Wheel hardness and local elastic deflections in grinding

Abstract

The local contact deflections caused by the elastic behavior of the wheel and work-piece are important factors affecting the mechanism of metal removal and the precision of manufactured parts. In spite of the extensive research directed in this area, there is however much use in industry of the rules of thumb or spark out techniques in finish grinding operations to produce components with good surface finish and close dimensional tolerances. These operations can be time consuming and reduce equipment productivity, particularly when the recent trend is towards higher productivity through automation such as adaptive control of processes. It is therefore very essential not only to fully understand the nature and mechanism of the local contact deflections but also the influence of parameters which affect them. This paper considers the use of two techniques for the study of local contact deflections. The single grain cutting technique which employed a single cutting grain on a dressed but otherwise complete wheel, rather than a single grain attached to a disc, was observed to be not suitable for studying the effect of wheel grade on contract deflections. Contrary to the several previous observations the deflections were observed to decrease with the increase in wheel hardness. The influence of the proximity of a clump of grains on the local contact deflections of a single grain was also examined.