Abrasive Grain Efficiency and Surface Roughness in Machining Magnesium Alloys by Newly Developed Cup-Type Diamond-Grinding-Wheels

2009 ◽  
Vol 620-622 ◽  
pp. 769-772
Author(s):  
Tien Dong Nguyen ◽  
Koji Matsumaru ◽  
Masakazu Takatsu ◽  
Kozo Ishizaki
Keyword(s):  
Surface Roughness ◽  
Magnesium Alloys ◽  
Unit Length ◽  
Grinding Wheel ◽  
Light Metals ◽  
Grinding Wheels ◽  
Wheel Surface ◽  
Abrasive Grains ◽  
Diamond Grinding ◽  
Abrasive Grain

New cup-type diamond-grinding-wheels with hexagonal pattern have been developed. Grinding stone ratio, R is defined as the ratio between the hexagonal edge area containing abrasive grains and the total area of the wheel surface. In the present work, four kinds of hexagonal grinding wheels with different R (13 %, 19 %, 25 % and 36 %) and a conventional wheel (R: 100 %) were used to grind a light metals, which was represented by magnesium alloy AZ31B. Efficiency of abrasive grains and ground surface for machining a light metals were evaluated by calculating the number of abrasive grains which pass through a unit length of a sample surface for each grinding pass, Ng. The results show that surface roughness becomes smaller, i. e., smoother surfaces as Ng increases. Surfaces ground by the conventional wheel are rougher than those by using newly developed hexagonal grinding-wheels in spite of the larger Ng for the conventional wheel. Surface roughness data forms one curve in roughness vs. Ng graph for all hexagonal wheels, and forms another curve for the conventional grinding-wheel. The difference of two curves indicates that the number of effective working abrasive grains in hexagonal wheels is about 5 times higher than that of the conventional wheel. The similar results were obtained for machining sapphire according to our previous work. Hexagonal wheels show higher abrasive grain efficiency for machining not only hard-to-machine ceramics but also light metals such as magnesium alloys than conventional wheels.

Surface Quality Analysis in Mill-Grinding of SiCp/Al

2011 ◽  
Vol 299-300 ◽  
pp. 1060-1063 ◽  
Author(s):  
Y.X. Yao ◽  
Jin Guang Du ◽  
Jian Guang Li ◽  
H. Zhao
Keyword(s):  
Surface Roughness ◽  
Feed Rate ◽  
Surface Defect ◽  
Quality Analysis ◽  
Grinding Wheel ◽  
Grinding Wheels ◽  
Machined Surface ◽  
Diamond Grinding Wheel ◽  
Diamond Grinding ◽  
Machined Surface Roughness

Mill-grinding experiments were carried out on SiCp/Al to investigate effects of mill-grinding parameters and grinding wheel parameters on machined surface roughness in this paper. The machined surface topography was also analyzed. Experimental results show that surface roughness increases with increasing feed rate and the depth of the mill-grinding. The effect of mill-grinding speed on surface roughness is low. The machined surface reveals many defects. The fine grit diamond grinding wheel can reduce the surface roughness and decrease the machined surface defect. Compared to the vitrified bonded diamond and electroplated diamond grinding wheels used in the experiment, the resin-based diamond grinding wheel produces a better surface.

Prediction of Blunting Area of Abrasive Grains on a Grinding Wheel

2017 ◽  
Vol 139 (12) ◽  
Author(s):  
Aleksandr A. Dyakonov ◽  
Dmitrii V. Ardashev
Keyword(s):  
Cutting Speed ◽  
Mathematic Model ◽  
Grinding Wheel ◽  
Grinding Wheels ◽  
Wheel Wear ◽  
Abrasive Wheel ◽  
Abrasive Grains ◽  
Abrasive Grain ◽  
Mass Transfer Theory ◽  
First Time

The article presents the results of calculating the blunting area of abrasive grains of grinding wheels, determined in accordance with the previously developed model. The mathematic model of the size of the blunting area of an abrasive grain considers the main mechanisms of its wear—mechanical and physicochemical. These mechanisms are taken into account in the model. For the first time, the kinetic theory of strength was used for determining the mechanical wear of abrasive grain. The mass transfer theory was used to study the physicochemical wear: coefficients of chemical affinity with the abrasive material are experimentally defined for the assortment of workpiece materials. The developed mathematic model is a multiple-factor one and this will allow to predict the size of wear of the abrasive wheel for different technological conditions. Also, the article presents the experimental method for determining the blunting area of abrasive grains of grinding wheels, which allows making a direct measurement of wear parameters of grinding wheels. The main parameter of grinding wheel wear is the length of the blunting area of the grain, which was measured out in the direction of the cutting speed vector. The grinding wheels of different graininess were studied—F60 and F46. The grinding wheel working surface was studied by numerical photos and microscope. The results of these experiments have confirmed the adequacy of the design model.

