Дисертації: "Mechanical grinding"

1

Brown, Austin (Austin R. ). "Axially force limited grinding spindle for robotic grinding." Thesis, Massachusetts Institute of Technology, 2018. http://hdl.handle.net/1721.1/119966.

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Thesis: S.B., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2018.
Cataloged from PDF version of thesis.
Includes bibliographical references (page 35).
Grinding and Polishing of small parts is often easily performed by human hands, yet is challenging to automate. The grinding and polishing process is best done using a force-control scheme, which human hands perform naturally. Heavy robotic arms, which favor a position-control scheme, are difficult to control precisely, and trajectory errors can cause excessive grinding force which leads to burning of the part or destruction of the grinding wheel. Prior art of direct force control on a large robot arm requires the end-effector to have a 6-axis dynamometer, which is unwieldy, costly, and greatly limits the speed/precision of the process. We will discuss a new type of grinding spindle which is axially compliant, allowing the position-control robot arm to be used in a force-control nature. The spindle has a disjoint force-displacement curve, effectively operating in two modes: position-control mode at first, until a critical force is exceeded, when the spindle transitions into force-mode, keeping constant grinding force on the part though a certain range of travel. This limits the amount of force which can be imparted during grinding to a safe amount. The spindle is very simple and mechanically robust. We have built this hybrid position-force control spindle and tested it. The spindle was shown to perform correctly and successfully completed the test grind.
by Austin Brown.
S.B.

2

Curtis, David Thomas. "Point grinding and electrolytic point grinding of Udimet 720." Thesis, University of Birmingham, 2011. http://etheses.bham.ac.uk//id/eprint/2850/.

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The work within this Thesis is concerned with the manufacturing processes associated with the production of blade root mounting slots in aeroengine compressor and turbine discs. Typically slots are of dovetail or fir-tree geometry dependent on specific design requirements. The state of the art process across the industry is broaching however, despite achieving required geometrical tolerances and surface integrity for decades the process is not without its disadvantages. Primarily these include the inflexibility of the process, machine tool cost; size and cutting forces, complexity of tooling and set up and further the limited level of control of the process beyond tooling design. This has led to research into alternative processes across a range of conventional and non-conventional manufacturing techniques. Work presented here focuses on two key technology areas, namely point grinding and electrolytic point grinding. The former applies small diameter single layer grinding wheels on a high speed machining centre with spindle capability in the region of 60,000rpm. Target geometry was a complex fir-tree root form requiring dimensional control to within +/- 5um and a surface integrity in line with critical aerospace components. The later process investigated the unification of point grinding and electrochemical machining on a vertical machining centre to assess process performance across a range of variables.

3

Levert, Joseph Albert. "Interface mechanics of chemical mechanical polishing for integrated circuit planarization." Diss., Georgia Institute of Technology, 1997. http://hdl.handle.net/1853/15914.

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4

Svensson, Dennis, and Svärd Tobias Falk. "Mechanical dry grinding process of saw chain." Thesis, Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-39927.

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The cutting links on chainsaws needs to be sharpened regularly to retain its sharpness. The most effective way is to use a machine wheel grinder. However, due to high friction there is a high risk of tempering the steel and damaging the sustainability to wear, resulting in a dull cutting edge. In order to develop a grinding method that produces a good result every time, a series of parameters were tested in order to determine which combination of these generated the best grinding results. With all parameters established the results shows that the attributes of each grinding wheel are the main parameter controlling the grinding result. This project investigates the attributes of different grinding wheels and their impact on grinding results. By comparing the energy each grinding wheel uses to perform the same amount of work, each grinding wheels suitability is rated based on its performance. The calculations and the results from the analyses and tests show which of the grinding wheels performed the work with the lowest amount of increased energy.

5

Baniszewski, Beth (Beth Ellen). "An environmental impact analysis of grinding." Thesis, Massachusetts Institute of Technology, 2005. http://hdl.handle.net/1721.1/32880.

