Progress in abrasive and grinding technology

Tai ngay!!! Ban co the xoa dong chu nay!!! Progress in Abrasive and Grinding Technology Progress in Abrasive and Grinding Technology Special topic volume with invited papers only Edited by Xipeng Xu TRANS TECH PUBLICATIONS LTD Switzerland • UK • USA Copyright  2009 Trans Tech Publications Ltd, Switzerland All rights reserved No part of the contents of this publication may be reproduced or transmitted in any form or by any means without the written permission of the publisher Trans Tech Publications Ltd Laubisrutistr 24 CH-8712 Stafa-Zurich Switzerland http://www.ttp.net Volume 404 of Key Engineering Materials ISSN 1013-9826 Full text available online at http://www.scientific.net Distributed worldwide by and in the Americas by Trans Tech Publications Ltd Laubisrutistr 24 CH-8712 Stafa-Zurich Switzerland Trans Tech Publications Inc PO Box 699, May Street Enfield, NH 03748 USA Fax: +41 (44) 922 10 33 e-mail: sales@ttp.net Phone: +1 (603) 632-7377 Fax: +1 (603) 632-5611 e-mail: sales-usa@ttp.net Preface Grinding and abrasive processing of materials are the machining processes that use bonded or loose abrasives to remove workpiece materials Due to the well-known advantages of grinding and abrasive processes, advances in abrasive and grinding technology are of importance to enhance both productivity and part quality In order to introduce the progresses in this field, the vice president of Trans Tech Publications, Thomas Wohlbier, invited me to edit this special volume last year I have invited 21 contributions from different countries and regions in an attempt to gather together the achievements of different researchers into a single publication The 21 invited papers, review or research, are from Australia, China, Germany, Japan, Singapore, Taiwan (China), UK, and USA The abrasive processes addressed in the volume involve not only grinding and polishing, but also wire sawing and abrasive waterjet machining The topics include either fundamental aspects or novel techniques It is therefore the hope of the editor that this volume will be valuable to production and research engineers, research students and academics in the area At the completion of this volume, I am grateful to all the contributors for the enthusiasm with which they wrote about their topics Thanks are also given to Mr Guoqin Huang at HuaQiao University for his secretarial and editing work; and Trans Tech Publications for publishing the volume Xipeng Xu Ph.D Professor in Manufacturing Engineering HuaQiao University Quanzhou, Fujian 362021, China Tel.: +86-595-22693598; fax: +86-595-22692667 E-mail address: xpxu@hqu.edu.cn Table of Contents Preface Development in the Dressing of Super Abrasive Grinding Wheels B Denkena, L de Leon, B Wang and D Hahmann High Speed Grinding of Advanced Ceramics: A Review H Huang Experimental Investigations on Material Removal Rate and Surface Roughness in Lapping of Substrate Wafers: A Literature Review W.L Cong, P.F Zhang and Z.J Pei A Focused Review on Enhancing the Abrasive Waterjet Cutting Performance by Using Controlled Nozzle Oscillation J Wang A Review of Electrolytic In-Process Dressing (ELID) Grinding R Mustafizur, A Senthil Kumar and I Biswas On the Coherent Length of Fluid Nozzles in Grinding M.N Morgan and V Baines-Jones Surface Characteristics of Efficient-Ground Alumina and Zirconia Ceramics for Dental Applications H Kasuga, H Ohmori, Y Watanabe and T Mishima Optimization of Cutting-Edge Truncation in Ductile-Mode Grinding of Optical Glass J Tamaki and A Kubo On the Polishing Techniques of Diamond and Diamond Composites Y Chen and L.C Zhang Super Polishing Behaviour Investigation of Stainless Steel Optical Lens Moulding Inserts K Liu, S.T Ng, K.C Shaw and G.C Lim Corrective Abrasive Polishing Processes for Freeform Surface X Chen Applications of Contact Length Models in Grinding Processes H.S Qi, B Mills and X.P Xu Polishing Performance of Electro-Rheological Fluid of Polymerized Liquid Crystal Contained Abrasive Grit T Tanaka Study on Tribo-Fabrication in Polishing by Nano Diamond Colloid W.M Lin, T Kato, H Ohmori and E Osawa Efficient Super-Smooth Finishing Characteristics of SiC Materials through the Use of FineGrinding H Kasuga, H Ohmori, W.M Lin, Y Watanabe, T Mishima and T.K Doi Polishing of Ultra Smooth Surface with Nanoparticle Colloid Jet F.H Zhang, X.Z Song, Y Zhang and D.R Luan An Experimental Study on High Speed Grinding of Granite with a Segmented Diamond Wheel X.P Xu, X.W Zhu and Y Li Thinning Silicon Wafer with Polycrystalline Diamond Tools P.L Tso and C.H Chen Mechanisms of Al/SiC Composite Machining with Diamond Whiskers G.F Zhang, B Zhang and Z.H Deng Effect of Slurry and Nozzle on Hole Machining of Glass by Micro Abrasive Suspension Jets C.Y Wang, P.X Yang, J.M Fan and Y.X Song Experimental Investigation of Temperatures in