Meister introduces Darmann X-Series open structure vitrified abrasive for bearing manufacturers

Meister explains that super-finishing, which is sometimes referred to as micromachining or short-stroke honing, is a low temperature, low stock removal process. It improves part geometry and surface finish by removing the amorphous layer formed during grinding. Removing relatively small amounts of material, surface finishes as fine as 0.012 micron Ra can be achieved leaving a tightly controlled cross-hatch pattern. This pattern is attained by the interaction of three interrelated motions. These are oscillation of the stone, or wheel rotation; rotary movement of the component; and pressure of the abrasive tool on the workpiece. Stones are used to finish cylindrical shapes. Fine grit cups and cylinder wheels are used to finish flat and spherical surfaces. In the super-finishing process, when the abrasive tool makes initial contact with the part, dull grains fracture or pull away from the matrix to produce a new cutting surface. As the tool 'self-dresses', relatively large amounts of stock will be removed from the workpiece. During the stock removal phase, abrasive grains begin to dull, while surface irregularities and geometry continue to improve. The induced porosity of X-Series takes the process capabilities a step further. Porosity is the ratio of space occupied by pores in a material matrix to its total volume. In vitrified bonded abrasive products it is also referred to as structure. A dense or closed structure features grains that are in tight proximity to one another, whereas an open structure has much larger voids between the grains. Open structure products tend to provide higher stock removal rates without clogging. Darmann X-Series vitrified abrasive, which has large pores evenly distributed throughout the tool, creates a very free cutting super-finishing abrasive tool with enhanced stock removal capability that is less likely to load or clog. This provides improved part quality and surface finish and an aesthetically appealing appearance, explains Meister. X-Series is available in a variety of abrasive types, including Alox and SiC, and grit sizes. Darmann produces a wide variety of conventional products used to super-finish a wide range of parts. The company has developed process technology capable of producing consistent, tightly graded stone products manufactured to precise geometries. Its superfine (finer than 320 grit) wheels and stones as used respectively in the medical and bearing industries.