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Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2005.
Includes bibliographical references (leaves 39-40).
This thesis was intended to investigate the environmental impact of grinding in the United States manufacturing industry. Grinding is an ideal method for producing parts with a fine surface finish and high dimensional accuracy and for shaping hard or brittle workpieces. There are a wide variety of different types of grinding machines, each with different applications and slightly different energy requirements. Workpieces are generally flooded with a stream of coolant while being ground or placed in a spray of coolant mist. Coolant recycling systems are used to filter ground off chips out of coolant and to remove foreign oils and bacteria which pose health hazards. Oil mist collectors both clean mist coolant and prevent the toxic coolant from being inhaled by machinists. In total, 63 *10¹⁵ joules of energy are consumed per year by grinding in manufacturing, 57% of which is directly used in material removal. A total of 1.5*10¹⁰ pounds of scrap chips, spent grinding wheels, and used filters are produced each year as a result of grinding, over 99% of that being scrap chips. About 2.3 million gallons of fluids per year of grinding fluids are incinerated. Grinding creates a significant environmental footprint, creating a need for methods to reduce energy use in grinding and for ways to recycle solid waste that would otherwise be sent to landfills or incinerated.
by Beth Baniszewski.
S.B.

6

Zhang, Xiaohong. "Chemical mechanical polishing and grinding of silicon wafers." Diss., Manhattan, Kan. : Kansas State University, 2007. http://hdl.handle.net/2097/475.

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7

Brown, Matthew Lasché. "Intelligent robot grinding : planning, optimization, and control." Thesis, Massachusetts Institute of Technology, 1988. http://hdl.handle.net/1721.1/14552.

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8

Ebbrell, Stephen. "Process requirements for precision grinding." Thesis, Liverpool John Moores University, 2003. http://researchonline.ljmu.ac.uk/5633/.

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9

Scagnetti, Paul Albert. "Design of an industrial precision ceramic grinding machine." Thesis, Massachusetts Institute of Technology, 1996. http://hdl.handle.net/1721.1/10918.

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10

Shan, Lei. "Mechanical interactions at the interface of chemical mechanical polishing." Diss., Georgia Institute of Technology, 2000. http://hdl.handle.net/1853/17774.

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11

Agarwal, Reena. "Degradation of polymers in chemical mechanical polishing." Thesis, Georgia Institute of Technology, 2000. http://hdl.handle.net/1853/11828.

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12

Yin, Guoxu. "Theoretical-Experimental Study of Fluid Delivery and Heat Management in Grinding." University of Toledo / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1438598110.

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13

Goldfine, Neil. "Process analysis and design for grinding robot tool holders." Thesis, Massachusetts Institute of Technology, 1985. http://hdl.handle.net/1721.1/91315.

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14

Charmley, James E. (James Edward). "Geometric and dynamic analysis of shoe-type centerless grinding." Thesis, Massachusetts Institute of Technology, 1992. http://hdl.handle.net/1721.1/43242.

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15

Tate, Allan Robert. "Closed loop force control for a robotic grinding system." Thesis, Massachusetts Institute of Technology, 1986. http://hdl.handle.net/1721.1/15031.

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Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1986.
MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING
Bibliography: leaves 175-179.
by Allan Robert Tate.
M.S.

16

Mess, Francis McCarthy. "Wear model for chemo-mechanical polishing of single crystal silicon." Thesis, Georgia Institute of Technology, 1997. http://hdl.handle.net/1853/15984.

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17

Taylor, Andre D. "Chemical-mechanical planarization of lithium gallate." Thesis, Georgia Institute of Technology, 1999. http://hdl.handle.net/1853/12375.

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18

Bibler, Jared Evan. "Effects of imbalance and geometric error on precision grinding machines." Thesis, Massachusetts Institute of Technology, 1997. http://hdl.handle.net/1721.1/43428.

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19

Moeller, Gregory V. "Residual stresses due to grinding." Thesis, This resource online, 1995. http://scholar.lib.vt.edu/theses/available/etd-05022009-040807/.

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20

Li, Wenwu 1972. "Exploring the fundamentals of impact breakage events in grinding." Thesis, McGill University, 2005. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=98987.