Diamond Wire Sawing Granite H Huang, N Guo and X.P Xu 11 23 33 45 61 69 77 85 97 103 113 123 131 137 143 149 157 165 177 185 Key Engineering Materials Vol 404 (2009) pp 1-10 © (2009) Trans Tech Publications, Switzerland doi:10.4028/www.scientific.net/KEM.404.1 Development in the Dressing of Super Abrasive Grinding Wheels B Denkena1,a, L.D Leon1,b, B Wang1,c and D Hahmann1,d Leibniz Universität Hannover, Institute of Production Engineering and Machine Tools, An der Universität 2, D-30823, Germany a denkena@ifw.uni-hannover.de; bleon@ifw.uni-hannover.de; cwang@ifw.uni-hannover.de; d hahmann@ifw.uni-hannover.de Keywords: Electro contact discharge dressing, Profile dressing, Microprofiles, Super abrasives Abstract Harder workpiece materials and increased efficiency requirements for grinding processes make the use of super abrasive grinding wheels indispensable This paper presents newly developed processes for the dressing of super abrasive grinding wheels The different bond systems of grinding wheels require distinct dressing process In this paper, dressing processes for metal and vitrified bonded grinding wheels are investigated It introduces the method of electro contact discharge dressing for the conditioning of metal-bonded, fine-grained multilayer grinding wheels A description of the essential correlation between dressing parameters and the material removal rate of the bond material is presented The considered parameters are the dressing voltage, the limitation of the dressing current and the feed as well as the infeed of the electrode For the grinding of functional microgroove structures, multiroof profiles with microscopic tip geometries are dressed onto the grinding wheel For this, a profile roller in combination with a special shifting strategy is applied on finegrained vitrified bonded grinding wheels Introduction High performance components with high hardness and wear resistance are applied with increasing frequency in order to enhance the efficiency of technical systems Furthermore, miniaturized products and microstructured functional surfaces entail new challenges for machining processes Grinding processes with super abrasive CBN and diamond grinding wheels can be used for the economical machining of such components and microgeometries Depending on the bond system of the grinding wheel, different dressing processes should be used [1, 2] To assure small form and dimensional tolerances over an adequate number of workpieces, the grinding wheels have to be regularly redressed In the following, electro contact discharge dressing for metal bonded grinding wheels and a novel dressing strategy using special shift kinematics for vitrified bonded grinding wheels are described The focus of these dressing processes is the profiling of grinding wheels Electro Contact Discharge Dressing The effects of continuous wear on process stability as well as on shape and dimension accuracies of a component are more significant for fine-grained grinding tools used for micro-machining than they are for “conventional” precision grinding In order to counterbalance those influences, wear-resistant grinding tools and procedures for the regeneration of the tool profile are necessary Due to their high wear-resistance and the resulting profile retention, multilayered, metallically bonded diamond grinding wheels are more suitable for micromachining than vitrified or resin bonded tools The main problem is the dressing of those metallically bonded tools Electro contact discharge dressing is a promising method to cope with this challenge It has so far only been used for sharpening, but not for the dressing of tools [3~5] In the following, the effects of the process variables on the contact erosive removal of the bond material are described It is determined under which conditions a continuous removal of the bond material and thus a durable dressing effect can be achieved Emphasis is put on the significant variables such as the dressing voltage Ud0, the limitation of the dressing current Id0 and the chip Progress in Abrasive and Grinding Technology volume over the dressing time Qd These parameters all vary depending on the strategy chosen for the electrode infeed frd and the electrode feed vfd As start-up phase for electro contact discharge dressing, the split stroke travel with idle stroke is chosen Thus the effects of the variables can be determined (Fig.1) The aim of the dressing strategy is to attain an even distribution of graphite particles over the thickness of the grinding wheel The electrode is aligned radially next to the dressing wheel (1) The electrode is then passed diagonally into the grinding layer (vfd, lfda1) until the electrode and the grinding wheel overlap axially (2) In the second partial stroke, there is no further radial infeed (vfda, lfda2) This is to increase the influence on the grinding