feature higher security levels and devicefriendly characteristics, showing great superiority in the field of information technology and anti-counterfeiting. To address the limited photoisomerization of fluorescent photoswitch in CPL-active solid materials, here a cholesteric liquid crystal elastomer(CLCE) containing a hydrogen-bonded(H-bonded) polymerizable fluorescent switch AHBA-PSD is prepared. Owing to the good flexibility and low glass-transition temperature of CLCE, AHBA-PSD shows a fast and fully reversible photocyclization/cycloreversion with fluorochromic behavior in CLCE. Further, by controlling the spectral overlapping area between the emission and reflection bands, the CLCE exhibits a strong CPL with a g_(lum) value of up to 0.76 accompanied by a reversible phototunable CPL signal. Meanwhile, the H-bond helps to stabilize the mechanical property, and the force-induced switching-off of CPL signal could be achieved due to the destroyed helical structures by external force. Finally, an automatically-recognized identification card with abundant chiroptical information is demonstrated.

关键词： cholesteric liquid crystal elastomer circularly polarized luminescence fluorescent photoswitch diarylethene photoismerization

A novel method for workpiece deformation prediction by amending initial residual stress based on SVR-GA

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Advances in Manufacturing 2021年第4期9卷 483-495页

作者： Jiang Guo Bin Wang Zeng-Xu He Bo Pan Dong-Xing Du Wen Huang ren-ke kang key Laboratory for Precision and Non-Traditional Machining Technology of Ministry of Education Dalian University of TechnologyDalian 116024LiaoningPeople’s Republic of China Institute of Mechanical Manufacturing Technology China Academy of Engineering PhysicsMianyang 621999SichuanPeople’s Republic of China

High-precision manufactured thin-walled pure copper components are widely adopted in precision physics experiments,which require workpieces with extremely high machining ***-sided lapping is an ultraprecision machining method for obtaining high-precision ***,during double-sided lapping,the residual stress of the components tends to cause deformation,which affects the machining accuracy of the ***,a model to predict workpiece deformation derived from residual stress in actual manufacturing should be *** improve the accuracy of the prediction model,a novel method for predicting workpiece deformation by amending the initial residual stress slightly based on the support vector regression(SVR)and genetic algorithm(GA)is ***,a finite element method model is established for double-sided lapping to understand the deformation ***,the SVR model is utilized to construct the relationship between residual stress and ***,the GA is used to determine the best residual stress adjustment value based on the actual deformation of the ***,the method is validated via double-sided lapping experiments.

关键词： Initial residual stress Double-sided lapping Support vector regression(SVR) Genetic algorithm(GA) Deformation

Smooth particle hydrodynamics modeling of cutting force in milling process of TC4

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Advances in Manufacturing 2019年第4期7卷 364-373页

作者： Xiao-Guang Guo Ming Li Zhi-Gang Dong Rui-Feng Zhai Zhu-Ji Jin ren-ke kang key Laboratory for Precision and Non-traditional Machining Technology of Ministry of Education Dalian University of TechnologyDalian 116024LiaoningPeople's Republic of China

Milling is one of the main methods for processing titanium *** present,the complex process of milling is usually simulated by finite element method,which often has problems in mesh distortion and mesh ***,a meshless three-dimensional milling simulation model was established for TC4 titanium alloy using the smooth particle hydrodynamics(SPH)***,the established SPH model was analyzed by the LS-DYNA software,and the stress distribution,temperature field,and cutting force during milling were studied under specific ***,the cutting force was simulated under different cutting parameters and the effects of these parameters on the cutting force were ***,based on a series of cutting force experiments,the accuracy of the simulation model was *** study proves the feasibility of SPH method in the simulation of titanium alloy milling process and provides novel methods for investigating the processing mechanism and optimizing the processing technology of titanium alloys.

关键词： TC4 titanium Smooth particle hydrodynamics(SPH)-Milling Cutting temperature Cutting force