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Grinding in mineral processing is used to liberate valuable minerals from ore and prepare feed for mineral separation. It accounts for up to 50% of a concentrator's energy consumption. Ball mills are usually adopted in grinding processes; however their energy efficiency is low. Consequently, a small improvement can lead to important savings.
Population balance models can be used for ball mill optimization, but their use is limited because they are black box models based on incomplete information about the breakage events inside ball mills. Charge motion simulators, based on the discrete element method (DEM), not only provide information about charge media motion, but also collision energy distributions inside ball mills. Ball mill optimization can be achieved using charge motion simulators if the product size distribution can be predicted by linking charge motion results with single particle breakage tests.
Single particle drop tests were carried out to determine the effect of different levels of impact energy. Fundamental ore breakage model equations for an impact breakage event were established, and were applied for the drop weight tests based on a theoretical breakage mechanism. The energy consumptions are calculated with the given feed and product size distribution with the established equations. The comparison of two kinds of drop weight test devices were made and the effect of impact speeds of drop blocks on particle breakage at constant impact energy level was also discussed.

21

Lin, Zhixin. "An investigation of temperature in form grinding." Thesis, Liverpool John Moores University, 1999. http://researchonline.ljmu.ac.uk/5062/.

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22

Jackson, Andrew. "An investigation of useful fluid flow in grinding." Thesis, Liverpool John Moores University, 2008. http://researchonline.ljmu.ac.uk/5860/.

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23

Gviniashvili, Vladimir. "Fluid application system optimisation for high speed grinding." Thesis, Liverpool John Moores University, 2003. http://researchonline.ljmu.ac.uk/5605/.

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24

Rhoney, Brian Keith. "Cylindrical Wire Electrical Discharge Truing of Metal Bond Diamond Grinding Wheels." NCSU, 2001. http://www.lib.ncsu.edu/theses/available/etd-20010404-133336.

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The goal of this research was to use the wire Electrical Discharge Machining (EDM) to profile a metal bond diamond grinding wheel, and then study the wear and grinding performance of the EDM trued wheel. Diamond wheels are known to exhibit low wheel wear for precision grinding of ceramics but create difficulty in creating precision trued forms. With the increased use of hard engineering ceramics in mechanical design, new methods of truing these wheels had to be investigated. In profiling a vitrified bond diamond wheel, a Computer Numerically Controlled (CNC) single point diamond or a diamond crush roll is often used. However, due to the high strength of the metal bond matrix, these methods cannot be implemented with a metal bond diamond wheel. Instead of applying a mechanical force, Wire Electrical Discharge Truing (WEDT) process utilizes electrical sparks to erode the metal matrix, which allows the non-conductive diamonds to simply fall away. A precision spindle was first built to rotate the wheel inside a traditional wire EDM machine. Once the process proved feasible, grinding studies were developed to compare the performance of a WEDT wheel against a diamond rotary trued/stick dressed wheel. Grinding force, surface finish of the ground silicon nitride parts, and wheel wear were all examined. The surfaces of both truing methods were compared using Stereo-Scanning Electron Microscopy to measure the protruding diamonds' height and identify the wear mechanism. Result of the research shows promise for the future use of WEDT as a truing method for metal bond wheels.

25

Chen, Xun. "Strategy for the selection of grinding wheel dressing conditions." Thesis, Liverpool John Moores University, 1995. http://researchonline.ljmu.ac.uk/4948/.

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26

Qi, Hongsheng. "A contact length model for grinding wheel-workpiece contact." Thesis, Liverpool John Moores University, 1995. http://researchonline.ljmu.ac.uk/5134/.

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27

Srinivasaraghavan, Madhusudhanan. "Experimental and theoretical investigation of force distribution in the grinding contact zone." Thesis, McGill University, 2009. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=40810.

