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Multiple Response Optimization of Three-Body Abrasive Wear Behaviour of Graphite Filled Carbon-Epoxy ComPosites Using Grey-Based Taguchi Approach
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作者 K.M. Subbaya N. Rajendra +1 位作者 Y.S. Varadarajan B. Suresha 《Journal of Minerals and Materials Characterization and Engineering》 2012年第9期876-884,共9页
The three-body abrasive wear behaviour of carbon fabric reinforced epoxy (C-E) composites has been evaluated by the addition of graphite (G) particles as a secondary reinforcement. Three-body abrasive wear test were c... The three-body abrasive wear behaviour of carbon fabric reinforced epoxy (C-E) composites has been evaluated by the addition of graphite (G) particles as a secondary reinforcement. Three-body abrasive wear test were conducted using dry sand rubber wheel abrasion tester as per ASTM G-65 with three process parameters load, abrading distance and filler content. To assess the abrasive wear behaviour of particulate filled C-E composites satisfying multiple performance measure, grey-based Taguchi approach has been adopted. The experiments were designed according to Taguchi’s orthogonal array (L?27). The grey relational analysis was applied to convert a multi response process optimization to a single response. Using analysis of variance, significant contributions of process parameters have been determined. The results indicate that the addition of graphite particles into C-E composite increased the wear resistance considerably. It was observed that highest wear resistance of C-E composite was achieved with incorporation of 10 wt. % of graphite filler. Results indicate that the filler content and grit size of abrasive paper were found to be the most significant factor which has influence on the abrasive wear of C-E composite. The worn surface features were examined through scanning electron microscope to probe the wear mechanism. 展开更多
关键词 Composites three-body abrasION GREY RELATIONAL Analysis Scanning Electron MICROSCOPE
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Contact Mechanism of Rail Grinding with Open-Structured Abrasive Belt Based on Pressure Grinding Plate 被引量:4
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作者 Zhiwei Wu Wengang Fan +1 位作者 Chang Qian Guangyou Hou 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2023年第2期341-351,共11页
The current research of abrasive belt grinding rail mainly focuses on the contact mechanism and structural design.Compared with the closed structure abrasive belt grinding,open-structured abrasive belt grinding has ex... The current research of abrasive belt grinding rail mainly focuses on the contact mechanism and structural design.Compared with the closed structure abrasive belt grinding,open-structured abrasive belt grinding has excellent performance in dynamic stability,consistency of grinding quality,extension of grinding mileage and improvement of working efficiency.However,in the contact structure design,the open-structured abrasive belt grinding rail using a profiling pressure grinding plate and the closed structure abrasive belt using the contact wheel are different,and the contact mechanisms of the two are different.In this paper,based on the conformal contact and Hertz theory,the contact mechanism of the pressure grinding plate,abrasive belt and rail is analyzed.Through finite element simulation and static pressure experiment,the contact behavior of pressure grinding plate,abrasive belt and rail under single concentrated force,uniform force and multiple concentrated force was studied,and the distribution characteristics of contact stress on rail surface were observed.The results show that under the same external load,there are three contact areas under the three loading modes.The outer contour of the middle contact area is rectangular,and the inner contour is elliptical.In the contact area at both ends,the stress is extremely small under a single concentrated force,the internal stress is drop-shaped under a uniform force,and the internal stress under multiple concentration forces is elliptical.Compared with the three,the maximum stress is the smallest and the stress distribution is more uniform under multiple concentrated forces.Therefore,the multiple concentrated forces is the best grinding pressure loading mode.The research provides support for the application of rail grinding with open-structured abrasive belt based on pressure grinding plate,such as contact mechanism and grinding pressure mode selection. 展开更多
关键词 Rail grinding abrasive belt Pressure grinding plate Contact stress
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Rock breaking performance of the newly proposed unsubmerged cavitating abrasive waterjet
