Some Aspects of Flat Surface Grinding with Intermittent Cross-Feed

1979 ◽  
Vol 101 (2) ◽  
pp. 135-146 ◽  
Author(s):  
J. K. Banerjee
Keyword(s):  
Wear Mechanism ◽  
Specific Energy ◽  
Flat Surface ◽  
Grinding Force ◽  
Wheel Wear ◽  
Material Combination ◽  
Force Relation ◽  
Wide Range ◽  
Constant Maximum ◽  
Force Equilibrium

Part I: A Wheel Wear Mechanism. Using a constant maximum grit-force hypothesis for a fixed wheel-work combination, a stable and progressive wear-land model is developed as a function of the machine settings and its mechanical and thermal limitations are discussed. Experiments conducted with several wheel-work materials, both during dry and wet grinding justify the proposed wear mechanism and its limitations with respect to the machine settings. Part II: The Force Equilibrium. Under a stable wear mechanism as proposed in Part I, the grinding force is shown to be a simple linear function of a combined machine settings’ parameter; the slope of the line gives, in the range of the machine settings used, a constant specific energy for a given wheel-work material combination. Thermal expansion as well as grit rubbing, while not necessarily altering the basic wear-land geometry, tend to change this force relation. Experimental results over a wide range of the machine settings and for different wheels and workpieces agree with the force relation, and the specific energy calculated therefrom coincides quantitatively with the other published results on similar workpiece materials.

Creep-Feed Grinding of Tungsten Carbide by Using Resin-Bonded Nickel-Coated Diamond Wheel

2011 ◽  
Vol 325 ◽  
pp. 165-170
Author(s):  
Abbas Pak ◽  
Amir Abdullah
Keyword(s):  
Tungsten Carbide ◽  
Specific Energy ◽  
Diamond Wheel ◽  
Grinding Force ◽  
Technological Parameters ◽  
Wheel Wear ◽  
Creep Feed Grinding ◽  
Creep Feed ◽  
Force Increase ◽  
Machining Operations

Force and specific energy are important factors in all abrasive machining operations especially in creep-feed grinding of hard materials. They have a high influence on the wheel wear, grinding accuracy, grinding temperature and surface integrity. This paper investigates the effect of grinding technological parameters on grinding force and specific energy in up-cut creep-feed grinding of cemented tungsten carbide with 20% cobalt using a resin-bonded nickel-coated diamond wheel. It was observed that increase of feed rate resulted in grinding force increase and specific energy decrease. Increased wheel-peripheral speed resulted in minor decrease of grinding force and specific energy increase.

Investigation on Surface Grinding of Ti-6Al-4V Using Minimum Quantity Lubrication

2012 ◽  
Vol 500 ◽  
pp. 308-313 ◽  
Author(s):  
Guo Qiang Guo ◽  
Zhi Qiang Liu ◽  
Xiao Hu Zheng ◽  
Ming Chen
Keyword(s):  
Surface Roughness ◽  
Plastic Deformation ◽  
Surface Morphology ◽  
Specific Energy ◽  
Minimum Quantity Lubrication ◽  
Grinding Force ◽  
Dry Grinding ◽  
Surface Damages ◽  
Side Flow ◽  
Mql System

This paper investigates the effects of MQL system on the grinding performance of Ti-6Al-4V using SiC abrasive, the evaluation of the performance consisted of analyzing the grinding force, surface roughness and surface morphology. The experiment result indicated that the favorable lubricating effect of MQL oil makes it has the lowest value of grinding force, specific energy and force raito. MQL has better surface finish than dry grinding and fluid grinding has the lowest value of surface roughness under different grinding depth. Surface damages such as: side flow, plastic deformation, redeposition are present in dry and fluid grinding. As grinding depth increased, the damages become much more severe. But in MQL condition, it gives better surface integrity than dry and fluid grinding.

