Pitch polishing of silica: correlation between material removal rates and surface finishes

2007 ◽  
Author(s):  
I. Roberts ◽  
P. Murray ◽  
W. Williams ◽  
A. Landis ◽  
B. Mullany
Keyword(s):  
Material Removal ◽  
Removal Rates ◽  
Surface Finishes

Feasibility Study on Grinding of Titanium Alloys with Electroplated CBN Wheels

2013 ◽  
Vol 797 ◽  
pp. 73-78 ◽  
Author(s):  
Zhong De Shi ◽  
Helmi Attia
Keyword(s):  
Titanium Alloy ◽  
Titanium Alloys ◽  
Material Removal ◽  
High Pressures ◽  
Surface Cleaning ◽  
Depth Of Cut ◽  
Wheel Surface ◽  
Removal Rates ◽  
Grinding Fluid ◽  
Creep Feed

An experimental investigation is reported on the grinding of a titanium alloy using electroplated CBN wheels with water-based grinding fluid and wheel surface cleaning fluid applied at high pressures. This work was motivated by applying grinding fluid and wheel surface cleaning fluid both at high pressures for avoiding wheel loading, which is commonly seen in titanium alloy grinding. The objective is to explore the feasibility to grind titanium alloys with electroplated CBN wheels and high pressure wheel surface cleaning fluid for enhancing material removal rates. Straight surface grinding experiments were conducted on titanium alloy blocks in both shallow depth of cut and creep-feed modes. Grinding power, forces, and surface roughness were measured. Specific material removal rates of 8 mm2/s in shallow cut mode and 3 mm2/s at a depth of cut as high as 3 mm in creep-feed mode were achieved without burning and smearing of ground surfaces. It was showed that it is feasible to grind titanium alloys with electroplated CBN wheels at enhanced removal rates by applying grinding and wheel cleaning fluid at high pressures.

The Material Removal Mechanism in Magnetic Fluid Grinding of Ceramic Ball Bearings

1994 ◽  
Vol 208 (1) ◽  
pp. 47-59 ◽  
Author(s):  
T H C Childs ◽  
S Mahmood ◽  
H J Yoon
Keyword(s):  
Magnetic Fluid ◽  
Material Removal ◽  
Permanent Magnets ◽  
Experimental Studies ◽  
Wear Coefficient ◽  
Rotating Shaft ◽  
Removal Rates ◽  
Kinematic Theory ◽  
New Process ◽  
A Cell

Recently a new process known as magnetic fluid grinding has been developed in Japan which can remove material in the finishing of ceramic balls some fifty times more rapidly than can the lapping processes that are conventionally used. Balls are driven round a cell by a rotating shaft in an arrangement similar to a thrust race but submerged in a magnetic fluid placed above permanent magnets. The magnets and fluid create buoyancy forces that levitate grinding grits in the fluid and also provide the loads for the process, but it is not clear why the process is more effective than lapping. This paper reports on experimental studies of the grinding rates of silicon nitride balls in magnetic fluids loaded with diamond grits and of the motion of the balls through the fluids. The high removal rates occur when skidding occurs between the balls and drive shaft. A kinematic theory is developed to calculate sliding speeds and is used to deduce an abrasive wear coefficient for the process of 0.07 ± 0.02, indicative of two-body abrasion. The high removal rates are a consequence of the large sliding speeds that can be developed, of several metres per second.

Mathematical Model for Chip Serration Frequency in Turning of Stainless Steel with Magnetic Damping from Bottom of Tool Shank

2013 ◽  
Vol 393 ◽  
pp. 108-114
Author(s):  
A.K.M. Nurul Amin ◽  
Fawaz Mohsen Abdullah ◽  
Muammer Din Arif ◽  
Israd H. Jaafar
Keyword(s):  
Mathematical Model ◽  
Stainless Steel ◽  
Material Removal ◽  
Control Method ◽  
Research Work ◽  
Chip Morphology ◽  
Work Piece ◽  
Removal Rates ◽  
Serrated Chip ◽  
Tool Shank