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作者 Chenxing Fan Haitao Zhang +2 位作者 Yong Kang Hanqing Shi Deng Li 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2023年第7期843-853,共11页
To improve the rock breaking ability, cavitating waterjet and abrasive waterjet are combined by using a coaxial low-speed waterjet generated around the periphery of a high-speed abrasive waterjet, and a new type of wa... To improve the rock breaking ability, cavitating waterjet and abrasive waterjet are combined by using a coaxial low-speed waterjet generated around the periphery of a high-speed abrasive waterjet, and a new type of waterjet called unsubmerged cavitating abrasive waterjet(UCAWJ) is thus produced. The rock breaking performance of UCAWJ was compared with submerged cavitating abrasive waterjet(SCAWJ)and unsubmerged abrasive waterjet(UAWJ) by impinging sandstone specimens. Moreover, the effects of jet pressure, standoff distance, abrasive flow rate and concentration were studied by evaluating the specific energy consumption, and the area, depth, and mass loss of the eroded specimen. The results show that the artificially generated submerged environment in UCAWJ is able to enhance the rock breaking performance under the same operating parameters. Furthermore, the rock breaking performance of UCAWJ is much better at higher jet pressures and smaller standoff distances when compared with UAWJ. The greatest rock breaking ability of UCAWJ appears at jet pressure of 50 MPa and standoff distance of 32 mm, with the mass loss of sandstone increased by 370.6% and the energy dissipation decreased by 75.8%. In addition, under the experimental conditions the optimal abrasive flow rate and concentration are 76.5 m L/min and 3%, respectively. 展开更多
关键词 Rock breaking abrasive waterjet Unsubmerged cavitation EROSION Specific energy consumption
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Multi-physical Modeling and Adjusting for Ultrasonic Assisted Soft Abrasive Flow Processing
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作者 Yesha Ni Yunfeng Tan Dapeng Tan 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2023年第4期111-124,共14页
The polishing efficiency of the soft abrasive flow(SAF)method is low,which is not in line with the concept of carbon emission reduction in industrial production.To address the above issue,a two-phase fluid multi-physi... The polishing efficiency of the soft abrasive flow(SAF)method is low,which is not in line with the concept of carbon emission reduction in industrial production.To address the above issue,a two-phase fluid multi-physics modeling method for ultrasonic-assisted SAF processing is proposed.The acoustics-fluid coupling mechanic model based on the realizable k-ε model and Helmholtz equation is built to analyze the cavitation effect.The results show that the pro-posed modeling and solution method oriented to ultrasonic-assisted SAF processing have better revealed the flow field evolution mechanism.The turbulence kinetic energy at different ultrasonic frequencies and amplitudes is stud-ied.Simulation results show that the ultrasonic vibration can induce a cavitation effect in the constrained flow chan-nel and promote the turbulence intensity and uniformity of the abrasive flow.A set of comparative polishing experiments with or without ultrasonic vibration are conducted to explore the performance of the proposed method.It can be found that the ultrasonic-assisted SAF method can improve the machining efficiency and uniformity,to achieve the purpose of carbon emission reduction.The relevant result can offer a helpful reference for the SAF method. 展开更多
关键词 Soft abrasive flow Ultrasonic vibration Cavitation effect Polishing efficiency Turbulent kinetic energy
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Efect of Micro Abrasive Slurry Jet Polishing on Properties of Coated Cemented Carbide Tools
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作者 Rongjuan Wang Chengyong Wang 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2023年第5期109-119,共11页
Owing to the popularization of coating technology, physical Vapor Deposition (PVD) coated tools have become indispensable in the cutting process. Additionally, the post-treatment of coated tools applied to industrial ... Owing to the popularization of coating technology, physical Vapor Deposition (PVD) coated tools have become indispensable in the cutting process. Additionally, the post-treatment of coated tools applied to industrial production can efectively enhance the surface quality of coating. To improve the processing performance of coated tools, micro abrasive slurry jet (MASJ) polishing technology is frst applied to the post-treatment of coated tools. Subsequently, the efects of process parameters on the surface quality and cutting thickness of coating are investigated via single-factor experiments. In the experiment, the best surface roughness is obtained by setting the working pressure to 0.4 MPa, particle size to 3 μm, incidence angle to 30°, and abrasive mass concentration to 100 g/L. Based on the results of the single-factor experiments, combination experiments are designed, and three types of coated tools with diferent surface qualities and coating thicknesses are obtained. The MASJ process for the post-treatment of coated tools is investigated based on a tool wear experiment and the efects of cutting parameters on the cutting force and workpiece surface quality of three types of cutting tools. The result indicates that MASJ machining can efectively improve the machining performance of coated tools. 展开更多