Study on Grinding Machinability of Titanium Alloy Using SiC Abrasive

2011 ◽  
Vol 487 ◽  
pp. 34-38 ◽  
Author(s):  
Guo Giang Guo ◽  
X.H. Zheng ◽  
Z.Q. Liu ◽  
Qing Long An ◽  
Ming Chen
Keyword(s):  
Titanium Alloy ◽  
High Temperature ◽  
Surface Topography ◽  
Specific Energy ◽  
Ground Surface ◽  
Grinding Force ◽  
Grinding Forces ◽  
Grinding Mechanism ◽  
Dry Conditions ◽  
Metallurgical Structure

Experimental results of Ti-6-2-4-2S, Ti-6-4 and Ti-5-5-5-1-1 are detailed in this paper with conventional surface grinding using SiC abrasive under dry conditions. Measurements of grinding forces, surface topography and metallurgical structure of ground surface were taken to investigate the grinding mechanism of these materials. The results showed grinding force ratios to these materials were between 1.35 to 2.25 at all material remove rates, but the specific energy to Ti-5-5-5-1-1 and Ti-6-2-4-2S were little higher than Ti-6-4. Evaluation of ground surface topography indicated they were visually free of crack and burn. At the same grinding parameters, Ti-5-5-5-1-1 had the maximum depth of heat-affected zone because of its poor high temperature properties.

Application of subloading-overstress friction model to finite element analysis

2014 ◽  
Vol 4 (2) ◽  
Author(s):  
T. Kuwayama ◽  
K. Hashiguchi ◽  
N. Suzuki ◽  
N. Yoshinaga ◽  
S. Ogawa
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Flat Surface ◽  
Surface Friction ◽  
Friction Model ◽  
Sliding Velocity ◽  
Element Analysis ◽  
Contact Behaviour ◽  
Wide Range ◽  
The Finite Element Analysis

Accurate prediction of contact behaviour between machine tools and metals is required for the mechanical design of machinery. In this article, the numerical analysis of the contact behaviour is described by incorporating the subloading-overstress model [6] which is capable of describing the contact behaviour for a wide range of sliding velocity including the increase of coefficient of friction with the increase of sliding velocity. And its validity is verified by the comparison with some test results. First, in order to examine the influence of sliding velocities on the friction properties, the flat-surface friction tests for lubricated interfaces between galvannealed steel sheet and SKD-11 tool steel were performed. As a result, It is observed that the friction smoothly translate to kinetic friction, after exhibiting the peak at the static friction. In addition, it is observed that the higher the sliding velocity, the larger the friction resistance, meaning the positive rate sensitivity. Then the subloading-overstress model is implemented in the finite element analysis program ABAQUS/Standard, and it is used to simulate the flat-surface friction tests. The predictions from the finite element analysis are shown to be in very good agreement with experimental results.

scholarly journals Investigation of Error Distribution in the Back-Calculation of Breakage Function Model Parameters via Nonlinear Programming

Minerals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 425
Author(s):  
Jihoe Kwon ◽  
Heechan Cho
Keyword(s):  
Flat Surface ◽  
Error Function ◽  
Model Parameters ◽  
Dimensional Parameter ◽  
Parameter Spaces ◽  
Initial Values ◽  
Wide Range ◽  
Minimum Number ◽  
Breakage Function ◽  
Back Calculation

Despite its effectiveness in determining breakage function parameters (BFPs) for quantifying breakage characteristics in mineral grinding processes, the back-calculation method has limitations owing to the uncertainty regarding the distribution of the error function. In this work, using Korean uranium and molybdenum ores, we show that the limitation can be overcome by searching over a wide range of initial values based on the conjugate gradient method. We also visualized the distribution of the sum of squares of the error in the two-dimensional parameter space. The results showed that the error function was strictly convex, and the main problem in the back-calculation of the breakage functions was the flat surface of the objective function rather than the occurrence of local minima. Based on our results, we inferred that the flat surface problem could be significantly mitigated by searching over a wide range of initial values. Back-calculation using a wide range of initial values yields BFPs similar to those obtained from single-sized-feed breakage tests (SSFBTs) up to four-dimensional parameter spaces. Therefore, by searching over a wide range of initial values, the feasibility of the back-calculation approach can be significantly improved with a minimum number of SSFBTs.

