Sawing of Granite with Side-Slotted Diamond Segments

2006 ◽  
Vol 315-316 ◽  
pp. 103-107
Author(s):  
Yi Qing Yu ◽  
Y.F. Zhang ◽  
Yuan Li ◽  
Xi Peng Xu

The present study was undertaken to examine the feasibility of circular sawing of granite with a newly shaped diamond saw blade. Three slots were formed on each side of each segment of the saw blade. Side-slotted segments and traditional segments were compared under same operating parameters. Measurements were made of the horizontal and vertical force components and the consumed power in order to obtain the tangential and normal force components. The surfaces of worn blade segments were examined by a scanning electron microscope. The consumed powers, normal and tangential force components for the side-slotted segments were found to be lower than those of the traditional segments. The position of resultant forces for the side-slotted segments is a little further away from the bottom of the cutting zone than the traditional segments. SEM observations indicated that the wear of the side-slotted segments was similar to sawing with traditional segments.

2000 ◽  
Vol 123 (1) ◽  
pp. 13-22 ◽  
Author(s):  
Xipeng Xu ◽  
Yuan Li ◽  
Stephen Malkin

An investigation is reported of the forces and energy in circular sawing and grinding of gray granite. Measurements were made of the forces and power over a wide range of sawing and grinding conditions. Calculated tangential force components were found to be much different than the measured horizontal force components for sawing, but the two forces were almost identical for grinding. The location of the resultant force was proportionally further away from the bottom of the cutting zone with longer contact lengths. For sawing, the normal force per grain was nearly proportional to the calculated undeformed chip thickness. The G-ratios at different sawing rates reached a maximum value at the same intermediate undeformed chip thickness, which was attributed to a transition in the diamond wear mechanism from attrition to fracture at a critical normal force per grain. SEM observations indicated material removal mainly by brittle fracture, with some evidence of ductile plowing especially for grinding and to a lesser extent for sawing. The corresponding fracture energy was estimated to constitute a negligible portion of the total energy expenditure. About 30 percent of the sawing energy might be due to the interaction of the swarf with the applied fluid and bond matrix. Most of the energy for sawing and grinding is attributed to ductile plowing. Analogous to recent studies on grinding of ceramics and glass, the power per unit width was found to increase linearly with the generation of plowed surface area per unit width.


2011 ◽  
Vol 487 ◽  
pp. 357-360
Author(s):  
Cong Fu Fang ◽  
Xi Peng Xu

The effects of the machining parameters on the relative position of the resultant force were analyzed in circular sawing of granite with a diamond segmented blade. The horizontal and vertical force components and the power were measured. Calculated tangential and normal force components were subsequently used to calculate the relative position of resultant force besides the horizontal and vertical force components. It was found that the value of the relative position of resultant force in down sawing is less than that in up sawing. The shift of sawing swarf has heavy influence on the relative position of resultant force.


2006 ◽  
Vol 315-316 ◽  
pp. 185-189 ◽  
Author(s):  
Hui Huang ◽  
G.Q. Zhang ◽  
Y.J. Zhan ◽  
Xi Peng Xu

An experimental study was carried out to investigate the process in surface grinding of two kinds of typical granite with a brazed diamond wheel. The horizontal and vertical forces were measured to obtain the data for the tangential and vertical force components as well as specific energy. Micrograph observations on tool surface and granite surface were coupled to check the prevailing mechanisms for material removal. Although the red granite is more difficult to machine than the black granite, according to factory records, the normal and tangential force components and specific energy for red granite were lower than that for black one, which might be attributed to the high height protrusion of brazed tool and the more ductile flow occurred in the grinding arc of black granite compared to the red one.


Robotica ◽  
2004 ◽  
Vol 22 (2) ◽  
pp. 213-221 ◽  
Author(s):  
Masahiro Ohka ◽  
Yasunaga Mitsuya ◽  
Yasuaki Matsunaga ◽  
Shuichi Takeuchi

This paper describes precision enhancement of an optical three-axis tactile sensor capable of detecting both normal force and tangential force. The sensor's single cell consists of a columnar feeler and 2-by-2 conical feelers. We have derived equations to precisely estimate the three-axis force from the area-sum and area-difference of the conical feelers' contact areas by taking into account wrench-length shrinkage caused by a vertical force. To evaluate the equations and determine constants included in the equations, we performed a series of calibration experiments using a manipulator-mounted tactile sensor and a combined load-testing machine. Subsequently. to evaluate the tactile sensor's practicality. it was mounted on the end of a robotic manipulator which rubbed flat specimens such as brass plates with step-heights of δ=0.05, 0.1, 0.2 mm and a brass plate with no step-height. We showed from the experimental data that the optical three-axis tactile sensor can detect not only the step-heights but also the distribution of the coefficient of friction, and that the sensor can detect fine plate inclination with accuracy to about ±0.4°.


2020 ◽  
Vol 65 (3) ◽  
pp. 205
Author(s):  
I. A. Lyashenko ◽  
Z. M. Liashenko

The influence of a tangential displacement on the strength of the adhesive contacts between gradient materials with different gradings of their properties has been studied. Variants with a controlled force (fixed load) and a controlled displacement (fixed grips) are considered. A relationship between the normal and tangential critical force components at which the contact is destroyed is obtained. It is valid within the whole interval of the gradient parameters, where the detachment criterium is obeyed. The optimal parameters at which the adhesive contact strength is maximum are determined. A case of detachment under the action of only the tangential force, i.e. when the normal force equals zero, is analyzed separately.