layer during the electrode withdrawal and to guarantee an even electrode profile (3) The axial return stroke (vfda) to the initial position is also carried out without radial infeed (1) This is to provide a further smoothing of the profile The current Id and the voltage Ud, both recorded during the process, show the effect of the different partial strokes on the process activity The highest process activity occurs when the diagonal feed of the electrode is carried out and when the electrode and the grinding wheel overlap In the following axial progress of the electrode, the activity slowly decreases and comes to a standstill when there is no more contact between the two interacting parts The following idle stroke leads to low process activity Fig Start-up phase of electro contact discharge dressing with idle stroke The effects of the variables on the process are described by the specific material removal rate Q’ds and by the quality factor Gd The quality factor Gd is the ratio of the bond material volume removed from the dressing wheel and the machined volume of the electrode The experiments were carried out in distilled water, which has proved to be a suitable medium in preexaminations The dressing voltage Ud0 is the off-load voltage, while the dressing current Id0 is the maximal current in a short circuit which can be set at the power supply unit They can be adjusted reproducibly The actual voltage Ud and the current Id vary throughout the process At first, the dressing voltage Ud0 is varied, while the current Id0 is constant (Fig 2, left) In order to attain a dressing effect, the voltage has to exceed a critical value which causes a maximal grain protrusion and a continuous removal of bond material Under given boundary conditions, there is no measurable removal of bonding material at Ud0 = 15 V When Ud0 is further increased, the volume flow rate Q’ds increases At a voltage of Ud0 = 30 V, the maximal attainable volume flow rate Q’ds is Key Engineering Materials Vol 404 reached When the off-load voltage increases further, there is no further rise in Q’ds, which means that the run of the curve has approached a critical value In the following, a possible explanation for Q’ds development against the voltage is presented The sizes of the graphite particles cut off from the electrode show a distinct distribution At low voltages, only few particles are large enough to enable discharges When the voltage increases, the number of suitable particles and thus the probability of discharge increase An analogy investigation, carried out under the same electric and geometric conditions as in the real process, showed that at about 35 V, discharges even occur without any graphite particles implied This shows that the maximal probability of discharge is reached The limiting factor is that there can only be one discharge at a time When a current limit Id0 is determined in advance, this limit directly influences the intensity of the electro contact discharge process (Fig 2, right) The electrode current in the spark gap occurs at the electrode voltage Ud as a consequence of the existing resistance according to Ohm’s law It is the sum of the local single currents which cause the removal of the bond material Low current limits Id0 lead to a low volume flow rate Q’ds In analogy to the voltage Ud0, the maximal volume flow rate of about Q’ds = 0.13 mm3/mm s is attained at Id0 = A When Id0 further increases, there is no more rise in the volume flow rate at the grinding wheel This can be explained by the energy released at each discharge under the assumption of a constant discharge duration The energy released at a discharge and thus the temperature in the metal bond increase with a rise in the current At a certain energy level, the metal bond starts to melt locally The maximal volume of bond which can be molten is limited by the specific boiling temperature and the specific thermal conductivity The temperature of the molten material cannot exceed the boiling temperature Thermal conductivity limits the volume of material which reaches the melting temperature due to heat dispersion, assuming a constant discharge duration The duration will be determined from the experimental data Fig Specific material removal rate during electro contact discharge dressing In Fig 3, the quality factor Gd is shown against the dressing voltage Ud0 and the current limit Id0 Up to Ud0 = 30 V, the quality factor rises with about Gd = 4.5 at the maximal volume flow rate Q’ds When Ud0 increases further, the quality factor stays on a constant level The quality factor shows a similar behavior by a variation of Id0 The maximal quality factor is reached at a current level of about Id0 = A The quality factor also stays on a constant level when Id0 increases further The development of the quality factor in both diagrams can be explained by