Sharpening of graded diamond grinding wheels

Abstract

Grinding the flutes of cemented carbide end mill cutters results in high and uneven radial wear of the grinding wheel. This is a consequence of the varying geometrical contact conditions over the grinding wheel width. Decreased manufacturing accuracy regarding the tool target geometry is the consequence. To compensate for this, the dressing intervals must be shortened. High non-productive times and an additionally reduction of the grinding layer results from this. The higher non-productive times reduce the productivity of the grinding process and, in conjunction with the shorter lifetime of the grinding tool, thus increase the costs per work piece. It has already been shown that load-adapted grinding wheels can reduce uneven radial wear up to 50%. The adaptation of the wear behaviour to non-uniform engagement conditions causes non-uniform radial wear to occur again under uniform engagement conditions. Uniform engagement conditions occur during grinding wheel sharpening. Therefore, the present study investigates the influence of sharpening on the grinding tool topography. For this purpose, sharpening tests are carried out on four differently graded grinding wheels. For comparability, the tests are also carried out on two non-graded grinding wheels. In the present work, the surface parameters are evaluated with regard to their suitability for analysing the sharpening condition of graded grinding wheels. The grain protrusion derived from this is subsequently used for evaluation. For this, a dependency on the grain concentration is proven and the grain protrusions are shown over the grinding wheel widths. From this, sharpening parameters are determined that enable reproducible sharpening of graded grinding wheels.