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An experimental approach and an analytical procedure have been developed for the prediction of the force distribution in the grinding wheel and the workpiece contact zone. Additionally, a numerical analysis using finite element methods was carried out to verify the force distribution in the actual grinding cases. This work was motivated by the need to obtain the maximum force acting on individual active abrasive grains for establishing the probability of grain fracture and pullouts due to this force. In the experimental approach, forces were measured while grinding small segments of the full wheel-workpiece contact length. The measured forces were used to predict the forces corresponding to smaller segments of the full contact arc to obtain the force distribution. To illustrate the method, forces were measured for four different grinding conditions using a 60 grit CBN grinding wheel with a small segment of the nickel alloy (IN718) workpiece. The predicted force distributions were found to increase at a decreasing rate from the bottom to the top of the contact arc in all four cases. Further the force distributions were applied to predict the transient grinding power. The predicted power values were found to match very well with the measured values in all four cases. For the analytical prediction of the force distribution, a CBN grinding wheel and the workpiece were modeled using Solidworks, and the interaction between abrasive grains and the workpiece were simulated individually for a few revolutions of the wheel to predict the uncut chip geometries. The forces corresponding to the active grains in the contact arc were calculated from the uncut chip geometries, using which the force distributions were predicted. The predicted force distributions from the analytical and the experimental techniques were found to match very well. Furthermore, using DEFORM 3D, numerical analyses were carried out on single grain and multiple grains grinding cases to predict the for
Une approche expérimentale et une procédure analytique ont été développés pour la prédiction de la répartition de la force dans la meule et zone de contact de la pièce. En outre, un calcul numérique utilisant les méthodes des éléments finis a été réalisée pour vérifier la répartition de la force, dans le cas de broyage. Ce travail a été motivée par la nécessité d'obtenir la force maximale agissante sur les grains abrasifs actifs pour établir la probabilité de rupture du grain et pullouts en raison de cette force. Dans l'approche expérimentale, les forces ont été mesurées lors du meulage d’un petit segment de la roue longueur de contacte entre la meule et la pièce. Les forces mesurées ont été utilisées pour prédire les forces correspondantes à des segments plus petits que les coordonnées complètes de l'arc de contact pour obtenir la répartition. Pour illustrer la méthode, les forces ont été mesurées pour quatre conditions de broyage en utilisant du sable de 60 meules CBN avec un petit segment d’un pièce de l'alliage de nickel (IN718) pièce. Les prévisions de répartition de la force a été constaté à augmenter à un taux décroissant du bas vers le haut de l'arc de contact dans les quatre cas. En outre, les prévisions de répartition de la force a été appliquée pour prédire le pouvoir transitoire de broyage. La puissance prédit a éte trouvée qui corresponde très bien à la puissance mesurée dans les quatre cas. Pour la prévision analytique de la répartition de la force, typique meules CBN et la pièce ont été modelée en utilisant Solidworks, et l'interaction entre chaque grain abrasif sur la meule et la pièce a été simulée individuellement pour quelques révolutions de la meule pour prédire les géométries des coupeaux non coupés pour deux des quatre conditions expérimentales de broyage. Sur la base de ces géométries des coupaux non coupés la force correspondante à chaque grain dans l

28

Tyabashe, Loyiso. "Determination of the power losses on a tyre-mounted ore-grinding mill." Master's thesis, University of Cape Town, 1998. http://hdl.handle.net/11427/9709.

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The objective of this study was to determine the power losses occurring on a tyre-mounted ore-grinding mill designed by Dorbyl Heavy Engineering for Mintek. In order to understand the type of losses occurring on this mill it was decided that a scaled model be built and tested. Such a model mill was designed through the dimensional analysis and similitude technique. This technique enables the reduction of the number of variables to be tested by grouping them into a set of dimensionless parameters, and also allows the results obtained by means of experimentation with the scaled models to be related to the full-scale prototypes. The model mill was constructed in the Mechanical Engineering Workshop at the University of Cape Town. The overall dimensions of the model are 1400 mm long, 1070 mm wide and 892.5 mm high. Its drive-train comprises an electric motor, the wedge and timing belts with the appropriate pulleys, a differential gear set, the tyres, a shell and a disc brake sub-assembly. The tyres used to drive the shell can either be of the pneumatic or solid rubber types. The model mill was designed such that the tyre parameters required in the theoretical solution for power losses, which utilises the Light Vehicle Dynamics Simulation tyre model, could also be measured.

29

Campbell, William Jarrett. "Model predictive run-to-run control of chemical mechanical planarization /." Digital version accessible at:, 1999. http://wwwlib.umi.com/cr/utexas/main.

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30

Mohammed, Arif. "Applying laser irradiation and intelligent concepts to identify grinding phenomena." Thesis, University of Nottingham, 2012. http://eprints.nottingham.ac.uk/12675/.