关键词 Micro abrasive slurry jet POST-TREATMENT Coated tools Turning Surface roughness
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Experimental Abrasion Study of the Evolution of Gold Morphological Criteria in Different Sediments as a Function of Time
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作者 Fary Diome 《Open Journal of Soil Science》 2024年第1期13-27,共15页
The use of gold as a tracer element for understanding the mode of emplacement of these formations requires a good knowledge of its dynamics. To this end, we have carried out experimental studies to investigate the evo... The use of gold as a tracer element for understanding the mode of emplacement of these formations requires a good knowledge of its dynamics. To this end, we have carried out experimental studies to investigate the evolution of contour states (regular, irregular), surface states (blunt, rough), shape (elongation) and dimension (size). The study of these criteria is carried out on SEM photos of particles, taken before and after the experiment, using Aphelion image processing software. Five experiments were carried out to study the influence of sediment granulometry and water dilution on particle morphological changes. The results of these experiments show that coarse sediments (>1 mm) are largely responsible for morphological changes in gold. They cause fragmentation and/or folding of the particle edges, depending on the magnitude of the impact forces. Strong impacts due to high water dilution cause staking on the particle surface. Fine sediments (<1 mm) slow down particle evolution as they cushion impacts and particles tend to flatten rather than fragment. 展开更多
关键词 Weathering Mantles Experimental abrasion GOLD
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STUDIES ON MAGNETIC ABRASIVE MACHINING
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作者 吴健 王珉 +1 位作者 左敦稳 李亮 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 1997年第1期47-52,共6页
This paper deals with the machining process using magnetic abrasives. Using an apparatus designed and made, a series of experiments are carried out, where the workpiece is cylindrical and the magnetic abrasives used ... This paper deals with the machining process using magnetic abrasives. Using an apparatus designed and made, a series of experiments are carried out, where the workpiece is cylindrical and the magnetic abrasives used are mainly Fe and Al 2O 3, for investigating the effects of machining time, working gap, rotating speed of workpieces, magnetic flux density on machining efficiency and surface roughness. At the end of this paper, the machining mechanism is also discussed. 展开更多
关键词 GRINDING surface roughness magnetic abrasive magnetic field density
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Abrasive Waterjet Machining Simulation by Coupling Smoothed Particle Hydrodynamics /Finite Element Method 被引量:10
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作者 WANG Jianming GAO Na GONG Wenjun 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2010年第5期568-573,共6页
In dealing with abrasive waterjet machining(AWJM) simulation,most literatures apply finite element method(FEM) to build pure waterjet models or single abrasive particle erosion models.To overcome the mesh distorti... In dealing with abrasive waterjet machining(AWJM) simulation,most literatures apply finite element method(FEM) to build pure waterjet models or single abrasive particle erosion models.To overcome the mesh distortion caused by large deformation using FEM and to consider the effects of both water and abrasive,the smoothed particle hydrodynamics(SPH) coupled FEM modeling for AWJM simulation is presented,in which the abrasive waterjet is modeled by SPH particles and the target material is modeled by FEM.The two parts interact through contact algorithm.Utilizing this model,abrasive waterjet with high velocity penetrating the target materials is simulated and the mechanism of erosion is depicted.The relationships between the depth of penetration and jet parameters,including water pressure and traverse speed,etc,are analyzed based on the simulation.The simulation results agree well with the existed experimental data.The mixing multi-materials SPH particles,which contain abrasive and water,are adopted by means of the randomized algorithm and material model for the abrasive is presented.The study will not only provide a new powerful tool for the simulation of abrasive waterjet machining,but also be beneficial to understand its cutting mechanism and optimize the operating parameters. 展开更多
