scholarly journals Discussion: “The Wheel Wear and Metal Removal Mechanisms in Vertical Spindle Abrasive Machining of Mild Steel” (Pollock, C., 1968, ASME J. Eng. Ind., 90, pp. 365–369)

1968 ◽  
Vol 90 (2) ◽  
pp. 369-370
Author(s):  
R. L. Smith
1968 ◽  
Vol 90 (2) ◽  
pp. 365-369 ◽  
Author(s):  
C. Pollock

The primary metal removal mechanisms in vertical spindle abrasive machining are chip removal by firmly bonded abrasive grains in the wheel matrix, and secondary removal by the reuse of loose abrasive between the wheel-work interface. As you increase the strength (go to harder grades) of segments, the secondary metal removal rate tends to remain constant. However, the metal removed by firmly bonded abrasive increases rapidly. Changing from an E to an F grade approximately doubles the primary metal removal rate. Segmental wheels sharpen themselves by two major mechanisms—primary and secondary wear. Primary wear is caused by the common mechanisms of attrition, grain fracture, and bond failure. The secondary mechanism is caused by loose abrasive and metal chips in the wheel-work interface.


2016 ◽  
Vol 102 ◽  
pp. 453-463 ◽  
Author(s):  
Maximilian Huber ◽  
Harald Hilbig ◽  
Sophia C. Badenberg ◽  
Julius Fassnacht ◽  
Jörg E. Drewes ◽  
...  

1959 ◽  
Vol 81 (3) ◽  
pp. 187-199 ◽  
Author(s):  
E. J. Krabacher

Optimum utilization of grinding wheels can best be achieved if the nature of their performance and wear characteristics, and the factors that affect these characteristics, are understood and applied. As reported in this paper, a comprehensive, continuing, grinding-research program has contributed to such an understanding. A study of the nature of grinding-wheel wear indicates that the grinding-wheel wear curve is similar to those of other cutting tools. It demonstrates further that the type of grinding operation significantly affects the nature of wheel wear. A unique technique has been developed for very accurately measuring grinding-wheel wear. This measured wear may be translated into terms of “grinding ratio,” which is the generally accepted parameter for measuring wheel wear. It is the ratio of the volume of metal removed per unit volume of wheel worn away. Extensive studies have been carried out to determine the effect of mechanical variables on grinding ratio, power required in metal removal, and on surface finish. Experimental findings indicate that grinding ratio decreases with increased metal-removal rate and increases with workpiece diameter, decreased chip load, and increased concentration of grinding fluid. Power is found to increase with both the metal-removal rate and the amount of metal removed. It increases slightly with workpiece diameter and is affected little by work-material hardness. Surface finish is found to improve with decreased metal-removal rate and decreased chip load. It also is affected little by work diameter or work-material hardness. Fundamental research in the mechanics of wheel wear is supplying much additional information in the study of grinding-wheel wear. The measurement of grinding forces employing a cylindrical grinding dynamometer provides the opportunity for relating the wear of grinding wheels to the basic mechanics of the process through such fundamental quantities as grinding forces, specific energy, and grinding friction. Two additional experimental techniques for the study of chip formation in grinding have also proved to be most useful research tools. A “quick-stop” apparatus is used to freeze the grinding action by accelerating a tiny workpiece almost instantaneously to grinding-wheel speed. Another technique permits the comparison of the shape of the grinding grit and that of the contour of its path through the workpiece by a unique replicating method.


2003 ◽  
Vol 27 (3) ◽  
pp. 193-204 ◽  
Author(s):  
Andrew Warkentin ◽  
Robert Bauer

Grinding involves many randomly shaped and distributed abrasive grains removing material from a workpiece. Wheel wear results when these grains dull, fracture or break away. As a result, grinding forces are time-varying. In order to automate and optimize the grinding process an understanding of how forces are generated and change during grinding is critical to avoid workpiece damage, surface finish deterioration, cracking, excessive heat generation, and excessive residue stresses. This paper builds upon the existing grinding literature by studying the relationships between wheel wear and grinding forces for different depths of cut when surface grinding mild steel with an aluminum oxide wheel.


Author(s):  
M.A. Younis ◽  
H. Alawi

The high hardness and chemical effects of tool steels M2 and T15 cause a rapid grinding wheel wear and micro structural changes in the ground surface. The performance of sulphur-, wax-, and varnish-impregnated grinding wheels in grinding hardened tool steels M2 and T15 is investigated and compared with the performance of conventional alumina wheels. Impregnation with sulphur had in all cases beneficial effects by decreasing the grinding forces, increasing the maximum metal removal rate, improving surface integrity, and increasing considerably the grinding ratio. It also gave cost saving compared to the plain grinding wheel. The improvement was a result of the sulphur being more efficiently supplied into the chip formation process as compared to using grinding coolant only.


2017 ◽  
Vol 7 (1.1) ◽  
pp. 138 ◽  
Author(s):  
V. Jaiganesh ◽  
B. Yokesh Kumar ◽  
P. Sevvel ◽  
A.J. Balaji

In the present scenario of bulk manufacturing where Metal Removal Rate (MRR), Chip Thickness Ratio (CTR) and Surface Roughness (SR) is of significant importance in manufacturing the component using CNC (computer numerical controlled) machines. Nine experiments were conducted based on orthogonal array. General linear model has been generated for all the three output parameters such as (MRR, Chip Thickness Ratio surface roughness) versus input parameters (speed, time, depth of cut). The statistical method called the analysis of variance (ANOVA) is applied to find the critical factor. The Main effects of S/N ratio values are found and plotted in the form of graph. The optimized value is found for speed, time, and depth of cut by using “MINITAB” software. By using this optimized value the efficient metal cutting can be done in commercial mild steel.


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