the constant specific material removal rate at the electrode, which is itself due to constant infeed and feed throughout the investigation Thus the quality factor corresponds to the specific material removal rate Progress in Abrasive and Grinding Technology Fig Quality factor in electro contact discharge dressing Fig Specific material removal rate in electro contact discharge dressing Besides by the electric variables of electro contact discharge dressing, the process is also influenced by the radial electrode infeed frd and by the feed vfd In the investigations, the feed is identical for all single strokes (see Fig 1) The feed and infeed develop against the volume flow rate Q’ds in the same way as the electric variables described above When frd increases, initially the volume flow rate Q’ds rises The maximal volume flow rate of about Q’ds = 0.1 mm3/mm s is reached with an infeed of about frd = 10 µm A further increase in frd causes no further rise in the volume flow rate Q’ds A variation of the feed of the electrode vfd leads to very similar results In this case the maximal volume flow rate is achieved at vfd = 20 mm/min A possible explanation for the development of both curves is the mean particle size of the graphite particles that are cut off from the electrode The mean particle size rises both when the feed or the infeed increase This is due to the increase in the equivalent mean chip thickness The probability of discharge increases with the particle size until the maximal probability of discharge is reached The limiting factor is that there can only be one discharge at a time Key Engineering Materials Vol 404 181 Table The influence of the abrasives and various polyacrylamide to MASJ processing Boron carbide Abrasives White Garnet corundum Polyacrylamide Brown corundum PAM PAMA HPAM Front view Side view Diameter [mm] Depth [mm] Material removal [mg] 0.61 2.6 3.9 0.71 2.2 3.6 0.82 2.1 3.5 0.84 1.9 2.9 0.59 0.63 0.61 1.35 0.61 1.1 1.9 1.1 1.7 P=10MPa; t=25s; Ds=2mm; α=90°; P= 10MPa; t= 35s; Ds=2 mm; α= 90°; ρ= 158.3 g/L ; 5106molecular weight Proceeding conations 0.6% 510 molecular weight PAM, 4% SBN, full polyacrylamide; ρ= 166.2g/L; white length nozzle of diameter: 0.12 mm, corundum; 4% SBN, full length nozzle of diameter: 0.12 mm (1) Boron carbide Boron carbide has the highest hardness, best suspension and dispersing performance among the four abrasives The smooth hole is the deepest, the diameter is the smallest in the tests In Table 2, zone A of processing stage I is larger than in Fig.2 due to lower working pressure Boron carbide facilitates to make deeper hole However, the price of boron carbide is much higher than the other three, so it doesn’t be used for more drilling process in this study (2) Garnet Garnet abrasives can be also used to make slurry with longer and stable machining than those made of brown corundum and white corundum But garnet abrasive is mostly spherical, as observed under microscope, the hole margins are filled with cracks, and the side view of drilled hole shows irregular shapes, see Table (3) White corundum The white corundum abrasive is hexagonal structure, with many sharp cutting edges Adding with polyacrylamide, the suspensibility of the white corundum abrasive is fine The margin of the hole drilled maintains good shape in general The front view of the hole in Table shows the defect caused by the broken needle in test The side view shows better profile for obtaining a through hole Referring to the cheaper price and better eroding performance, the white corundum is the best abrasives used for MASJ drilling (4) Brown corundum Cheap brown corundum shows better hole shape, but using brown corundum the jet nozzle is easy to be blocked up and damaged in the test, Influence of the Polyacrylamide The MASJ slurry made of PAM is more viscous and suspended better than that made of others Using PAM can drill the deepest and the smallest diameter holes with the best quality and the highest material removal than using PAMA, HPAM, see Table Twelve million molecular weight PAM cause serious nozzle wear and blocked up because serious abrasives agglomerating Smaller molecular weight PAM can form shorter polymer chain and not obvious bridging, so that it can suspend abrasives and inhabit agglomerating of them better Five million molecular weight PAM is better than twelve million molecular weight PAM for making MASJ slurry, and is used in the test Influence of the Concentration of PAM In Fig.5, the RSH of slurries for different concentration of PAM decreases gradually with processing time When the concentration of PAM increases to 0.6%, the precipitating volume has reached to a constant value and then keeping a stable suspended state Drilling by the slurries of different concentration of PAM, the shape of the hole, depth of drilling and the diameter are shown in