关键词 abrasive waterjet machining randomized algorithm coupling SPH/FEM abrasive material models
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New Iron-based SiC Spherical Composite Magnetic Abrasive for Magnetic Abrasive Finishing 被引量:12
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作者 ZHANG Guixiang ZHAO Yugang +2 位作者 ZHAO Dongbiao ZUO Dunwen YIN Fengshi 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2013年第2期377-383,共7页
SiC magnetic abrasive is used to polish surfaces of precise, complex parts which are hard, brittle and highly corrosion-resistant in magnetic abrasive finishing(MAF). Various techniques are employed to produce this ... SiC magnetic abrasive is used to polish surfaces of precise, complex parts which are hard, brittle and highly corrosion-resistant in magnetic abrasive finishing(MAF). Various techniques are employed to produce this magnetic abrasive, but few can meet production demands because they are usually time-consuming, complex with high cost, and the magnetic abrasives made by these techniques have irregular shape and low bonding strength that result in low processing efficiency and shorter service life. Therefore, an attempt is made by combining gas atomization and rapid solidification to fabricate a new iron-based SiC spherical composite magnetic abrasive. The experimental system to prepare this new magnetic abrasive is constructed according to the characteristics of gas atomization and rapid solidification process and the performance requirements of magnetic abrasive. The new iron-based SiC spherical composite magnetic abrasive is prepared successfully when the machining parameters and the composition proportion of the raw materials are controlled properly. Its morphology, microstructure, phase composition are characterized by scanning electron microscope(SEM) and X-ray diffraction(XRD) analysis. The MAF tests on plate of mold steel S136 are carried out without grinding lubricant to assess the finishing performance and service life of this new SiC magnetic abrasive. The surface roughness(Ra) of the plate worked is rapidly reduced to 0.051 μm from an initial value of 0.372 μm within 5 min. The MAF test is carried on to find that the service life of this new SiC magnetic abrasive reaches to 155 min. The results indicate that this process presented is feasible to prepare the new SiC magnetic abrasive; and compared with previous magnetic abrasives, the new SiC spherical composite magnetic abrasive has excellent finishing performance, high processing efficiency and longer service life. The presented method to fabricate magnetic abrasive through gas atomization and rapid solidification presented can significantly improve the finishing performance and service life of magnetic abrasive, and provide a more practical approach for large-scale industrial production of magnetic abrasive. 展开更多
关键词 iron-based SiC composite powder gas atomization and rapid solidification spherical composite magnetic abrasive magnetic abrasive finishing(MAF)
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Two-Body Abrasive Wear of the Surfaces of Pangolin Scales 被引量:13
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作者 Jin Tong Tie-biao Lu +3 位作者 Yun-hai Ma Heng-kun Wang Lu-quan Ren R. D. Arnell 《Journal of Bionic Engineering》 SCIE EI CSCD 2007年第2期77-84,共8页
The Pangolin, a soil-burrowing animal, is covered with scales. These scales are often abraded by soil and rock and their surface is corrugated. The abrasive wear of the surface of the scales was examined. The scales w... The Pangolin, a soil-burrowing animal, is covered with scales. These scales are often abraded by soil and rock and their surface is corrugated. The abrasive wear of the surface of the scales was examined. The scales were taken from a pangolin that had died of natural causes. The tests were run on a rotary disc abrasive wear tester. The abrasive material was quartz sand (96.5 wt.%) and bentonite (3.5 wt.%). The morphology of the abraded surfaces and the abrasion were examined by stereoscopic microscopy and scanning electron microscopy. The concepts are proposed of "Guiding-Effect" and "Rolling-Effect" on the textured surfaces under free abrasive wear conditions and the critical dimensions of the "Rolling-Effect" are discussed. 展开更多
关键词 pangolin scale surface morphology abrasive wear
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Multiphase Flow and Wear in the Cutting Head of Ultra-high Pressure Abrasive Water Jet 被引量:8