Chatter, a violent and often unpredictable relative oscillatory motion between the tool and work-piece, is a serious concern in turning operations. Its occurrence is usually associated with a loud monotonous sound and usually results in increased surface roughness, reduced material removal rates, shortened tool life, and damaged machine-tool bearings. The established theories for chatter are very limited in scope and are often contradicted by empirical evidences. Therefore, chatter avoidance in the past has relied on inefficient techniques like limiting material removal rates or expensive setups such as actuators and ultrasonic vibration damping systems. However, a deeper investigation into chatter formation reveals that chip morphology and segmentation play a significant role during the incidence of chatter. The novel Resonance theory of chatter combines the concept of mode coupling of the machining setup and serrated chip formation, to explain and predict chatter. To validate the postulates of this theory, models for chip serration frequency are essential. At the same time, a reliable and economical chatter control method is required. With this goal, the current research work has developed an empirical mathematical model of chip serration frequency in turning of stainless steel AISI 304 using Response Surface Methodology (RSM). Also, it investigated the influence of damping provided by magnetic field from a permanent ferrite magnet placed beneath the tool shank. The developed chip serration model is in good accord with the experimental data, demonstrating that the empirical model could be used for further chip morphology and chatter analyses.

On-machine truing of diamond wheel and high-efficiency grinding of monocrystal silicon for aspheric surface

2016 ◽  
Vol 231 (1) ◽  
pp. 186-192 ◽  
Author(s):  
Bing Chen ◽  
Bing Guo ◽  
Qingliang Zhao
Keyword(s):  
Surface Quality ◽  
Material Removal ◽  
High Efficiency ◽  
Diamond Wheel ◽  
Experimental Results ◽  
Aspheric Surface ◽  
Removal Rates ◽  
Aspheric Surfaces ◽  
Silicon Carbon

To realize the high-efficiency grinding of the aspheric surfaces on monocrystal silicon, a novel on-machine truing method for the resin-bonded arc-shaped diamond wheels was proposed utilizing rotary green silicon carbon rod, and then the high-efficiency grinding of the aspheric surface was performed. First, the principle of mutual-wear for truing arc-shaped diamond wheel was introduced, and the truing performance was studied. The experimental results showed that the top morphology of the trued arc-shaped wheel was precise and smooth, and the run error on the top of the trued arc-shaped wheel was reduced from 41 to 10 µm after truing. Furthermore, high-efficiency grinding experiments revealed that the surface quality of the aspheric surface increased with the increase in the average material removal rates.

FEM-Based Simulation of Temperature in Speed Stroke Grinding with 3D Transient Moving Heat Sources

2011 ◽  
Vol 223 ◽  
pp. 733-742 ◽  
Author(s):  
Barbara Linke ◽  
Michael Duscha ◽  
Anh Tuan Vu ◽  
Fritz Klocke
Keyword(s):  
Finite Element ◽  
Material Properties ◽  
Material Removal ◽  
Structural Changes ◽  
Numerical Technique ◽  
Temperature Fields ◽  
Fe Model ◽  
Measured Temperature ◽  
Temperature Dependent ◽  
Removal Rates

The grinding process is one of the most important finishing processes to obtain high surface quality. Nowadays, grinding is also considered as a high performance process with high material removal rates. Nevertheless, to avoid thermally-induced structural changes poses a major challenge for this manufacturing technology. Until now, the Finite Element Method (FEM) has been widely applied as a proper numerical technique to predict workpiece properties in machining processes. However, actual models in grinding are limited to conventional grinding processes with simple workpiece profiles and low table speeds. In this paper, finite element simulations are expanded to 3-dimensional (3D) models with temperature-dependent material properties and heat source profiles derived from experimental results, i.e. tangential forces. Both temperature simulation and measurement were conducted for deep grinding, pendulum grinding and speed stroke grinding in the table speed range of vw= 12 m/min to 180 m/min and specific material removal rates of Q’w= 40 mm³/mms. Overall, the simulation results show a good agreement with the measured temperature and surface integrity after grinding. This research indicates that a 3D FE model with temperature dependent material properties can predict realistic temperature fields in speed stroke grinding. Therefore, the experiment and measurement costs and time can be reduced by FEM simulation.

A study of material removal rates for shallow drilling with an ultrashort pulse laser

2009 ◽  
Author(s):  
B. R. Campbell ◽  
L. A. Forster ◽  
J. A. Moore ◽  
T. M. Lehecka ◽  
J. G. Thomas ◽  
...  
Keyword(s):  
Pulse Laser ◽  
Ultrashort Pulse ◽  
Material Removal ◽  
Removal Rates ◽  
Ultrashort Pulse Laser
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