The Role of Grain Tip Radius in Fine Grinding

1975 ◽  
Vol 97 (3) ◽  
pp. 1119-1125 ◽  
Author(s):  
G. K. Lal ◽  
M. C. Shaw
Keyword(s):  
Grain Size ◽  
Surface Finish ◽  
Chip Thickness ◽  
Radius Of Curvature ◽  
Undeformed Chip Thickness ◽  
Fine Grinding ◽  
Abrasive Grains ◽  
Grinding Conditions ◽  
Tip Radius

The scratches produced by single abrasive grains in overcut fly milling show that the transverse shape of a grain is closely approximated by an arc of a circle. This radius of curvature is found to be independent of grain type and grinding conditions but varies with the grain size. The equation for undeformed chip thickness for surface grinding is rederived in terms of this radius. The important role that the transverse curvature of the grain plays relative to surface finish is also discussed.

Grinding Wheel Elasticity

1971 ◽  
Vol 93 (2) ◽  
pp. 609-613 ◽  
Author(s):  
K. Nakayama ◽  
J. Brecker ◽  
M. C. Shaw
Keyword(s):  
Contact Zone ◽  
Chip Thickness ◽  
Grinding Wheel ◽  
Undeformed Chip Thickness ◽  
Fine Grinding ◽  
Abrasive Grains ◽  
Work Material ◽  
Cutting Surface ◽  
Order Of Magnitude ◽  
Zone Deformation

The deflection of individual abrasive grains in the cutting surface of a vitrified grinding wheel has been postulated to explain many fine grinding results; however, the magnitude of the deflection has never been firmly established. Experiments conducted to measure the deflection associated with an individual grain showed it to be of the same order of magnitude as the undeformed chip thickness. A model of a grinding wheel which allows both the deflection of the center of an individual grain and the deformation in the contact zone between the grain and the work material to be evaluated was developed. Contact zone deformation was found to be approximately twice as great as the deflection of the center of the grain.

Forces and Energy in Circular Sawing and Grinding of Granite

2000 ◽  
Vol 123 (1) ◽  
pp. 13-22 ◽  
Author(s):  
Xipeng Xu ◽  
Yuan Li ◽  
Stephen Malkin
Keyword(s):  
Normal Force ◽  
Tangential Force ◽  
Chip Thickness ◽  
Undeformed Chip Thickness ◽  
Unit Width ◽  
Wide Range ◽  
Grinding Conditions ◽  
Cutting Zone ◽  
Circular Sawing ◽  
Force Components

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.

Surface Grinding Force Model of Steel 55 Based on Undeformed Chip Thickness with CBN Electroplated Wheels

2011 ◽  
Vol 189-193 ◽  
pp. 1768-1773 ◽  
Author(s):  
Jun Ming Wang ◽  
Ren Zhen Ye ◽  
Hui Peng Chen ◽  
Hong Zan Bin
Keyword(s):  
Velocity Ratio ◽  
Influence Factors ◽  
Chip Thickness ◽  
Grinding Force ◽  
Calculation Model ◽  
Surface Grinding ◽  
Force Model ◽  
Undeformed Chip Thickness ◽  
Abrasive Grains ◽  
Random Direction

Undeformed chip thickness is one of the most important parameters in grinding process, which is related to the entire abrasive grains in grinding simultaneously and changed periodically with time. Simplifying the geometric shape of abrasive grains ,the paper modifies the mathematic models of undeformed chip thickness by analytic method, establishes an universal calculation model of grinding force based on undeformed chip thickness, then optimizes the parameters of the model by restrictive random direction method according to the measuring experiments of the inter-grain spacing about CBN electroplated wheels and the grinding experiments of steel 55 during surface grinding, analyses the influence factors of the friction ratio on the grinding force. The results show that under the same grinding depth， both of the ratio and the grinding force will be decreased with the increase of velocity ratio VS/VW, but the ratio increases and the grinding force decreases with the increase of inter-grain spacing.

scholarly journals On the role of grain size on slurry erosion behavior of a novel medium-carbon, low-alloy pipeline steel after induction hardening

Wear ◽  
2021 ◽  
pp. 203678
Author(s):  
Vahid Javaheri ◽  
Oskari Haiko ◽  
Saeed Sadeghpour ◽  
Kati Valtonen ◽  
Jukka Kömi ◽  
...  
Keyword(s):  
Grain Size ◽  
Pipeline Steel ◽  
Induction Hardening ◽  
Slurry Erosion ◽  
Medium Carbon ◽  
Erosion Behavior

Effects of Insert Nose Radius and Processing Cutting Parameter on the Surface Roughness of Aisi 316 Stainless Steel

2010 ◽  
Vol 447-448 ◽  
pp. 51-54
Author(s):  
Mohd Fazuri Abdullah ◽  
Muhammad Ilman Hakimi Chua Abdullah ◽  
Abu Bakar Sulong ◽  
Jaharah A. Ghani
Keyword(s):  
Surface Roughness ◽  
Stainless Steel ◽  
Surface Finish ◽  
Feed Rate ◽  
Cutting Speed ◽  
Chip Thickness ◽  
Cutting Parameters ◽  
Depth Of Cut ◽  
Nose Radius ◽  
Aisi 316