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The research discussed in this thesis explores a new method for the detection of grinding burn temperature using a laser irradiation acoustic emission (AE) sensing technique. This method is applicable for the grinding process monitoring system, providing an early warning for burn detection on metal alloy based materials (specifically nickel alloy based materials: Inconel718 and MarM002). The novelty in this research is the laser irradiation induced thermal AE signal that represents the grinding thermal behaviour and can be used for grinding burn detection. A set of laser irradiation experiments were conducted to identify key process characteristics. By controlling the laser power, the required grinding temperatures were simulated on alloy test materials. The thermal features of the extracted AE signal were used to identify the high, medium and low temperature signatures in relation to the off-focal laser distances. Grinding experiments were also conducted to investigate burn conditions. The extracted AE data was used to identify grinding burn and no burn signatures in relation to the depth of cuts. A new approach using an artificial neural network (ANN) was chosen as the pattern recognition tool for classifying grinding burn detection and was used to classify grinding temperatures by extracting the mechanical-thermal grinding AE signal. The results demonstrated that the classification accuracy achieved was 66 % for Inconel718 and 63 % for MarM002 materials. The research established that the wheel wear has a large influence on the creation of burn within the workpiece surface. The results demonstrated that the AE signals in each grinding trial presents different levels of high, medium and low temperature scales. This type of information provides a foundation for a new method for monitoring of grinding burn and wheel wear.

31

Razavi, H. Ali. "Identification and control of grinding processes for intermetalic [sic] compunds [sic]." Diss., Georgia Institute of Technology, 2000. http://hdl.handle.net/1853/18917.

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32

Alqahtani, Bader. "Examination of Oxidation Sites for Electrolytic In-Process Dressing (ELID) Grinding using SEM." University of Toledo / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1556841748381472.

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33

Barczak, Lukasz. "Application of Minimum Quantity Lubrication (MQL) in plane surface grinding." Thesis, Liverpool John Moores University, 2010. http://researchonline.ljmu.ac.uk/5935/.

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The aim of this research was to acquire and formalise understanding of the Minimum Quantity Lubrication (MQL) technique in the surface grinding operation. The investigation aimed to show through experiment and theoretical study the effects of MQL on grinding process performance, measured in terms of tangential and normal forces, temperature and surface finish. A comparison of conventional, dry and MQL fluid delivery methods was performed. The experimental study was undertaken on a CNC grinding machine with integrated monitoring. A Taguchi methodology was employed to provide qualitative evidence of the strength of process parameters on performance indicators. The usefulness and promise of MQL was established. The study identified regimes of grinding where MQL can be employed successfully. This outcome is supported by results showing, in some applications, that MQL is comparable in performance to grinding under conventional fluid delivery. It was found that for some conditions MQL outperformed conventional fluid delivery. This was particularly so in the case of the tests with material EN8, (approximately 32 HRQ), where MQL was found to outperform conventional fluid delivery in almost all measures. As expected, not all conditions were in favour of MQL delivery and the reasons for this are discussed in detail in the thesis. A theoretical explanation for the efficient process performance is developed in relation to the experimental results obtained. The effects of variables such as DOC, dressing conditions, wheel speeds, workpiece speed and workpiece material are considered. It is reasoned that the MQL technique achieves efficient performance due to effective lubrication and effective contact region penetration by the fluid. Effective lubrication conditions were confirmed by highly competitive specific energy and grinding force measurements.

34

Opoz, Tahsin Tecelli. "Investigation of material removal mechanism in grinding : a single grit approach." Thesis, University of Huddersfield, 2012. http://eprints.hud.ac.uk/id/eprint/17818/.

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This thesis has investigated material removal mechanisms in grinding by considering single grit workpiece interaction. The investigation was performed both experimentally and using finite element simulation. Rubbing, ploughing and cutting mechanisms occurring during the grinding process were studied at the micro scale. Due to its nature the rubbing phase occurs in a very narrow region of grit-workpiece engagement and is difficult to examine under a microscope and so was investigated using FEM simulation. The ploughing mechanism was thoroughly investigated using both experimental tests and FEM simulations, and a similar trend was observed for the pile up ratio along the scratch path from the experimental tests and the FEM simulations. Ploughing and cutting mechanisms in grinding were found to be highly influenced by grit cutting edge shape, sharpness and bluntness. Cutting is the prominent mechanism when the grit cutting edge is sharp, but ploughing is more prominent when the grit cutting edge becomes flattened. In the case of multiple edges scratch formation, ploughing is dramatically increased compared to single edge scratches. Feasibility of ground surface simulation using FEM is demonstrated using multiple pass scratch formation in a cross direction. Although chip formation mechanism is developed at a relatively higher depth of cut (greater than 10 μm), at small scales down to 1 μm, FEM simulation was not a suitable method to use. To reduce the drawbacks of FEM simulation in micro scale cutting, a meshless simulation technique such as smooth particle hydrodynamics is recommended for future studies.