Fig.6 The depth and the material removal of the hole increase 182 Progress in Abrasive and Grinding Technology Relative Sedimentation Height RSH gradually with the growing of concentration of PAM in the test It can be found that 0.6% PAM obtains the better hole quality and the front view of hole is broken seriously as using 0.9% PAM From the results discussed in above, it can be found that the diameter of the drilled holes is more than five times that of nozzle To decrease the diameter of drilled hole, using much smaller nozzles will increase not only the difficulties to manufacture nozzle and slurry, but also the possibility to block up the abrasives inner the nozzle The mask should be use to decrease the unnecessary abrasive eroding of the MASJ stream in order to get smaller eroding zone, and smaller hole or cutting finer structure The better MASJ drilling quality can be achieved only by means of optimal processing parameters and processing control, which will be discussed in further works 1.0 0.8 15min 30min 45min 60min 75min 0.6 0.4 0.2 0.3 0.6 The concentration of PAM (%) 0.9 Fig Effect of the concentration of PAM on RSH (ρ=300 g/L; 700# white corundum; 4% SBN) 1.6 Dimension of the hole (mm) Material removal (mg) 2.4 1.8 1.2 0.6 Diameter of the hole Depth of the hole 1.2 0.8 0.4 (a) 0.3 0.6 Concentration of PAM (%) 0.9 (b) 0.3 0.6 Concentration of PAM (%) 0.9 Fig.6 Effect of the concentration of PAM (a) material removal, (b) size of holes (P=10 MPa; t=25 s; α= 90°; Ds=0.12 mm; abrasive: 700# white corundum; ρ=166.2 g/L; 4% SBN, full length nozzle of diameter: 0.12 mm) Conclusions 1) The MASJ process of glass can be decribed as four stages The surface brittle removal forms bowl-shaped opening zone in stage I, stable removal of the abrasive jet forms vertical hole in stage II, second erosion of abrasives forms a convex shape zone in stage III and a conical shaped hole forms finally in stage IV Four processing stages depend on the processing conditions, including the vibration and toughness of nozzle 2) The longer the length of nozzle cylindercal duct is, the better the quality of the drilled holes will be achieved 3) The categories of the abrasive influence the drilling process, and the white corundum abrasive can be used in MASJ for its better suspensibility and eroding performance 4) Five million molecular weight PAM with concentration of 0.6% is the optimal subspension for obtaining the deep and good quality hole Key Engineering Materials Vol 404 183 Acknowledgement The authors wish to acknowledge the National Natural Science Foundation of China (Grant No 504750450) References [1] D.S Miller: Development of Micro-Abrasive Water-Jets, BHR 15th International Conference on Jetting Technology, (2001), pp.35-45 [2] D.S Miller: J Mater Process Technol., Vol 149, (2004), pp.7-42 [3] M Hashish: Abrasive Water Jet Cutting of Microelectronic Components 2005 WJTA American Waterjet Conference, Houston, Texas, (2005), Vol.1 A-1 [4] D.S Miller: Developments in Abrasive Waterjets for Micromachining, BHR 16th International Conference on Jetting Technology, (2003) [5] R.G Hou, C.Z Huang and J Wang: Key Eng Mater, Vol 315 (2006), pp 150-153 [6] C.Y Wang, M.D Chen, P.X Yang and J.M Fan: Key Eng Mater., Vols 389-390 (2009), pp 381-386 [7] H Wensink, M.C Elwenspoek: Sensors and Actuators A, Vols 102 (2002), pp 157-164 [8] J.M Fan, C.Y Wang, J Wang and G.S Luo: Key Eng Mater, Vols 359-360 (2008), pp.404-408 Key Engineering Materials Vol 404 (2009) pp 185-191 © (2009) Trans Tech Publications, Switzerland doi:10.4028/www.scientific.net/KEM.404.185 Experimental Investigation of Temperatures in Diamond Wire Sawing Granite H Huang1,a, L Guo1 and X.P Xu1,b Province Key Research Lab for Stone Machining, Huaqiao University, Quanzhou, Fujian Province 362021, China a huangh@hqu.edu.cn; xpxu@hqu.edu.cn Keywords: Diamond wire sawing, Background temperature, Granite Abstract The background temperatures in the sawing of granite with a diamond wire were measured by foil thermocouple The influences of the measuring position in the cutting zone, cutting speed, feed rate and coolant on the temperature were investigated The results indicated that the background temperature would be stable after a short-term rise It was shown that the background temperature increased with cutting speed, but there was no obvious relationship between the background temperature and feed rate The maximum background temperature appeared at the front part of the cutting zone at a lower feed rate With an increase of feed rate, the background temperature at the middle of the cutting zone was the highest The coolant had an obvious influence on the maximum background temperature Introduction Since the first diamond wire was introduced successfully in Italy APUAN marble quarrying in 1978, diamond wire sawing has been widely used in many applications in stone quarrying, complex stone shapes sawing, civil engineering and metal cutting, etc.