No abstract

No abstract

The spatial distribution of sharp cutting edges around the active periphery of a grinding wheel has an important effect on the surface finish of ground components. In addition, random protrusion of sharp edges can result in a random distribution of grinding forces acting on the ground surface. A uniformly dressed and accurately trued wheel is essential for successful grinding. Since these conditions will alter during use, monitoring of them during grinding must be a requirement for critical grinding operations. This paper describes a new system for achieving on-line detection of the grinding wheel condition. The system uses a small air flapper nozzle-transducer arrangement which detects in-process changes of the grinding wheel surface topography, where external triggering of the data-acquisition system ensures a highly accurate identification of the wheel's surface topography irrespective of wheel speed. The benefits of this system are illustrated by experimental results that correlate the measurement of wheel topography by two means: flapper nozzle and stylus.

Contact area deformation between grinding wheel and workpiece is one of the major parameters that affect the susceptibility of the grinding process to chatter. Introducing an artificial damping to this area is one way to improve the process stability. Damping can be introduced by creating a high hydrodynamic pressure in the contact zone wedge between the wheel and the workpiece. Using high viscosity coolant with an impervious grinding wheel such as a diamond grit wheel will produce this pressure. This paper presents a theoretical and experimental model which confirms the favourable effect of the induced hydrodynamic pressure on the stability and hence the chatter that may be present in the grinding process.

Diamond grinding of ceramics creates an interaction of complex elastic/plastic deformations within the ceramic workpiece. These deformations cause cracking on the surface and in the bulk of the ceramic, where cracks of different types, locations and characteristics can be produced. During grinding, cracks may propagate, open or close. This paper describes the production of cracks during the grinding of silicon nitride. Radial, median and lateral cracks are identified and the type of crack produced is linked to grinding parameters such as grit size, bond type, depth of cut, feed rate, etc.