35

Bhaduri, Debajyoti. "Ultrasonic assisted creep feed grinding and dressing of advanced aerospace alloys." Thesis, University of Birmingham, 2014. http://etheses.bham.ac.uk//id/eprint/5415/.

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The research involves the investigation of hybrid ultrasonic assisted creep feed grinding (UACFG) of advanced aeroengine alloys, in particular Inconel 718, CMSX-4 and gamma titanium aluminide (γ-TiAl). For tests with ultrasonic vibration, workpieces were actuated at a constant frequency (~20kHz) via a specially designed block sonotrode attached to a 1kW piezoelectric transducer-generator system. The trials on nickel based superalloys were carried out using open structured alumina wheels whereas γ-TiAl specimens were machined with conventional silicon carbide and single layer diamond superabrasive wheels. Statistically designed experiments involving variation in wheel speed, table speed, depth of cut, grinding condition and vibration amplitude were employed in mainstream testing. Reductions in grinding force components were typically observed albeit at the cost of higher wheel wear and surface roughness of the ground slots when ultrasonic assisted grinding of nickel alloys. Conversely, UACFG of γ-TiAl exhibited lower grinding wheel wear and workpiece surface roughness. Surfaces ground with the assistance of vibration generally revealed greater side flow/ploughing and overlapping grit marks in comparison to standard creep feed ground specimens. Three dimensional topographic measurement of grinding wheel surface replicas indicated that ultrasonic vibration led to an increase in the number of active cutting points on the wheel.

36

Tsiakoumis, Vaios I. "An investigation into vibration assisted machining : application to surface grinding processes." Thesis, Liverpool John Moores University, 2011. http://researchonline.ljmu.ac.uk/6113/.

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The purpose of this study was to apply vibrations to the workpiece during surface grinding in order to improve the performance of the process. In addition to this, further necessary parameters were examined and analysed. A first step was to design the vibrating rig and after a number of different designs the most suitable model was selected for the conduction of the preliminary studies. However, a novel-improved system was designed and manufactured in order to undertake the full volume of experimental work. A number of simulations including stress and modal analysis were carried out and all the static and dynamic characteristics of the rigs were identified. Moreover, the exact dynamic behaviour of the rigs - including their natural frequencies - was established though real experiments. Sweep - sine and impact tests were employed in order to identify these dynamic parameters and the results were compared to those of simulation with the intention to detect the amount of error between these techniques. The rigs were vibrated at their resonant frequencies in order to achieve high values of amplitude with low voltage input. The static and dynamic characteristics of the grinding machine tool were identified. Similar methods such as sweep-sine test were employed in order to find the natural frequency of the machine tool's spindle unit. Static and dynamic stiffness of the machine tool's spindle unit as well as its compliance were identified. The preliminary studies showed an improvement in surface quality of the workpiece as well as a small reduction in cutting forces. This reduction was getting bigger with the increase of depth of cut. The main body of experimental work followed and showed that for 25 urn depths of cut, the vibration-assisted method could decrease up to 22.5 % the tangential forces. Furthermore, the effect of vibration was getting more noticeable at higher wheelspeeds and workspeeds. At those speeds the reduction in workpiece surface roughness reached 12.6%. Moreover, it was found that the application of vibration increased the material removal rate, reduced the cutting forces, increased the G-ratio and produced lower values of wheel wear compared to conventional grinding. Finally, an innovative closed-loop vibration control system was used for the process which could control the amplitude and the frequency of vibration in the actual grinding cycle. This I A Abstract system managed to control the applied values of vibration amplitude at resonant or near resonant frequencies. It was found that for higher depths of cut the closed-loop vibration control reduced the normal forces by 19% compared to open-loop control and 21 % compared to conventional grinding. Furthermore, the closed-loop control system performed better in terms of workpiece surface quality when grinding mild steel compared to conventional grinding and open-loop vibration control.