[1-2] Diamond wire sawing was regarded as one of the most key technologies lighting up the future of diamond tools in stone processing due to their environmental benefits, higher extraction rates, greater yield and ultimately cost competitiveness [3] The diamond wire is actually a steel wire on which many beads bonded with diamond abrasive are mounted at a regular interval with spacing material placed between the beads, as shown in Fig The beads act on the cutting role in machining Steel spring, molded plastic or rubber is used as a separator to fix and insulate the beads The flexible steel wire, like a "spine", threads all the beads The diamond wire is rotated with driving wheel movement The tension and rotation force required for cutting are provided by the driving wheel There are three machining modes applied for wire sawing, namely, quarry machining, stationary machining and multi-wire machining [1] Notwithstanding that they are used in completely different application areas, there are still some common machining features in the three methods which are different from those of circular sawing and gang sawing Long cutting arc For stationary wire sawing, the contact length of the diamond wire is several meters, and dozens of meters for quarry wire sawing, which is hundreds or thousands times longer than that of the traditional circular sawing, as shown in Fig.1 Low intermittent ratio The beads are spaced at 35-40 per meter for ordinary diamond wire and each bead is 6.5 mm in length Thus, the cutting length is less than 0.26 meter per meter The intermittent ratio of wire sawing is less than 26% which is much lower than that of circular sawing and traditional intermittent grinding Flexible cutting mode Compared with circular and gang sawing, diamond wire sawing belongs to a flexible mode The diamond wire could be bent in cutting process due to the elasticity of twist steel, as shown in Fig The degree of curvature closely relates to cutting feed rate The flexible cutting mode allows the diamond bead to give way when the cutting force is too high, which holds back the violent crash between the diamond grit and workpiece 186 Progress in Abrasive and Grinding Technology Matrix + Diamond grits Spacer Steel ring Steel wire Diamond bead Vs workpiece Fig Illustration of the diamond wire sawing Due to the long cutting arc and low intermittent ratio, the wear of the diamond wire is more severe than that of the circular sawing In the past several decades, some researches have been focused on the wear of diamond beads and how to improve the bonding between the matrix and diamond grits [4-5] But the improvement of diamond wire performance is limited due to few researches on the wire sawing mechanism The sawing force and sawing temperature are the most important factors for the diamond wear [6] Therefore, the present research was undertaken to investigate the temperature on contact arc of the diamond wire and workpiece, which would provide a better understanding of the diamond wire wear Experimental The experimental setup is schematically illustrated in Fig.2 Granite sawing experiment is conducted on a CNC diamond wire stationary machine which is smaller than the commercial machine The diamond wire used here is 5.5m long and contains 37 beads per mete Metal bonded abrasive bead contains 40/50 US mesh diamond with a concentration of 40 The beads are mm in diameter and 6.5 mm in length with each being separated by mould plastic The tensile force of wire sawing is 1500 N The workpiece with the dimension of 600×250×250 mm is typical natural granite (G614) which belongs to the middling hard granite consisting of approximately 25% quartz, 5% orthoclase, 60% plagioclase and 10% for others Water is used as the coolant Wire speed Vs: 13.3~25.1 m/s; Feed speed Vf : 0.5~2 m/h; Vs Vf Diamond wire Driving wheel Measuring point Tension PC Computer Driven wheel Thermocouple Workpiece A/D board Mica Ice point Fig Illustration of the setup for temperature measurement Key Engineering Materials Vol 404 187 Sawing temperature in the cutting zone was measured on the workpiece surface with a grindable foil thermocouple which consisted of a pair of rectangular K chromel-alumel with 0.1 mm in thickness and 1.6 mm in width, which was insulated by mica with 0.03 mm thickness [7].Schematic graph of sensor assembly is illustrated in Fig In order to obtain more favorable temperature signals, two workpiece surfaces were ground and polished in order for a compact contact, as shown in Fig.3 The cold junction was immersed in ice water The output voltage signals from the thermocouple, sampled at 10K Hz, were recorded by a PC computer through an A/D converter Then the voltage signals were switched to temperature signals and analyzed by Origin