2009 ◽  
Vol 16-19 ◽  
pp. 1143-1148
Author(s):  
Yi Qing Yu ◽  
Yuan Li ◽  
Xi Peng Xu

Experimental studies were undertaken to investigate the mechanisms for circular sawing of refractory bricks with diamond segmented saw blades. Three kinds of diamond segments of different hardness were fabricated for the saw blades. The vertical and horizontal force components and the spindle power were measured in sawing. Based on the measurements of force and power, the specific energy and the normal force per diamond grit were obtained. The normal force per grit in the sawing of refractory bricks was found to be only 5% of the static compressive strength of diamonds used in the present study, but fractures of diamonds were still popular on the segment working surfaces after sawing. The power, horizontal force, and the specific energy were found to increase with segment hardness. The specific energy obtained from the measured power was basically comparable to the values obtained from a theoretical equation to calculate the specific energy associated with slurry erosion to the bond matrix of segments.


Author(s):  
N Balasubramanyam

Abstract: Diamond tools are currently being used by an increasing number of architects, miners and construction engineers because they are faster and easier to use than older, more traditional instruments like sledge hammers and pneumatic and hydraulic jacks. Bridge and highway surfaces are cut with diamond asphalt and concrete cutting machines to provide for quick, clean, and easy section removal and replacement. The entire cost is reduced since diamond tools take less time and manpower The experiment is carried out to validate the performance of diamond saw blades by taking into consideration characteristics such as normal force, tangential force, cutting speed, cut depth, and peripheral velocity. In present exploration work we are introductory phase of plan conclusion of a jewel device cutting edge with various segmental like 8,12,16,20 corn meal by utilizing Solid works programming we are planning the apparatus cutting edge after that we are imported in Ansys Software for Analysis reason. Computing the necessary qualities for examination and estimations of earthenware tiles likewise are some other stone molecule. Another power model of cutting is presented and inferred numerical demonstrating for chip thickness. Identical chip thickness to coarseness space proportion is gotten from the new power model another outspread opening like profile is presented. Fragmented sort jewel saw sharp edge with the measurement of 400 mm and different portion, for example, 8, 12, 16 and 20 are planned in Solid works effectively. An examination study between existing roundabout outspread space and cone like opening is done to decide deformity, stress dispersion, vibration and temperature conveyance.


2004 ◽  
Vol 471-472 ◽  
pp. 77-81 ◽  
Author(s):  
Xi Peng Xu ◽  
Y.B. Hong ◽  
S. Chen

An investigation is reported of the performance of diamond impregnated segments in three machining processes - circular sawing of granite with diamond segments, dressing of diamond segments with refractory bricks and surface grinding of diamond segments with an alumina wheel. Two kinds of segments were fabricated by incorporating diamonds (either coated or uncoated) into an iron-based bond matrix. Measurements were made of the horizontal and vertical force components in the machining processes. SEM was used to examine the diamond-matrix bonding states and the ground surfaces of the segments. The changes of forces and segment wear (weight loss and wear performance) were found to be basically consistent for the three machining processes.


Author(s):  
Claude Lechene

Electron probe microanalysis of frozen hydrated kidneysThe goal of the method is to measure on the same preparation the chemical elemental content of the renal luminal tubular fluid and of the surrounding renal tubular cells. The following method has been developed. Rat kidneys are quenched in solid nitrogen. They are trimmed under liquid nitrogen and mounted in a copper holder using a conductive medium. Under liquid nitrogen, a flat surface is exposed by sawing with a diamond saw blade at constant speed and constant pressure using a custom-built cryosaw. Transfer into the electron probe column (Cameca, MBX) is made using a simple transfer device maintaining the sample under liquid nitrogen in an interlock chamber mounted on the electron probe column. After the liquid nitrogen is evaporated by creating a vacuum, the sample is pushed into the special stage of the instrument. The sample is maintained at close to liquid nitrogen temperature by circulation of liquid nitrogen in the special stage.


2018 ◽  
Vol 2 (4) ◽  
pp. 80 ◽  
Author(s):  
Mir Molaie ◽  
Ali Zahedi ◽  
Javad Akbari

Currently, because of stricter environmental standards and highly competitive markets, machining operations, as the main part of the manufacturing cycle, need to be rigorously optimized. In order to simultaneously maximize the production quality and minimize the environmental issues related to the grinding process, this research study evaluates the performance of minimum quantity lubrication (MQL) grinding using water-based nanofluids in the presence of horizontal ultrasonic vibrations (UV). In spite of the positive impacts of MQL using nanofluids and UV which are extensively reported in the literature, there is only a handful of studies on concurrent utilization of these two techniques. To this end, for this paper, five kinds of water-based nanofluids including multiwall carbon nanotube (MWCNT), graphite, Al2O3, graphene oxide (GO) nanoparticles, and hybrid Al2O3/graphite were employed as MQL coolants, and the workpiece was oscillated along the feed direction with 21.9 kHz frequency and 10 µm amplitude. Machining forces, specific energy, and surface quality were measured for determining the process efficiency. As specified by experimental results, the variation in the material removal nature made by ultrasonic vibrations resulted in a drastic reduction of the grinding normal force and surface roughness. In addition, the type of nanoparticles dispersed in water had a strong effect on the grinding tangential force. Hybrid Al2O3/graphite nanofluid through two different kinds of lubrication mechanisms—third body and slider layers—generated better lubrication than the other coolants, thereby having the lowest grinding forces and specific energy (40.13 J/mm3). It was also found that chemically exfoliating the graphene layers via oxidation and then purification prior to dispersion in water promoted their effectiveness. In conclusion, UV assisted MQL grinding increases operation efficiency by facilitating the material removal and reducing the use of coolants, frictional losses, and energy consumption in the grinding zone. Improvements up to 52%, 47%, and 61%, respectively, can be achieved in grinding normal force, specific energy, and surface roughness compared with conventional dry grinding.


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