The effects of different cutting parameters, insert nose radius, cutting speed and feed rates on the surface quality of the stainless steel to be use in medical application. Stainless steel AISI 316 had been machined with three different nose radiuses (0.4 mm 0.8 mm, and 1.2mm), three different cutting speeds (100, 130, 170 m/min) and feed rates (0.1, 0.125, 0.16 mm/rev) while depth of cut keep constant at (0.4 mm). It is seen that the insert nose radius, feed rates, and cutting speed have different effect on the surface roughness. The minimum average surface roughness (0.225µm) has been measured using the nose radius insert (1.2 mm) at lowest feed rate (0.1 mm/rev). The highest surface roughness (1.838µm) has been measured with nose radius insert (0.4 mm) at highest feed rate (0.16 mm/rev). The analysis of ANOVA showed the cutting speed is not dominant in processing for the fine surface finish compared with feed rate and nose radius. Conclusion, surface roughness is decreasing with decreasing of the feed rate. High nose radius produce better surface finish than small nose radius because of the maximum uncut chip thickness decreases with increase of nose radius.

scholarly journals Magmatic Focusing to Mid-Ocean Ridges: The Role of Grain-Size Variability and Non-Newtonian Viscosity

2017 ◽  
Vol 18 (12) ◽  
pp. 4342-4355 ◽  
Author(s):  
Andrew J. Turner ◽  
Richard F. Katz ◽  
Mark D. Behn ◽  
Tobias Keller
Keyword(s):  
Grain Size ◽  
Newtonian Viscosity ◽  
Ocean Ridges ◽  
Size Variability

The Role of Cutter Eccentricity on Surface Finish and Milling Forces

2004 ◽  
Author(s):  
Tony L. Schmitz ◽  
Jeremiah Couey ◽  
Eric Marsh ◽  
Michael F. Tummond
Keyword(s):  
Surface Finish ◽  
Milling Machine ◽  
Time Domain Simulation ◽  
Machined Surface ◽  
Premature Failure ◽  
Series Of Experiments ◽  
Error Motion ◽  
Milling Forces ◽  
Chip Load

In this paper, the role of milling cutter eccentricity, commonly referred to as runout, is explored to determine its effects on surface topography and milling forces. This work is motivated by the observation that commercially-available cutter bodies often exhibit variation in the teeth/insert radial locations as a result of manufacturing issues. Consequently, the chip load on individual cutting teeth varies periodically, which can lead to premature failure of the cutting edges. Additionally, this chip load variation increases the roughness of machined surfaces. This research isolates the effect of runout on cutting forces and the machined surface finish in a series of experiments completed on a precision milling machine with 0.1 μm positioning repeatability and 0.02 μm spindle error motion. The runout is varied in a controlled fashion and results compared between experiment and a comprehensive time-domain simulation.

scholarly journals Geometric Analysis of Undeformed Chip Thickness in Ball-Nosed End Milling

2004 ◽  
Vol 47 (1) ◽  
pp. 2-7 ◽  
Author(s):  
Hisanobu TERAI ◽  
Minghui HAO ◽  
Koichi KIKKAWA ◽  
Yoshio MIZUGAKI
Keyword(s):  
End Milling ◽  
Geometric Analysis ◽  
Chip Thickness ◽  
Undeformed Chip Thickness

scholarly journals The Role of Microstructure on the Tensile Plastic Behaviour of Ductile Iron GJS 400 Produced through Different Cooling Rates—Part II: Tensile Modelling

Metals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 1019 ◽  
Author(s):  
Angella ◽  
Donnini ◽  
Ripamonti ◽  
Górny ◽  
Zanardi
Keyword(s):  
Grain Size ◽  
Ductile Iron ◽  
Volume Fraction ◽  
Interlamellar Spacing ◽  
Flow Curves ◽  
Cooling Rates ◽  
Plastic Behaviour ◽  
Microstructure Parameters ◽  
Explicit Correlation

Tensile testing on ductile iron GJS 400 with different microstructures produced through four different cooling rates was performed in order to investigate the relevance of the microstructure’s parameters on its plastic behaviour. Tensile flow curve modelling was carried out with the Follansbee and Estrin-Kocks-Mecking approach that allowed for an explicit correlation between plastic behaviour and some microstructure parameters. In the model, the ferritic grain size and volume fraction of pearlite and ferrite gathered in the first part of this investigation were used as inputs, while other parameters, like nodule count and interlamellar spacing in pearlite, were neglected. The model matched very well with the experimental flow curves at high strains, while some mismatch was found only at small strains, which was ascribed to the decohesion between the graphite nodules and the ferritic matrix that occurred just after yielding. It can be concluded that the plastic behaviour of GJS 400 depends mainly on the ferritic grain size and pearlitic volume fraction, and other microstructure parameters can be neglected, primarily because of their high nodularity and few defects.

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