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作者 YANG Minguan WANG Yuli KANG Can YU Feng 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2009年第5期729-734,共6页
Abrasive water jet cutting technology is widely applied in the materials processing today and attracts great attention from scholars, but many phenomena concerned are not well understood, especially in the internal je... Abrasive water jet cutting technology is widely applied in the materials processing today and attracts great attention from scholars, but many phenomena concerned are not well understood, especially in the internal jet flow of the cutting head at the condition of ultra-high pressure. The multiphase flow in the cutting head is numerically simulated to study the abrasive motion mechanism and wear inside the cutting head at the pressure beyond 300 MPa. Visible predictions of the particles trajectories and wear rate in the cutting head are presented. The influences of the abrasive physical properties, size of the jewel orifice and the operating pressure on the trajectories are discussed. Based on the simulation, a wear experiment is carried out under the corresponding pressures. The simulation and experimental results show that the flow in the mixing chamber is composed of the jet core zone and the disturbance zone, both affect the particles trajectories. The mixing efficiency drops with the increase of the abrasive granularity. The abrasive density determines the response of particles to the effects of different flow zones, the abrasive with medium density gives the best general performance. Increasing the operating pressure or using the jewel with a smaller orifice improves the coherency of p articles trajectories but increases the wear rate of the jewel holder at the same time. Walls of the jewel holder, the entrance of the mixing chamber and the convergence part of the mixing tube are subject to wear out. The computational and experimental results give a qualitative consistency which proves that this numerical method can provide a reliable and visible cognition of the flow characteristics of ultra-high pressure abrasive water jet. The investigation is benefit for improving the machining properties of water jet cutting systems and the optimization design of the cutting head. 展开更多
关键词 abrasive water jet cutting head multiphase flow WEAR
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Effects of nano-Al_2O_3 and nano-ZrO_2 on the microstructure, behavior and abrasive wear resistance of WC-8Co cemented carbide 被引量:7
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作者 YANG Tian'en XIONG Ji SUN Lan GUO Zhixing QIN Kangcai 《Rare Metals》 SCIE EI CAS CSCD 2011年第5期533-538,共6页
WC-8wt.% Co cemented carbides with varied nano-Al 2 O 3 and nano-ZrO 2 contents were prepared respectively following conventional powder metallurgical procedures. Effects of nano-Al 2 O 3 and nano-ZrO 2 on the microst... WC-8wt.% Co cemented carbides with varied nano-Al 2 O 3 and nano-ZrO 2 contents were prepared respectively following conventional powder metallurgical procedures. Effects of nano-Al 2 O 3 and nano-ZrO 2 on the microstructure, behavior, and abrasive wear resistance were investigated. The result shows that a finer and more homogenous microstructure can be achieved by increasing nano-Al 2 O 3 , and increasing nano-ZrO 2 makes the microstructure more refined. Nano-Al 2 O 3 and nano-ZrO 2 could both help to give increased hardness. Transverse rupture strength is higher if the above nano-oxides are doped appropriately, whereas excess addition is deleterious. Abrasive wear resistance presents different variations with respect to increasing nano-Al 2 O 3 and nano-ZrO 2 . By contrast, increasing nano-ZrO 2 enhances the abrasive wear resistance more effectively than increasing nano-Al 2 O 3 . The influence of the two nano-oxides contents on the abrasive wear resistance does not almost vary with wear time, and the optimum addition level of nano-Al 2 O 3 in WC-8% Co cemented carbide is 0.3 wt.% from the stand of abrasive wear resistance. In addition, both of the nano-oxides can retard the increase of wear rate in long-term abrasive wear. 展开更多
关键词 cemented carbides MICROSTRUCTURE abrasION wear resistance OXIDES mechanical properties
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Chemical Mechanical Polishing of Glass Substrate with α-Alumina-g-Polystyrene Sulfonic Acid Composite Abrasive 被引量:9
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作者 LEI Hong BU Naijing ZHANG Zefang CHEN Ruling 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2010年第3期276-281,共6页
