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Effects of Gap Width and groove on the Mechanical Properties of Butt Joint Between Aluminum Alloy and Stainless Steel

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Acta Metallurgica Sinica(English Letters) 2013年第2期26卷 143-148页

作者： Honggang DONG Chuanqing LIAO School of Materials Science and Engineering Dalian University of Technology Shanghai Aerospace Equipments manufacturer

Butt joining of 5A02 aluminum alloy to 304 stainless steel sheets was conducted using gas tungsten arc welding process with Al-12%Si （wt.%, the same below） and Zn-15%Al flux-cored filler wires. The effects of gap width and groove in steel side on the microstructure and tensile strength of the resultant joints were investigated. For the joint made with 0 mm-wide gap and without groove in steel side, severe incomplete brazing zone occurred along the steel side and bottom surfaces, and consequently seriously deteriorated the joint strength. However, presetting 1.5 mm-wide gap or with groove in steel side could promote the wetting of molten filler metal on the laying surfaces, and then significantly enhance the resultant joint strength. Moreover, post-weld heat treatment could further improve the tensile strength of the joints. During tensile testing, the specimens from the joints made with AI-12%Si flux-cored filler wire fractured through the weld or interracial layer, but those from the heat-treated joints made with Zn-15%AI flux-cored filler wire fractured in the aluminum base metal.

关键词： Aluminum Stainless steel Arc-brazing Gap width groove Mechanical property

Research on the Performance of Supercritical CO_2 Dry Gas Seal with Different Deep Spiral groove

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Journal of Thermal Science 2019年第3期28卷 547-558页

作者： DU Qiuwan ZHANG Di MOE Key Laboratory of Thermo-Fluid Science and Engineering Xi'an Jiaotong University

The performance of supercritical CO_2(SCO_2) dry gas seal(DGS) with different deep spiral groove is investigated with the thermal-fluid-solid coupling method. The performance parameters of DGSs with five different kinds of grooves are obtained. The influence of inlet temperature, inlet pressure, velocity and film thickness on performance is analyzed compared with air DGS. The average film pressure, open force and leakage decrease while the average face temperature and flow velocity increase as the spiral groove number increases. The average film pressure, average face temperature, open force and leakage of DGS with radial different deep groove are higher than those of DGS with circumferential different deep groove respectively under the same spiral groove number while the average flow velocity is the opposite. SCO_2 DGS can generate larger average film pressure, open force and leakage with lower average face temperature than air DGS. SCO_2 DGS could maintain better sealing performance despite larger leakage with the variations of inlet temperature, inlet pressure, velocity and film thickness. The variables hold a more remarkable influence on SCO_2 DGS compared with air DGS.

关键词： supercritical carbon dioxide different deep spiral groove dry gas seal thermal-fluid-solid coupling method

Complete duodenal obstruction induced by groove pancreatitis: A case report

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World Journal of Clinical Cases 2019年第23期7卷 4106-4110页

作者： Ya-Li Wang Chen-Hao Tong Jian-Hua Yu Zhi-Liang Chen Hong Fu Jian-Hui Yang Xin Zhu Bao-Chun Lu Department of Hepatobiliary Surgery Shaoxing People’s Hospital (Shaoxing Hospital Zhejiang University School of Medicine)

BACKGROUND groove pancreatitis(GP)is a type of chronic pancreatitis occurring in an anatomic area between the duodenum,head of the pancreas,and common bile duct.Duodenal obstruction is always caused by malignant pancreatic diseases,such as pancreatic head carcinoma,while is rarely induced by benign pancreatic diseases,such as pancreatitis.CASE SUMMARY A 39-year-old man presented with a 1-mo history of upper abdominal discomfort.His concomitant symptoms were abdominal distension,postprandial nausea,and vomiting.Contrast-enhanced computed tomography of the abdomen showed thickening of the intestinal wall with enhancement of the descending segment of the duodenum,which could not be clearly differentiated from the head of the pancreas.Upper gastrointestinal radiographs and gastrointestinal endoscopy showed a complete obstruction of the descending duodenum.An operation found that a 3-cm mass was located in the“groove part”of the pancreas and oppressing the descending duodenum.Pancreaticoduodenectomy was performed to relieve the obstruction and thoroughly remove the pancreatic lesions.The pathologic diagnosis was pancreatitis.The patient had an uneventful recovery with no complications.CONCLUSION Because of the special location and the contracture induced by long-term chronic inflammation,our case reminds surgeons that some benign pancreatic diseases,such as GP,can also present with symptoms similar to those of pancreatic cancer.This knowledge can help to avoid an unnecessary radical operation.

