Ultra-precision face grinding with constant pressure, lapping kinematics, and SiC grinding wheels dressed with overlap factor

2015 ◽  
Vol 79 (9-12) ◽  
pp. 1531-1543 ◽  
Author(s):  
Arthur Alves Fiocchi ◽  
Carlos Alberto Fortulan ◽  
Luiz Eduardo de Angelo Sanchez
Keyword(s):  
Constant Pressure ◽  
Grinding Wheels ◽  
Ultra Precision ◽  
Overlap Factor ◽  
Face Grinding

Five-Axis CNC Tool Grinding: Part I—Rake Face Grinding

2011 ◽  
Author(s):  
Mahmoud M. Rababah ◽  
Zezhong C. Chen
Keyword(s):  
Rake Angle ◽  
Grinding Process ◽  
Rake Face ◽  
End Mill ◽  
Grinding Wheels ◽  
Robust Algorithm ◽  
Geometric Representations ◽  
Five Axis ◽  
Face Grinding ◽  
Tool Grinding

Grinding the helical surfaces in end-mill cutters using two-axis CNC machines is well investigated in literature. However, the grinding wheels do not have explicit geometric representations and the produced helical angles differ from the designed values. Moreover, to the best knowledge of the authors, no reliable and robust algorithm exists to grind generic shape cutters with constant normal rake angles. Thus, the first part of this work introduces a five-axis grinding process that keeps the normal rake angle constant along the rake face. The parameters that affect the shape of the tool flutes are also analyzed and studied in this part. These parameters are then optimized in the second part to obtain optimum wheel shapes grinding the tool flutes along optimum paths. Overall, the grinding process proposed grinds the tool flutes with close matching to the designed ones and replaces the complex wheel shapes commonly used by simple prismatic ones.

New Tool Concepts for Ultra-Precision Grinding

2012 ◽  
Vol 516 ◽  
pp. 287-292 ◽  
Author(s):  
Ekkard Brinksmeier ◽  
Yildirim Mutlugünes ◽  
Grigory Antsupov ◽  
Kai Rickens
Keyword(s):  
Surface Roughness ◽  
Wear Resistance ◽  
Surface Finish ◽  
Cvd Diamond ◽  
Coarse Grained ◽  
Grinding Wheels ◽  
Precision Grinding ◽  
Diamond Grinding ◽  
Ultra Precision ◽  
Sharp Edges

This paper presents advanced tools for ultra precision grinding which offer a high wear resistance and can be used to generate high-quality parts with an ultraprecise surface finish. The first approach features defined dressed, coarse-grained, single layered, metal bonded diamond grinding wheels. These grinding wheels are called Engineered Grinding Wheels and have been dressed by an adapted conditioning process which leads to uniform abrasive grain protrusion heights and flattened grains. This paper shows the results from grinding optical glasses with such Engineered Grinding Wheels regarding the specific forces and the surface roughness. The results show that the cutting mechanism turns into ductile removal and optical surfaces are achievable. On the other hand, the specific normal force F´n increases due to increased contact area of the flattened diamond grains. It is shown that the topography of the Engineered Grinding Wheels has a strong beneficial influence on surface roughness. The second new tool for ultra precision grinding is made of a CVD (Chemical Vapour Deposition) poly-crystalline diamond layer with sharp edges of micrometre-sized diamond crystallites as a special type of abrasive. The sharp edges of the crystallites act as cutting edges which can be used for grinding. It is shown that by using CVD-diamond-coated grinding wheels a high material removal rate and a high surface finish with surface roughness in the nanometre range can be achieved. The CVD-diamond layers exhibit higher wear resistance compared to conventional metal and resin bonded diamond wheels. In conclusion, this paper shows that not only conventional fine grained, multi-layered resinoid diamond grinding wheels but also coarse-grained and binderless CVD-coated diamond grinding wheels can be applied to machine brittle and hard materials by ultra precision grinding.

Slot and Vertical Face Grinding of Aerospace Components

1996 ◽  
Vol 118 (3) ◽  
pp. 620-625
Author(s):  
R. B. Mindek ◽  
T. D. Howes
Keyword(s):  
Heat Input ◽  
Thermal Damage ◽  
Cubic Boron Nitride ◽  
Grinding Wheel ◽  
Grinding Wheels ◽  
Grinding Forces ◽  
Wheel Wear ◽  
Inconel 713C ◽  
Profile Accuracy ◽  
Face Grinding

Workpiece profile accuracy, wheel wear, and thermal damage were investigated for the grinding of slots and vertical faces on MAR-M-247, Inconel 713C, and M-2 tool steel using both alumina and cubic boron nitride (CBN) grinding wheels. It was found when grinding with alumina wheels that the wheel corner and first 2.5 mm of the grinding wheel sidewall account for all the grinding forces in the vertical, horizontal, and transverse directions, and therefore is responsible for all the significant grinding done on the sideface of the workpiece. Since previous work links wheel wear and workpiece thermal damage during grinding to grinding forces, this finding suggests that the area around the wheel corner is the critical region of importance in grinding these types of profiles in terms of wheel wear and the heat input to the workpiece. These, in turn, are linked to workpiece profile accuracy and metallurgical damage. Results also show that striation marks inherent in sidewall grinding can be minimized by controlling the maximum normal infeed rate of the wheel. A method for minimizing the heat input into the workpiece by minimizing grinding force during vertical face grinding is also reported.

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