Abrasive is the one of key influencing factors during chemical mechanical polishing(CMP) process. Currently, α-Alumina (α-Al2O3) particle, as a kind of abrasive, has been widely used in CMP slurries, but their h... Abrasive is the one of key influencing factors during chemical mechanical polishing(CMP) process. Currently, α-Alumina (α-Al2O3) particle, as a kind of abrasive, has been widely used in CMP slurries, but their high hardness and poor dispersion stability often lead to more surface defects. After being polished with composite particles, the surface defects of work pieces decrease obviously. So the composite particles as abrasives in slurry have been paid more attention. In order to reduce defect caused by pure α-Al2O3 abrasive, α-alumina-g-polystyrene sulfonic acid (α-Al2O3-g-PSS) composite abrasive was prepared by surface graft polymerization. The composition, structure and morphology of the product were characterized by Fourier transform infrared spectroscopy(FTIR), X-ray photoelectron spectroscopy(XPS), time-of-flight secondary ion mass spectroscopy(TOF-SIMS), and scanning electron microscopy(SEM), respectively. The results show that polystyrene sulfonic acid grafts onto α-Al2O3, and has well dispersibility. Then, the chemical mechanical polishing performances of the composite abrasive on glass substrate were investigated with a SPEEDFAM-16B-4M CMP machine. Atomic force microscopy(AFM) images indicate that the average roughness of the polished glass substrate surface can be decreased from 0.835 nm for pure α-Al2O3 abrasive to 0.583 nm for prepared α-Al2O3-g-PSS core-shell abrasive. The research provides a new and effect way to improve the surface qualities during CMP. 展开更多
关键词 chemical mechanical polishing glass substrate α-alumina graft polymerization composite abrasive
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DEM Numerical Simulation of Abrasive Wear Characteristics of a Bioinspired Ridged Surface 被引量:10
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作者 Mohammad Almagzoub Mohammad Carlo Menon 《Journal of Bionic Engineering》 SCIE EI CSCD 2010年第2期175-181,共7页
This paper presents numerical investigations into a ridged surface whose design is inspired by the geometry of a Farrer’sscallop.The objective of the performed research is to assess if the proposed Bioinspired Ridged... This paper presents numerical investigations into a ridged surface whose design is inspired by the geometry of a Farrer’sscallop.The objective of the performed research is to assess if the proposed Bioinspired Ridged Surface (BRS) can potentiallyimprove wear resistance of soil-engaging components used in agricultural machinery and to validate numerical simulationsperformed using software based on the Discrete Element Method (DEM).The wear performance of the BRS is experimentallydetermined and also compared with a conventional flat surface.Different size of soil particles and relative velocities between theabrasive sand and the testing surfaces are used.Comparative results show that the numerical simulations are in agreement withthe experimental results and support the hypothesis that abrasive wear is greatly reduced by substituting a conventional flatsurface with the BRS. 展开更多
关键词 bioinspired ridged surface abrasive wear numerical simulation Discrete Element Method (DEM)
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Research on Abrasives in the Chemical Mechanical Polishing Process for Silicon Nitride Balls 被引量:6
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作者 YUAN Ju-long, Lü Bing-hai, LIN Xü, JI Shi-ming, ZHANG Li-bin (Mechanical and Electronic Engineering College, Zhejiang University of Technology, Hangzhou 310014, China) 《厦门大学学报(自然科学版)》 CAS CSCD 北大核心 2002年第S1期63-64,共2页
Silicon nitride (Si 3N 4) has been the main material for balls in ceramic ball bearings, for its lower density, high strength, high hardness, fine thermal stability and anticorrosive, and is widely used in various fie... Silicon nitride (Si 3N 4) has been the main material for balls in ceramic ball bearings, for its lower density, high strength, high hardness, fine thermal stability and anticorrosive, and is widely used in various fields, such as high speed and high temperature areojet engines, precision machine tools and chemical engineer machines. Silicon nitride ceramics is a kind of brittle and hard material that is difficult to machining. In the traditional finishing process of silicon nitride balls, balls are lapped by expensive diamond abrasive. The machining is inefficiency and the cost is high, but also lots of pits, scratch subsurface micro crazes and dislocations will be caused on the surface of the balls, the performance of the ball bearings would be declined seriously. In these year, a kind of new technology known as chemical mechanical polishing is introduced in the ultraprecision machining process of ceramic balls. In this technology, abrasives such as ZrO 2, CeO 2 whose hardness is close to or lower than the work material (Si 3N 4) are used to polishing the balls. In special slurry, these abrasives can chemo-mechanically react with the work material and environment (air or water) to generate softer material (SiO 2). And the resultants will be removed easily at 0.1 nm level. So the surface defects can be minimized, very smooth surface (Ra=4 nm) and fine sphericity (0.15~0.25 μm ) can be obtained, and the machining efficiency is also improved. The action mechanism of the abrasives in the chemical mechanical polishing process in finishing of silicon nitride ball will be introduced in this paper. 展开更多