关键词： groove pancreatitis Duodenal obstruction Pancreatic head carcinoma Case report

Rectangular-to-circular groove waveguide junction

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Science China(Technological Sciences) 2003年第4期46卷 343-348页

作者：崔立成杨鸿生 State Key Laboratory of Millimeter Waves Department of Electronic Engineering Southeast University

Mode matching method is used to analyze the scattering characteristics of the rectangular-to-circular groove waveguide junction. Firstly, the scattering matrix equation is obtained by matching the electromagnetic fields at the boundary of the junction. The scattering coefficients can be obtained from the equation. Secondly the scattering characteristics of the iris with rectangular window positioned in circular groove waveguide are briefly analyzed. Thirdly, the convergent problem is discussed and the numerical results are given. At last experiment is made and good agreement is found between the calculated results and the measured results.

关键词： circular groove waveguide, mode matching method, rectangular-to-circular groove waveguide junction.

Effect of surface topography with different groove angles on tribological behavior of the wheel/rail contact using alternative machine

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Friction 2016年第3期4卷 238-248页

作者： A.KHALLADI K.ELLEUCH Laboratory of Materials Engineering and Environment(LGME) National Engineering School of Sfax(ENIS) University of Sfax Sfax 3038 TunisiaDepartment of Mechanical Higher Institutes of Technological Studies of Sfax(ISET SFAX) University of Sfax Sfax 3099 Tunisia Laboratory of Materials Engineering and Environment(LGME) National Engineering School of Sfax(ENIS) University of Sfax Sfax 3038 Tunisia

The objective of this study was to investigate the influence of the surface topography on the tribological behavior of the wheel/rail contact. Four different groove orientations forming the surface topographies—smooth surface, 0°, 45° and 90°—were manufactured by grinding and compared. All friction tests with different surface topographies were conducted using an alternative tribometer simulating the pure sliding process in the wheel-rail contact. The Hertzian pressure was maintained at 1,000 MPa with two levels of sliding velocity (20 mm/s and 80 mm/s). This study resulted in five main findings. First, the initial surface topographies seemed to have a significant effect on the friction coefficient independently of the speed. Second, the increase of the sliding velocity would decrease the friction coefficient. Third, especially when accompanied with a high sliding velocity, an initial rough surface would have a significant effect on the wear of the wheel. Fourth, the highest wear values were observed at groove orientations of 45° when accompanied with a high sliding velocity. Finally, the break-in duration seemed to depend on the initial surface topographies of the rail and the sliding velocity.

关键词： wheel/rail contact groove friction wear break-in

Tuning the Corrosion Resistance,Antibacterial Activity,and Cytocompatibility by Constructing grooves on the Surface of Ti6Al4V3Cu Alloy

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Acta Metallurgica Sinica(English Letters) 2023年第12期36卷 1979-1998页

作者： Minghui Zhou Hui Sun Yanming Gan Cheng Ji Yan Chen Yanjin Lu Jinxin Lin Qiang Wang Key Laboratory of Optoelectronic Materials Chemistry and Physics Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002China College of Chemistry Fuzhou UniversityFuzhou 350108China Liaoning Provincial Key Laboratory of Oral Diseases School and Hospital of StomatologyChina Medical UniversityShenyang 110002China Fujian College University of Chinese Academy of SciencesFuzhou350002China Fujian Science and Technology Innovation Laboratory for Optoelectronic Information of China Fuzhou 350108China College of Chemistry and Materials Science Fujian Normal UniversityFuzhou 350007China

Ti6Al4V3Cu alloy is a promising biomaterial for combating implant-related infection.However,the antibacterial property of Ti6Al4V3Cu is expected to be enhanced due to the low content of Cu element in titanium.To address this issue,the antibacterial property of Ti6Al4V3Cu was tailored by the grooves with different groove widths(30μm,60μm,and 90μm)that were constructed on the surface of the Ti6Al4V3Cu by selective laser melting.The effect of grooves on corrosion resistance,antibacterial property,and cytocompatibility was investigated.The electrochemical tests showed that the corrosion resistance decreased with increasing groove width.The antibacterial tests indicated that the groove with a width of 30μm and 90μm groups showed better antibacterial activity against S.aureus(>90%)compared with the groove with a width of 60μm.The in vitro study suggested that all samples with different grooves were found to exhibit good cytocompatibility with osteoblast cells.It is considered that creating grooves on Ti6Al4V3Cu by selective laser melting is a promising strategy to enhance the antibacterial activity without sacrificing cytocompatibility.