Polished surface Workpiece Chromel wire Workpiece Mica sheets Constantan wire Fig Illustration of the arrangement of electrodes and the split workpieces In order to obtain temperature signals of different positions along the cutting zone, four measurement points were adopted which were 100 mm, 200 mm, 300 mm and 500 mm along the wire entrance into workpiece, as shown in Fig The wire speed and feed rate varied from 13.3 to 25.1 m/s and 0.5 to m/h respectively Results and Discussion An example of the temperature signals recorded during a single sawing pass is shown in Fig Generally speaking, the temperature responses recorded by the foil thermocouple consist of two components, namely, a “background” temperature and a “spike” temperature The background temperature, associated with continuous heating, has been found to be associated with thermal damage [8] For the temperature response of wire saw, it’s difficult to find background temperature which is covered by the spike temperature In order to obtain the background temperature, the temperature signal is low-pass filtered with 1HZ as shown in Fig.5 It’s found the background temperature is about 5℃ which is far lower than that of the traditional circular sawing [9] For the traditional grinding, a quasi-steady state moving heat source model was used to calculate the temperature distribution within the workpiece This model assumes two dimensional heat transfers in the x-z plane with either a uniform (rectangular) heat source distribution on the workpiece surface along the grinding zone of the length, as shown in Fig 6a or a triangular heat source distribution The moving direction of heat source is the same as that of feed rate An intermittent moving heat source model was established according to the movement of diamond wire sawing, as shown in Fig 6b Different from the traditional model, the moving direction of heat source is perpendicular to that of feed rate So the shape of temperature curve of diamond wire sawing is different from that of circular sawing, as shown in Fig [9] For the wire sawing, the measuring points were always kept on the surface between the workpiece and wire tools, which showed became the temperature in contact arc The background temperature in the cutting zone becomes stable after a short heating-up, as shown in Fig 188 Progress in Abrasive and Grinding Technology Vs =21.3 m/s Vf =1 m/h l = 200 mm Fig Temperature/time variation at a point on the workpiece surface Vs =21.3 m/s Vf =1 m/h l = 200 mm Fig The curve of filter temperature q q Vw Vs Vf (a) The movement of heat flux for the circular sawing (b).The movement of heat flux for the wire sawing Fig The movement of heat flux for the different sawing methods The Influence of Cutting Rate The change of background temperature at the measuring point of 200mm and 500mm with cutting rate of wire saw is shown in Fig.7 The number of beads acting on workpiece per unit of time increases with the increase of cutting speed which results in the increase in power consumption So an obvious rise on the temperature with the increase of cutting rate, as shown in Fig Key Engineering Materials Vol 404 189 l = 500 mm l = 200 mm Background temperature T Vf = 1m/h 12 14 16 18 20 22 24 26 Wheel rotating speed Vs (m/s) Fig Background temperature versus the wheel rotating speed The Influence of Feed Rate The change of background temperature at the different measuring positions versus the feed rate is shown in Fig Compared with the monotony increase trend for the background temperature with the increase of feed rate in the circular sawing, no obvious regularity can be found from Fig The value of the background temperature varies widely at the different measuring positions when the feed rate is 1.5 m/h However, the average background temperature is higher at this feed rate than any other feed rate When the feed rate is 1.0 m/h, there is no obvious change of the temperature at the different measuring positions But the average background temperature is the lowest It’s held that this irregularity may be caused by different vibrations under different feed rates, which will be discussed elsewhere 14 100 mm 200 mm 300 mm 500 mm Background temperature T 12 Vs = 17.85 m/s 10 1.0 1.5 2.0 Feed speed Vf (m/h) Fig Background temperature versus the feed speed The Influence of Measuring Position Fig.9 shows the change of background temperature in accordance with measuring positions It’s found that the front part temperature is higher than the rear part temperature in sawing arc in case of a low feed rate With the increase of feed rate, the middle part temperature obviously increases No obvious temperature variation has been found at the rear part of the cutting arc The feed rates have obvious effect upon the temperature at the different measuring points due to the bend for diamond wire in cutting process