37

Guo, Lei. "Ultraviolet Bonding of Diamond Abrasive Tools for Lap-Grinding Process." University of Toledo / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1354572460.

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38

Powell, Malcolm S. "A study of charge motion in rotary mills, with particular reference to the grinding action." Doctoral thesis, University of Cape Town, 1993. http://hdl.handle.net/11427/9657.

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Анотація:

Includes bibliographical references.
The objective of this study was to develop a fundamental understanding of the action of the grinding charge in a mill, and to then correlate this with the metallurgical performance of different mill-liners. To achieve these overall objectives it was first necessary to develop suitable experimental techniques, and the development of these techniques became a large part of the objective of the study. The motion of balls deep within the charge of a rotary grinding mill was investigated. Novel investigative techniques were used to track the motion of the balls, including X-ray filming at 50 frames per second of both the front and side views of a transparent mill, and gamma-camera filming of a radioactive ball. Analysis of the trajectories of the balls revealed several phenomena in the milling action that have not been reported until now. It was observed that the paths of the balls are smooth, that they spiral in and out of the charge, and that the grinding does not take place by rotary nipping of the ore between the balls.

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Baines-Jones, Vadim Alexis. "Nozzle design for improved useful fluid flow in grinding." Thesis, Liverpool John Moores University, 2010. http://researchonline.ljmu.ac.uk/5929/.

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Khoshaim, Ahmed Bakr. "Single Side Electrolytic In-Process Dressing (ELID) Grinding with Lapping Kinematics of Silicon Carbide." University of Toledo / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1396269180.

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Bafakeeh, Omar T. "Micro/Nano Surface Finish Single Side Electrolytic In-Process Dressing (ELID) Grinding with Lapping Kinematics of Sapphire." University of Toledo / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1491948412941004.

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Mihic, Stefan Dragoljub. "CFD Investigation of Metalworking Fluid Flow and Heat Transfer in Grinding." University of Toledo / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1302189719.

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Pourghahramani, Parviz. "Mechanical activation of hematite using different grinding methods with special focus on structural changes and reactivity /." Luleå : Luleå University of Technology, 2007. http://epubl.ltu.se/1402-1544/2007/08/.

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Ng, Sum Huan. "Measurement and modeling of fluid pressures in chemical mechanical polishing." Diss., Available online, Georgia Institute of Technology, 2005, 2005. http://etd.gatech.edu/theses/available/etd-03022005-142857/unrestricted/ng%5Fsumhuan%5F200505%5Fphd.pdf.

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Анотація:

Thesis (Ph. D.)--Mechanical Engineering, Georgia Institute of Technology, 2005.
Steven Danyluk, Committee Chair ; Richard Salant, Committee Member ; Jeffrey Streator, Committee Member ; Michael Sacks, Committee Member ; Dennis Hess, Committee Member ; Leonard Borucki, Committee Member. Includes bibliographical references.

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Milner, Andrew Leigh. "The prediction of the outermost trajectory of media in a grinding mill for lifter bars with rounded or worn profiles." Master's thesis, University of Cape Town, 1997. http://hdl.handle.net/11427/21702.

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This thesis presents the analysis of the path of a ball on the inside of a ball mill for lifter bars with rounded or worn profiles. The model predicts the response of a single ball with particular reference to the balls trajectory after departure from the lifter bar and incorporates the effect of friction, mill rotational speed, lifter height as well as different lifter bar profiles. The out of plane travel of the particles are ignored and hence the system is reduced to a two dimensional problem. A set of experiments were performed on a model perspex mill in order to obtain data by which the theory could be compared. The lifter bar is analysed using a parabolic expression which allows the shape to be changed to model various stages oflifter wear. Two possible formulations are investigated in determining the motion of the particle on the lifter bar. The first formulation assumes the ball to roll on the lifter bar until a limiting friction is reached after which the ball will slide along the lifter. The second formulation considers the ball to have a pure sliding motion on the lifter.

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Wu, Hui. "Investigation of fluid flow in grinding using LDA techniques and CFD simulation." Thesis, Liverpool John Moores University, 2009. http://researchonline.ljmu.ac.uk/5944/.