关键词： Ti6Al4V3Cu groove Corrosion resistance Antibacterial Biocompatibility

Glaciation-induced features or sediment gravity flows——An analytic review

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Journal of Palaeogeography 2023年第4期12卷 487-545页

作者： Mats O.Molen Umea FoU AB Vallmov 61S-90352 Ume aSweden

For more than 150 years, geologic characteristics claimed to be evidence for pre-Pleistocene glaciations have been debated. Advancements in recent decades, in understanding features generated by mainly glacial and mass flow processes, are here reviewed. Detailed studies of data offered in support of prePleistocene glaciations have led to revisions that involve environments of mass movements. Similarities and differences between Quaternary glaciogenic and mass movement features are examined, to provide a more systematic methodology for analysing the origins of more ancient deposits. Analyses and evaluation of data are from a) Quaternary glaciogenic sediments, b) formations which have been assigned to pre-Pleistocene glaciations, and c) formations with comparable features associated with mass movements(and occasionally tectonics). Multiple proxies are assembled to develop correct interpretations of ancient strata. The aim is not per se to reinterpret specific formations and past climate changes, but to enable data to be evaluated using a broader and more inclusive conceptual framework.Regularly occurring pre-Pleistocene features interpreted to be glaciogenic, have often been shown to have few or no Quaternary glaciogenic equivalents. These same features commonly form by sediment gravity flows or other non-glacial processes, which may have led to misinterpretations of ancient deposits. These features include, for example, environmental affinity of fossils, grading, bedding, fabrics, size and appearance of erratics, polished and striated clasts and surfaces(“pavements”), dropstones, and surface microtextures.Recent decades of progress in research relating to glacial and sediment gravity flow processes have resulted in proposals by geologists, based on more detailed field data, more often of an origin by mass movements and tectonism than glaciation.The most coherent data of this review, i.e., appearances of features produced by glaciation, sediment gravity flows and a few other geological processes, are summarized in

关键词： Diamictite Tillite Sediment gravity flow(SGF) Striation groove Dropstone Paleoclimate Fossil vegetation Glaciogenic proxies Surface microtexture Late Paleozoic ice age

groove Design and Microstructure Research of Ultra-Fine Grain Bar Rolling

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Modeling and Numerical Simulation of Material Science 2012年第4期2卷 67-75页

作者： Xuetong Li Lei Cao Minting Wang Fengshan Du College of Mechanical Engineering National Engineering Research Center for Equipment and Technology of Cold Rolling Strip Yanshan University Qinhuangdao China

New flat-oval groove rolling process of multi-direction deformation is proposed to manufacture ultra-fine grain bar. Application of new groove series can introduce uniform large plastic strain into whole cross section of the material, and meanwhile satisfy the requirements of shape and size. Principle of grain refinement, based on experimental research of small specimen, is that grain refinement of ferrite is mainly dynamic recrystallization when low-carbon alloy steel is at low temperature deformation. Relationship of grain size and z-factor is also obtained through experimental research, as well as ultra-fine ferrite grain less than 1 micron. To predict strain, shape, dimensions and grain size of the material in rolling process, numerical simulation model of the warm groove bar rolling process is established via nonlinear finite element method, and distribution of grain size of the final section is obtained via finite element subroutine. The result indicates that ultra-fine grain bar rolling can accomplish at low temperature region.

关键词： Bar FEM Flat-Oval groove Large Plastic Strain Low Temperature Ultra-Fine Grain

SCATTERING OF RAYLEIGH WAVE THROUGH A groove ON SURFACE OF PIEZOELECTRIC CRYSTAL

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中国科学A辑(英文版) 1985年第3期 286-300页

作者：汪承灏陈东培 Institute of Acoustics Academia Sinica Beijing Beijing

A normally incident Rayleigh wave will be scattered on a groove on the surface of a piezoelectric crystal. The investigation of such a scattered field as a fundamental problem on surface wave propagation lays a foundation for analyzing groove grating array devices. In this paper we have taken anisotropy and piezoelectricity of substrate into account and applied the boundary perturbation method to finding a more exact general integral expression of soattored field. Then the integral at a pole of the integrand will contribute to the solution of the reflected surface wave and the reflection coefficient, including its magnitude and phase. As an example, the reflection coefficients of three kinds of crystals, YZ-LiNbO3, ST-quartz and （001）（110）-Bi12GeO20, have been numerically computed and they are in good agreement with the experimental results. Furthermore, with the saddle-point method an asymptotic approach to scattered bulk wave at the far field is deduced and the numerical results of bulk wave r

关键词： SURFACE scattered groove WAVE Rayleigh piezoelectric exact normally grating deduced