Surface Roughness

At present, industrial production is pursued maximum precision and quality of parts produced at proizvodstve.V consequence of this the tool that is used in metalworking to apply strict trebovaniya.Odnim of such requirements is the surface roughness of the tool. Treated grinding wheel surface has a different shape and microroughnesses vysoty.Mikronerovnostyami called protrusions and cavities with small distances (pitch) between them arising at the surface. Totality of the irregularities with respect to small steps that make up the surface relief, is microgeometry or roughness surface. As a result of abrasive grains on the surface of the tool is applied to the processed a huge number of mikrotsarapin forming Micro-lined. The surface roughness can be longitudinal and transverse with different directions of machining marks, which is determined by the trajectory of the relative movement of the abrasive tool. Transverse roughness is considered in a section perpendicular to the main motion the grinding wheel relative to the treated surface, and longitudinal roughness – in a parallel direction.

On the surface of the sharpened microroughnesses have a relatively small size (6 to 0.5 microns or less). The height of asperities and polished surfaces have been brought even less generally 0,80-0,05 microns. According to GOST 2789-73 set the surface roughness, which is determined by the numerical values of the parameters Ra and Rz in the normalized base lengths. Microroughnesses on the cutting edge, and the conditional radius of rounding appear after sharpening tool in the form of pitting and serrations. Chipping edges define a plane rear surface. Under jaggedness understand chipping the cutting edge of the front surface of the projection on the rear surface. When measuring the roughness of cutting edges on the tool instead of a diamond needle use special diamond spatula. The roughness of the front and rear surfaces of the cutting tool has a significant influence on the cutting process, the nature of chip removal, on the coefficient of friction between the front surface and strand, between the back and treated surfaces. In the manufacture of parts multiserial engineering (automotive parts, motozapchasti, spare parts for agricultural machinery, etc.) should be used qualitative metal cutting tools, having no large surface roughness.