Feasibility Study on Near-Dry Electrical Discharge Dressing of Metal Bonded Diamond Grinding Wheels

2009 ◽  
Author(s):  
Y. Jia ◽  
C. J. Wei ◽  
B. S. Kim ◽  
D. J. Hu ◽  
J. Ni
Keyword(s):  
Electrical Discharge ◽  
Grinding Wheel ◽  
Grinding Wheels ◽  
Wheel Surface ◽  
Rotating Speed ◽  
Diamond Grinding ◽  
Electrode Shape ◽  
Experimental Parameters ◽  
Discharge Parameters ◽  
Electrical Discharge Dressing

Diamond grinding wheels are important tools to carry out precise or ultra-precise grinding of difficult-to-machine materials; however, the difficulty of dressing diamond grinding wheels is a bottleneck problem in their wide application. The objective of this study is to identify the feasibility of near-dry electrical discharge dressing (EDD) of metal bonded diamond grinding wheels. Through design of experiment (DoE), sets of tests were carried out to select proper dielectric mist composition and electrode material, to quantify the dielectric mist composition, to choose the electrode shape and rotating speed, and to investigate the influence of electric discharge parameters on dressing performance. By applying optimized experimental parameters to near-dry EDD of metal bonded diamond grinding wheels, more diamond grits protruded out of the grinding wheel surface, and the worn diamond grinding wheel got sharpened.

Observation of Abrasive Grains Behavior in Contact Area of Grinding Wheel and Comparison with Grinding Wheel Model

2008 ◽  
Vol 389-390 ◽  
pp. 48-54
Author(s):  
Taisei Yamada ◽  
Hwa Soo Lee
Keyword(s):  
Contact Area ◽  
Grinding Wheel ◽  
Grinding Wheels ◽  
Grinding Forces ◽  
Elastic Deformations ◽  
Contact Areas ◽  
Abrasive Grains ◽  
Abrasive Grain ◽  
Wheel Model

In contact areas between grinding wheels and workpieces, elastic deformations of grinding wheel take place due to the act of grinding forces. Since grinding wheels consist of abrasive grains and bonds, it may be regarded that the elastic deformations of grinding wheels in contact areas depend on movements of each abrasive grain. However, plural grains are connected each other complicatedly, and then it is difficult to observe each grain behavior. This study aims to directly observe the behaviors of grains in contact areas with workpieces. A small loading apparatus for grinding wheel is newly developed. Inserting a loaded wheel with this apparatus into SEM, grains behaviors in contact area are directly observed. Furthermore, grains behaviors under loaded condition are analyzed with a wheel model developed previously and observed results are compared with analyzed results.

Improvement of Surface Roughness with Micro-Axial Vibration of Spindle by Pressure Pulsation of Grinding Fluid Supplied through inside of Wheel

2016 ◽  
Vol 1136 ◽  
pp. 673-677
Author(s):  
Kosaku Nomura ◽  
Naoya Takeuchi ◽  
Atsushi Kusakabe ◽  
Masahisa Chino ◽  
Hiroyuki Sasahara
Keyword(s):  
Surface Roughness ◽  
Grain Size ◽  
Pressure Pulsation ◽  
Grinding Wheel ◽  
Axial Vibration ◽  
Machined Surface ◽  
Plunger Pump ◽  
Abrasive Grains ◽  
Abrasive Grain ◽  
Grinding Fluid

In grinding, the moving trajectories of abrasive grains are almost straight to the motion of the rotation and feed of the grinding wheel, so that grinding marks are formed continuously. As a result, surface roughness is dependent on grain size and organization of the grinding wheel. If the trajectory of the abrasive grain is wavy, the peak lines of the grinding marks will be partially removed by following the abrasive grain. This improves surface roughness. The objective of this study is to develop a mechanism to give axial vibration to the grinding wheel by the pulsation of the plunger pump, and thus to improve the surface roughness of the machined surface.

scholarly journals Performance of Norton Quantum Grinding Wheels

2016 ◽  
Vol 686 ◽  
pp. 125-130 ◽  
Author(s):  
Miroslav Neslušan ◽  
Jitka Baďurová ◽  
Anna Mičietová ◽  
Maria Čiliková
Keyword(s):  
Surface Roughness ◽  
Ground Surface ◽  
Bearing Steel ◽  
Grinding Wheel ◽  
Grinding Wheels ◽  
Grinding Forces ◽  
Removal Rates ◽  
Surface Burn ◽  
Conventional Grinding

This paper deals with cutting ability of progressive Norton Quantum grinding wheel during grinding roll bearing steel 100Cr6 of hardness 61 HRC. Cutting ability of this wheel is compared with conventional grinding wheel and based on measurement of grinding forces as well as surface roughness. Results of experiments show that Norton Quantum grinding wheels are capable of long term grinding cycles at high removal rates without unacceptable occurrence of grinding chatter and surface burn whereas application of conventional wheel can produce excessive vibration and remarkable temper colouring of ground surface. Moreover, while Norton Quantum grinding wheel gives nearly constant grinding forces and surface roughness within ground length at higher removal rates, conventional grinding wheel (as that reported in this study) does not.