Complex Grinding Assisted with Electrical Discharge Machining for Electrically Conductive PCD

2010 ◽  
Vol 126-128 ◽  
pp. 591-596 ◽  
Author(s):  
Manabu Iwai ◽  
Shinichi Ninomiya ◽  
Gaku Sugino ◽  
Kiyoshi Suzuki
Keyword(s):  
Surface Finish ◽  
Electrical Discharge ◽  
Material Removal ◽  
High Efficiency ◽  
Electrical Discharge Machining ◽  
Grinding Force ◽  
Wheel Wear ◽  
Electrically Conductive ◽  
Composite Diamond

A new PCD material named EC-PCD (Electrically conductive polycrystalline composite diamond), which consists of electrically conductive diamond grits, has recently been developed. This paper deals with an investigation of a complex grinding assisted with electrical discharge machining (EDM) to realize high efficiency, low and stable grinding force and low wheel wear for the new EC-PCD. The effect of complex grinding assisted with EDM is compared experimentally with the standard PCD (S-PCD). The result shows that, in the complex grinding, lower and more stable grinding force is realized thanks to the material removal action in EDM and that lower wheel wear and better surface finish are attained, just when the EC-PCD is selected as a workpiece.

Wear Mechanisms in Grinding of PCBN

2016 ◽  
Vol 1136 ◽  
pp. 555-560 ◽  
Author(s):  
Berend Denkena ◽  
Thilo Grove ◽  
Leif Behrens
Keyword(s):  
Wear Mechanism ◽  
High Hardness ◽  
Economic Benefits ◽  
Production Costs ◽  
Grinding Wheel ◽  
End User ◽  
Wheel Wear ◽  
Steel Cast ◽  
High Feed ◽  
High Production

PCBN-inserts have a high potential in the cutting of hardened steel, cast iron and super alloys due to their high hardness and heat resistance. Nevertheless they have a high purchase price, which lowers the economic benefits for the end user compared to other cutting materials. This is caused by the high production costs of the inserts. The grinding of PCBN-inserts causes a major proportion of these costs as a result of the high grinding wheel wear. The primary wear mechanism is grain breakout followed by clogging of the grinding layer. This study shows that the efficiency of the grinding process can be increased significantly by applying low cutting speeds and high feed rates. In this case, splintering of the grinding grain is the main wear mechanism.

Fuel effects on range versus payload for modern jet aircraft

2011 ◽  
Vol 115 (1172) ◽  
pp. 627-634 ◽  
Author(s):  
S. Blakey ◽  
C. W. Wilson ◽  
M. Farmery ◽  
R. Midgley
Keyword(s):  
Specific Energy ◽  
Hydrocarbon Fuels ◽  
Fuel Properties ◽  
Maximum Payload ◽  
Wide Range ◽  
Maximum Range ◽  
Fuel Effects

Abstract With changes in the availability and quality of existing aviation fuels anticipated in the next 30 years it is timely to assess how changes in fuel properties would affect the range payload performance of aircraft. The effects on range and payload of a wide range of candidate fuels for aviation are investigated, including changes to the blends of conventional hydrocarbon fuels. Lighter fuels tend to be more desirable for commercial flights, where the flight is as close to the maximum payload as possible. Flights favouring range over payload are better suited by a more dense fuel. The hydrocarbon blends suggest for each aircraft, an optimum fuel may exist for the maximum payload and allowing the maximum range. Specific flight plans below the maximum range of the aircraft may be met with a lower specific energy fuel.

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