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This research aimed to establish the requirements for effective fluid flow in grinding and to improve the efficiency of the fluid delivery system (fluid delivery optimization). Highly efficient fluid delivery will lower grinding temperatures, reduce the risk of thermal damage and reduce wheel wear. The thesis describes the work completed in the investigation of the complex fluid flow that occurs in the region close to the grinding contact zone between the wheel and workpiece and the boundary layer phenomena around the periphery of the rotating grinding wheel. Studies on air scraper and shoe nozzle application are also presented. Laser Doppler Anemometry (LDA) was employed to obtain a basic understanding of the flow velocity profile in the region close to the grinding contact zone in a low speed grinding system and key characteristics of the fluid flow under varying grinding conditions were identified. The mathematical formulae describing the air velocity distribution around the wheel have been derived from theory based on Newton's laws. Air boundary layer flow around the rotating grinding wheel was studied using LDA measurements and Computational Fluid Dynamics (CFD) simulation to get the air velocity distribution in varying conditions. The experimental results and the investigation made clear the contradictory knowledge relative to this issue and gave a full understanding of the air boundary layer flow. Air scrapers are used to reduce the effects of the air boundary layer. The effects of the size and position of the different scrapers on the air flow velocity and pressure distribution was investigated using CFD simulation. The research work provides a comprehensive assessment of the ability of the air scraper to reduce the intensity of the air boundary layer. The upper surface of the shoe nozzle can be regarded as an air scraper used to interrupt the air flow. Three different shoe nozzles were applied to investigate the fluid delivery situation using CFD simulation. Results from preliminary studies are presented for the shoe nozzle application. The effects of input fluid velocity, gap size and wheel speed on the pressure distribution along the arc of the gap are reported.

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Griffin, James. "Pattern recognition of micro and macro grinding phenomenon with a generic strategy to machine process monitoring." Thesis, University of Nottingham, 2008. http://eprints.nottingham.ac.uk/10487/.

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Abstract In modern manufacturing environments waste is an issue of great importance. Specifically the research in this thesis looks at issues in establishing the initial steps to gain a generic process monitoring system that ensures that grinding is both optimised but not the determent where costly malfunctions mean the scrapping and re-melting of expensive quality intensive materials. The research conducted in this thesis investigates the process of cutting, ploughing and rubbing during single grit scratch tests. These investigations meant the correlation between physical material removal phenomenon and the emitted material dislocations gained from acoustic emission extraction. The initial work looked at different aerospace materials and the distinction of cutting, ploughing and rubbing during single grit radial scratch tests. This initial work provided novel results not seen in this area before and paved the way for more robust results in investigating the same phenomena during horizontal single grit scratch tests. This work provided more robust classification of cutting, ploughing and rubbing and transferred directly to grinding pass cuts from 1um and 0.1mm depth cuts respectively. In using robust classifiers such as the Neural Network and novel classifiers such as non-linear data paradigms, Fuzzy-c clustering with Genetic Algorithm optimisation, cutting, ploughing and rubbing phenomenon was investigated. These investigations showed that more cutting occurs when there is moreinteraction between grit and workpiece based on the increase depth of cut. Other thesis results investigated a generic classifier using Genetic Programming to classify multiple anomaly phenomena. This work can be bridged together with the unit event grit classification work.

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Goodall, Clifton. "A study of the throughfeed centreless grinding process with particular reference to the size accuracy." Thesis, Liverpool John Moores University, 1990. http://researchonline.ljmu.ac.uk/4985/.

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Diao, Jie. "Development of Techniques to Quantify Chemical and Mechanical Modifications of Polymer Surfaces: Application to Chemical Mechanical Polishing." Diss., Available online, Georgia Institute of Technology, 2004, 2004. http://etd.gatech.edu/theses/available/etd-11222004-001703/.

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Thesis (Ph. D.)--Chemical Engineering, Georgia Institute of Technology, 2006.
Samuels, Robert J., Committee Member ; Henderson, Clifford L., Committee Member ; Danyluk, Steven, Committee Member ; Hess, Dennis W., Committee Chair ; Bottomley, Lawrence A., Committee Member ; Morris, Jeffrey F., Committee Co-Chair. Vita. Includes bibliographical references.

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Nisal, Tejas V. "Monitoring of Surface Grinding process using Acoustic Emission (AE) with emphasis on Cutting Fluid selection." University of Toledo / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1404341563.

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Дисертації з теми "Mechanical grinding"

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