Surface and Sub-Surface Integrity of Ultra- Machined BK7 Using Fine and Coarse Grained Diamond Wheels

2007 ◽  
Vol 359-360 ◽  
pp. 234-238 ◽  
Author(s):  
Qing Liang Zhao ◽  
Bo Wang ◽  
Ekkard Brinksmeier ◽  
Otmann Riemer ◽  
Kai Rickens ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Surface Integrity ◽  
High Surface ◽  
Coarse Grained ◽  
Nanometer Scale ◽  
Grinding Wheels ◽  
Fine Grained ◽  
Optical Glasses ◽  
Diamond Grinding ◽  
Surface Damages

This paper aims to evaluate the surface and sub-surface integrity of optical glasses which were correspondingly machined by coarse and fine-grained diamond grinding wheels on Tetraform ‘C’ and Nanotech 500FG. The experimental results show that coarse-grained diamond grinding wheels are capable of ductile grinding of optical glasses with high surface and sub-surface integrity. The surface roughness values are all in nanometer scale and the sub-surface damages are around several micros in depth, which is comparative to those machined by fine-grained diamond wheels.

The Three-Dimensional Surface Topographic Characterisation of Diamond Grinding Wheels

2010 ◽  
Vol 126-128 ◽  
pp. 690-695
Author(s):  
David Lee Butler
Keyword(s):  
Measurement Techniques ◽  
Three Dimensional ◽  
Surface Measurement ◽  
Grinding Wheel ◽  
Profile Measurement ◽  
Detailed Knowledge ◽  
Grinding Wheels ◽  
Diamond Grinding ◽  
Insight Into ◽  
Dimensional Surface

Surface measurement using three-dimensional stylus instruments is a relatively new technique that offers numerous advantages over more traditional profilometry methods. The information generated is, unlike profile measurement, less subjective and more statistical providing additional insight into the surface structure. One application of surface measurement that has encountered problems when using the profilometry method is that of grinding wheel characterisation. The wheel surface texture (topography) and the conditions under which it is generated have a profound effect upon the grinding performance as characterised by the grinding forces, power consumption, temperature, and surface integrity of components. A detailed knowledge of the nature of the topography of the grinding wheel would provide further insight into surface interactions between the wheel and workpiece as well as enabling improved control of the grinding process in general. In this paper four diamond grinding wheels of 91 and 181 micron grit size were subjected to differing dressing conditions to produce varying final wheel topographies. Three-dimensional surface measurement techniques were employed to quantitatively characterise the topographic change and provide an aerial estimation of the number of cutting grains. The results demonstrate that the techniques can distinguish between a worn and dressed wheel. In addition, the parametric values generated from the various surfaces can aid the user in determining when re-dressing is required.

Characteristics of the Wheel Surface Topography in Ultra-precision Grinding of Silicon Wafers

2008 ◽  
Vol 389-390 ◽  
pp. 36-41
Author(s):  
Feng Wei Huo ◽  
Dong Ming Guo ◽  
Ren Ke Kang ◽  
Zhu Ji Jin
Keyword(s):  
Surface Topography ◽  
Sampling Interval ◽  
Grinding Wheel ◽  
Height Distribution ◽  
Wheel Surface ◽  
Diamond Grinding Wheel ◽  
Diamond Grinding ◽  
Cutting Surface ◽  
Ultra Precision ◽  
Cutting Direction

A 3D profiler based on scanning white light interferometry with a lateral sampling interval of 0.11μm was introduced to measure the surface topography of a #3000 diamond grinding wheel, and a large sampling area could be achieved by its stitching capability without compromising its lateral or vertical resolution. The protrusion height distribution of diamond grains and the static effective grain density of the grinding wheel were derived, and the wheel chatter and the deformation of the wheel were analyzed as well. The study shows that the grain protrusion height obeys an approximate normal distribution, the static effective grain density is much lower than the theoretical density, and only a small number of diamond grains are effective in the grinding process with fine diamond grinding wheel. There exists waviness on the grinding wheel surface parallel with the wheel cutting direction. The cutting surface of the grinding wheel is not flat but umbilicate, which indicates that the elastic deformation at the wheel edges is much larger than in the center region.

Sign in / Sign up

Export Citation Format

Share Document