Fractal Analysis of Grain Cutting Edge Wear in Superabrasive Grinding
This paper deals with a fractal analysis of the wear behavior of the grain cutting edges in superabrasive grinding. Fundamental overcut fly grinding experiments for producing individual straight grooves using a grinding tool with multiple grits are carried out to clarify the wear characteristics of the grain cutting edges in the grinding process and then the change in three-dimensional profile of the cutting edge measured with a multiprobe SEM is evaluated on the basis of fractal analysis. The main results are summarized as follows: (1) Fractal dimension for the contour line of the fine cutting edge formed by micro fracture shows a higher value than that of cutting edge formed by attritious wear or large fracture. (2) Fractal dimension for cBN grain cutting edge mainly formed by micro fracture tends to take a higher value than that for diamond grain cutting edge mainly formed by attritious wear. (3) The complex change in shape of the cutting edge with the progress of grinding process can be quantitatively evaluated by means of fractal analysis.
Innovations in Abrasive Products for Precision Grinding
Abstract This paper is a review of recent developments in the design and manufacture of precision, fixed-abrasive tools. The role of each component within the “engineered composite” is also discussed, with examples showing how the components have been enhanced to achieve their current high levels of performance. The paper also looks at examples where innovations in the abrasive tool have enabled the development of innovative abrasive processes. A vision of future abrasive product developments is also presented by the authors.
Mechanisms of Material Removal in the Precision Production Grinding of Ceramics
Grinding of ceramics is often treated as coarse grinding dominated by brittle fracture or fine grinding, at very low removal rates, dominated by plastic deformation. Through a set of experimental observations and analysis, it is shown that in grinding of ceramics the abrasive/work interaction can be treated similar to well known chip formation models. Such an approach permits the coexistence of ductile deformation and brittle fracture during the grinding of ceramics. When the grinding process is managed such that the brittle fracture is minimized, while maximizing the plastic deformation optimum results are achieved. In this regard it is conceivable to design ceramic grinding cycles, where the rough grinding cycle focuses on surface generation to achieve high material removal rate and productivity while minimizing brittle fracture and the finish grinding cycle focuses on surface generation which maximizes plastic deformation while still minimizing brittle fracture. While the above accounts for only one offour interactions in the grinding zone (viz) abrasive/work interaction, it is also necessary to address the other three interactions (viz) chip/bond, chip/ work and bond/work interactions. The later considerations for ceramics grinding are identical to well established practices in metal grinding. When such grinding cycle optimization is carried out taking simultaneously into account the aspects of machine tool, grinding wheel, work material and operational factors, significant progress can be made in the grinding of ceramics. The results obtained through such systems approach are also described in this paper.