Advances in the interrupted surface manufacturing by applying different lubri-refrigeration techniques in the grinding process

Abstract

The grinding of interrupted geometries presents technical difficulties such as mechanical impacts and higher thermal gradients regarding the continuous process, resulting in decreased workpiece quality, premature tool wear, and increased costs. However, few studies about interrupted grinding are available. In this context, the present research evaluates the plunge cylindrical grinding of workpieces with different geometries (0, 2, 6, and 12 grooves), made of AISI 4340 quenched and tempered steel, using a CBN grinding wheel, conventional and converging nozzle in lubri-refrigeration, and three feed rates (0.25, 0.50, and 0.75 mm/min). The output parameters analyzed were surface roughness, roundness deviation, diametrical wheel wear, G-ratio, grinding power, metallographic analysis, and cost of the grinding wheel. The converging jet lubri-refrigeration method presented better performance than the conventional one in all tested conditions, reducing by up to 25% the surface roughness, 20% the roundness deviation, 11% the diametrical wheel wear, 11% the grinding power, and 23% the grinding wheel cost.