Forces in Surface Grinding of Granites with a Brazed Diamond Wheel

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.

2009 ◽  
Vol 404 ◽  
pp. 149-156
Author(s):  
Xi Peng Xu ◽  
X.W. Zhu ◽  
Yuan Li

An experimental study was undertaken to investigate the grinding of granite at different grinding speeds over a wide range of material removal rates. A metal-bonded diamond blade was used as the grinding wheel with natural gray granite as the workpiece material. The tangential and normal force components were obtained through measuring the horizontal and vertical force components as well as the consumed power. The experiments were conducted with a constant wheel surface state to study the influence of grinding speed under different material removal rates. An additional test was also carried out to examine the grinding process while the wheel surface state progressively changed, in which case both forces and the morphologies of diamond grains were monitored at regular intervals. At a fixed material removal rate, both the tangential and normal forces reduced slightly with the grinding speed. But the specific energy increased greatly at higher grinding speeds especially at a shallower maximum grain depth of cut.


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.


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.


2004 ◽  
Vol 471-472 ◽  
pp. 625-629 ◽  
Author(s):  
Yi Qing Yu ◽  
Yuan Li ◽  
Xi Peng Xu

An investigation is reported of the characteristics of specific energy in grinding of granite using diamond abrasives. The effects of many parameters, such as the types of diamond tools, the types of abrasives, the properties of granite, the conditions of lubrication, and the working conditions of diamond tools, were studied. The power consumed in grinding was measured in order to obtain the specific energy, which is defined as the energy expended per unit volume of material removal. It is found that the specific energy for grinding of granite was closely related to the removal mechanisms of granite, the failure modes of diamonds and the interactions of the swarf with the applied fluid and bond matrix.


2016 ◽  
Vol 1136 ◽  
pp. 66-70
Author(s):  
Mei Qin Zhang ◽  
Yi Qing Yu ◽  
Guo Qin Huang ◽  
Xi Peng Xu

An investigation was undertaken to explore the grinding characteristics in grinding of yttrium vanadata (YVO4) crystal by using a resin diamond wheel. The grinding forces and surface roughness were measured and the morphological features of ground workpiece surfaces were examined. The results indicate that the depth of cut is the leading factor in affecting grinding forces whereas the surface roughness is mainly governed by the grinding speed. The material removal mechanism was found to be dominated by brittle fracture mode at conventional grinding speeds, and gradually transfer to ductile flow mode under higher grinding speeds, which is greatly related to the maximum undeformed chip thickness.


2005 ◽  
Vol 291-292 ◽  
pp. 85-90 ◽  
Author(s):  
Xi Peng Xu ◽  
Q.L. Han ◽  
Yuan Li

In this present work, an experimental study was carried out to investigate the wear of metal-bonded diamond tools (specimens) in five abrasive processes – stirring diamond specimens in rock slurries and surface grinding the specimens with a vitrified alumina wheel as well as circular sawing of refractory bricks, vitrified silicon carbide wheels and natural granite with segmented diamond blades. Three diamond specimens of different hardness were fabricated by hot pressing. In addition to following the worn morphologies of the diamond tools, forces and power were also monitored in four abrasive processes. During stirring and surface grinding, the wear of the diamond specimens decreased with increasing specimen hardness, whereas the vertical force in surface grinding increased with the specimen hardness. In sawing of granite, however, the wear of the blades was closely related to the vertical force generated in sawing rather than the hardness of the diamond segments. The trends of force changes in sawing of refractory bricks were comparable to those in sawing of granite. But the force ratios in sawing of the SiC wheel were found to be much higher than those in sawing of other two materials.


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.


1994 ◽  
Vol 116 (3) ◽  
pp. 423-429 ◽  
Author(s):  
J. C. Wang ◽  
S. M. Hsu

Ceramics are hard and brittle. Machining such materials is time-consuming, difficult, and expensive. Current machining technology requires stiff machine, high hardness tools, and small material removal rates to minimize surface damage. This study demonstrates the feasibility of a novel ceramic machining concept that utilizes chemical reactions at the tool-workpiece interface to reduce the stress and minimize the surface damage. A series of cutting tests using a diamond wheel on silicon nitride with different chemical compounds has been performed. The results demonstrate that by using different chemistries, the material removal rate and the surface finish of the machined ceramic can be significantly altered. Some halogenated hydrocarbons show a significant improvement over some commercial machining fluids currently in use.


Author(s):  
A. Sepehri ◽  
K. Farhang

Three dimensional elastic-plastic contact of two nominally flat rough surfaces is by developing the equations governing the shoulder-shoulder contact of asperities based on the Chang, Etsion and Bogy (CEB) model of contact in which volume conservation is assumed in the plastic flow regime. Shoulder-shoulder asperity contact yields a slanted contact force consisting of both tangential (parallel to mean plane) and normal components. Each force component comprises elastic and elastic-plastic parts. Statistical summation of normal force components leads to the derivation of the normal contact force for the elastic-plastic contact akin to the CEB model. Half-plane tangential force due to elastic-plastic contact is derived through the statistical summation of tangential force component along an arbitrary tangential direction.


2016 ◽  
Vol 874 ◽  
pp. 291-296 ◽  
Author(s):  
Lin Li ◽  
Jun Wang ◽  
Huai Zhong Li

An experimental study is reported to characterise the femtosecond (FS) laser grooving process for Germanium (Ge) substrates. The effects of process parameters, including laser fluence, pulse repetition rate and scan speed, on the groove characteristics, material removal rate (MRR) and heat affected zone (HAZ) size are discussed. It is shown that with properly selected process parameters, high quality micro-grooves can be obtained on Ge wafers. Recommendations are finally made on the selection of the most appropriate process parameters for FS micro-grooving of Ge substrates.


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