When the feed rate is 1.5m/h, the background temperature in cutting arc mounts to the highest 190 Progress in Abrasive and Grinding Technology 14 Vf = 0.5 m/h Vs = 17.85 m/s Vf = 1.0 m/h 12 Background temperature T Vf = 1.5 m/h Vf = 2.0 m/h 10 0 100 200 300 400 500 600 Measurement point l (mm) Fig Background temperature in the different measurement distance The Influence of Coolant The influence of coolant on the background temperature is shown in Fig.10 It’s found that there is an obvious rise in the background temperature of no coolant The value of background temperature without coolant is times greater than the case with coolant Obviously, the low intermittent ratio provides the plenty coolant to reduce the background temperature in the sawing arc 50 Background temperature T 40 Vs = 17.8 m/s Vf = m/h l = 500 mm 30 20 10 With coolant Without coolant Sawing with and without coolant Fig 10 Background temperature with and without coolant Conclusion The background temperature would be stable after a short-term rise The background temperature increased with cutting speed, but no obvious relationship with feed rate The maximum background temperature appeared at the front part of the cutting zone under low feed rate With the increase of feed rate, the background temperature at the middle of the cutting zone instead of the front part turned to be the highest Coolant had an obvious influence to reduce the background temperature Acknowledgment The research was financially supported by Grant No E0810020 from the Natural Science Foundation of Fujian Province in China and by Projects from the Department of Science and Technology in Fujian Province, China (2006F1007 and 2007H2003) Key Engineering Materials Vol 404 191 References [1] D.N Wright and J.A Engels: The Environmental and Cost Benefits of Using Diamond Wire for Quarrying and Processing of Natural Stone, IDR, (2003) No 4, pp 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Technology: Theory and Application of Machining with Abrasive, John Wiley & Sons, New York Reprinted by SME, 1989 [9] X.P Xu, S Malkin: Comparison of Methods to Measure Grinding Temperature, ASME: Journal of Manufacturing Science and Engineering, Vol 123 (2001), pp.191-195 Keywords Index 4H-SiC 137 F A Abrasive Processing Abrasive Water Jet Aluminum-Silicon Carbide Composites 103 33 165 185 69 C Ceramic Coherent Length Colloid Composites Contact Length Coolant Delivery Coolant Supply Copper (Cu) Corrective Finishing Crack Criterion for Model Simplification Cutting Edge Truncation 11 103 131 G B Background Temperature Brittle Material Force Freeform Surface Friction Coefficient Glass Granite Grinding Ground Surface Roughness 177 149, 185 61, 113, 149 77 H 11 61 143 85 113 61 11 123 103 157 113 77 Hard Material High Quality Surface High Speed Grinding 69 137 11 I In-Feed Grinding 137 L Lapping Laser Cutting 23 165 M D Damaged Layer Dental Ceramic Diamond Diamond Whisker Diamond Wire Sawing Drilling Ductile Mode Grinding 157 69 85, 149 165 185 177 77 E Electro-Contact Discharge Dressing Electro-Rheological Fluid Electrolytic Dressing ELID (ELectrolytic In-Process Dressing) Grinding Machining Machining Performance Material Removal Material Removal Mechanism Material Removal Rate (MRR) Maximum Grain Depth of Cut Micro Abrasive Suspension Jet Microprofile Monte-Carlo Simulation Moulding Insert 33 33 131 165 23 77 177 77 97 N 123 45 45, 69, 137 Nano Diamond Colloid Nanoparticles Nozzle Nozzle Oscillation 131 143 61 33 194 Progress in Abrasive and Grinding Technology O One-Sided Pattern Electrodes Optical Lens 123 97 P Polishing Polycrystalline Diamond (PCD) Polymerized Liquid Crystal Profile Dressing 85, 97, 103, 123, 131, 143 85, 157 123 Q Quartz Glass 77 R Review 45 S Sapphire Silicon Sintered SiC Speed Stainless Steel Substrate Wafer Subsurface Super Abrasive Surface Characteristic Surface Properties Surface Roughness (SR) 23 23 137 149 97 23 11 69 137 23, 123, 131 T Temperature Tribo-Fabrication 11 131 U Ultra Smooth Surface 143 W Wafer Thinning Waterjet Wear 157 177 131 Authors Index Mustafizur, R B Baines-Jones, V Biswas, I 61 45 45 N Ng, S.T 97 C Chen, C.H Chen, X Chen, Y Cong, W.L 157 103 85 23 O Ohmori, H Osawa, E 69, 131, 137 131 P D de Leon, L Deng, Z.H Denkena, B Doi, T.K Pei, Z.J 165 137 177 G Guo, N Q Qi, H.S 113 S F Fan, J.M 23 Senthil Kumar, A Shaw, K.C Song, X.Z Song, Y.X 45 97 143 177 185 T H Hahmann, D Huang, H 11, 185 77 123 157 W K Kasuga, H Kato, T Kubo, A Tamaki, J Tanaka, T Tso, P.L 69, 137 131 77 Wang, B Wang, C.Y Wang, J Watanabe, Y 177 33 69, 137 L Li, Y Lim, G.C Lin, W.M Liu, K Luan, D.R 149 97 131, 137 97 143 M Mills, B Mishima, T Morgan, M.N X Xu, X.P 113, 149, 185 Y Yang, P.X 177 Z 113 69, 137 61 Zhang, B Zhang, F.H 165 143 196 Zhang, G.F Zhang, L.C Zhang, P.F Zhang, Y Zhu, X.W Progress in Abrasive and Grinding Technology 165 85 23 143 149