关键词 silicon nitride ball chemical mechanical polishing abrasiveS
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THE EROSIVE PROCESS IN ABRASIVE WATERJET CUTTING OF POLYMER MATRIX COMPOSITES 被引量:3
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作者 J.Wang School of Mechanical, Manufacturing and Medical Engineering, Queensland University of Technology, GPO Box 2434, Brisbane, Qld. 4001, Australia 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 1999年第5期886-890,共5页
A study is carried out which analyzes the machinability of polymer matrix composites under an abrasive waterjet (AWJ) and the associated erosive process or mechanism. It shows that AWJ cutting can produce good quality... A study is carried out which analyzes the machinability of polymer matrix composites under an abrasive waterjet (AWJ) and the associated erosive process or mechanism. It shows that AWJ cutting can produce good quality kerf at high production rate if the cutting parameters are properly selected. A scanning electron microscopy (SEM) analysis of the cut surfaces reveals that the erosive process for the matrix material (resin) involves shearing and ploughing as well as intergranular cracking, while shearing is a dominant process for cutting the fibres in the upper cutting region but the fibers are mostly pulled out in the lower region. 展开更多
关键词 abrasive waterjet COMPOSITE materials EROSIVE PROCESS MACHINABILITY
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Stability analyses of the mass abrasive projectile high-speed penetrating into concrete target. Part Ⅱ: Structural stability analyses 被引量:5
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作者 Hao Wu Xiao-Wei Chen +1 位作者 Qin Fang Li-Lin He 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2014年第6期943-955,共13页
The initial oblique and attacking angles as well as the asymmetrical nose abrasion may lead to bending or even fracture of a projectile,and the penetration efficiency decreases distinctly.The structural stability of a... The initial oblique and attacking angles as well as the asymmetrical nose abrasion may lead to bending or even fracture of a projectile,and the penetration efficiency decreases distinctly.The structural stability of a high-speed projectile non-normally penetrating into concrete and the parametric influences involved are analyzed with the mass abrasion taken into account.By considering the symmetrical or asymmetrical nose abrasion as well as the initial oblique and attacking angles,both the axial and the transverse drag forces acting on the projectile are derived.Based on the ideal elastic-plastic yield criterion,an approach is proposed for predicting the limit striking velocity(LSV)that is the highest velocity at which no yielding failure has occurred and the projectile can still maintain its integral structural stability.Furthermore,some particular penetration scenarios are separately discussed in detail.Based on the engineering model for the mass loss and nose-blunting of ogive-nose projectiles established in Part I of this study,the above approach is validated by several high-speed penetration tests.The analysis on parametric influences indicates that the LSV is reduced with an increase in the asymmetrical nose abrasion,thelength-diameter-ratio,and the concrete strength,as well as the oblique and attacking angles.Also,the LSV raises with an increase in the initial caliber-radius-head(CRH)and the dimensionless cartridge thickness of a projectile. 展开更多
关键词 PROJECTILE High-speed penetration Concrete Oblique angle Attacking angle Asymmetrical nose abrasion
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Influence of abrasive hardness on erosion wear of abrasive air jets 被引量:7
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作者 LIU Yong CHEN Chang-jiang +2 位作者 WEI Jian-ping LIU Xiao-tian WANG Xiang-dong 《Journal of Central South University》 SCIE EI CAS CSCD 2020年第2期356-371,共16页
To make clear the influence of abrasive hardness on the erosion effect,the erosion experiments of abrasive air jet with the same impact energy were carried out.The influence of abrasive hardness on the erosion effect ... To make clear the influence of abrasive hardness on the erosion effect,the erosion experiments of abrasive air jet with the same impact energy were carried out.The influence of abrasive hardness on the erosion effect is clarified by comparing the different erosion depths.The main conclusions are as follows.Under the same mass flow rate and mesh number,the abrasive with a higher density needs greater pressure irrespective of hardness.After erosion damage,the abrasive size exhibits a Weibull distribution.The shape parameterβand Weibull distribution function of four types of abrasives are derived by the least squares method;moreover,βis found to have a quadratic relation with abrasive hardness.The results of the erosion experiments show that abrasive hardness and erosion depth are quadratically related.By calculating the increase in surface energy after abrasive erosion crushing,it is found that abrasive hardness has a quadratic relation with surface energy and that the increases in erosion depth and surface energy consumption are basically identical.In conclusion,the effect is a soft abrasive impact when the ratio of abrasive hardness(Ha)to the material hardness(Hm)is<2.6,and it is a hard abrasive impact when Ha/Hm>3. 展开更多
关键词 abrasive air jet abrasive hardness rock erosion abrasive size distribution coal bed methane
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TBM tunneling in extremely hard and abrasive rocks:Problems,solutions and assisting methods 被引量:30
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作者 ZHENG Yan-long HE Lei 《Journal of Central South University》 SCIE EI CAS CSCD 2021年第2期454-480,共27页
Extremely hard and abrasive rocks pose great challenges to the past and ongoing TBM projects by increasing cutter wear and reducing penetration rates.A considerable amount of research has been conducted to improve the... Extremely hard and abrasive rocks pose great challenges to the past and ongoing TBM projects by increasing cutter wear and reducing penetration rates.A considerable amount of research has been conducted to improve the performance of TBMs in those challenging grounds by either improving the capacity of TBMs or developing assisting rock breakage methods.This paper first highlights the challenges of hard and abrasive rocks on TBM tunneling through case studies.It then presents the development of hard rock TBMs and reviews the technologies that can be used individually or as assistance to mechanical excavators to break hard rocks.Emphases are placed on technologies of high pressure waterjet,laser and microwave.The state of the art of field and laboratory research,problems and research directions of those technologies are discussed.The assisting methods are technically feasible;however,the main challenges of using those methods in the field are that the energy consumption can be over 10 times high and that the existing equipments have robustness problems.More research should be conducted to study the overall energy consumption using TBMs and the assisting methods.Pulsed waterjet,laser and microwave technologies should also be developed to make the assistance economically viable. 展开更多
关键词 hard and abrasive rocks tunnel boring machine waterjet laser microwave
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Improved Soft Abrasive Flow Finishing Method Based on Turbulent Kinetic Energy Enhancing 被引量:8
20
作者 Jun LI Shiming JI Dapeng TAN 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2017年第2期301-309,共9页
Soft abrasive flow(SAF) finishing can process the irregular geometric surfaces, but with the matter of low processing efficiency. To address the issue, an improved SAF finishing method based on turbulent kinetic ene... Soft abrasive flow(SAF) finishing can process the irregular geometric surfaces, but with the matter of low processing efficiency. To address the issue, an improved SAF finishing method based on turbulent kinetic energy enhancing is proposed. A constrained flow passage with serration cross-section is constructed to increase the turbulence intensity. Taking the constrained flow passage as the objective, a two-phase fluid dynamic model is set up by using particle trajectory model and standard k-ε turbulence model, and the flow field characteristics of the flow passage are acquired. The numerical results show that the serration flow passage can enhance the turbulence intensity, uniform the particles distribution, and increase the particle concentration near the bottom wall. The observation results by particle image velocimetry(PIV) show that the internal vortex structures are formed in flow passage, and the abrasive flow takes on turbulence concentrating phenomenon in near-wall region. The finishing experiments prove that the proposed method can obtain better surface uniformity, and the processing efficiency can be improved more 35%. This research provides an abrasive flow modeling method to reveal the particle motion regulars, and canoffer references to the technical optimization of fluid-based precision processing. 展开更多
关键词 Soft abrasive flow Serration flow passage ·Kinetic energy enhancing Particle image velocimetry
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