Research On Manufacturing And Performance Of Monolayer Brazed And Orderly Arrayed CBN Grinding Wheels

With the development of modern machining in the direction of high speed, high efficiency、high precision high automation and low cost, as well as some new difficult-to-machine materials, SiC、Traditional grinding tools cannot completely meet the current requirement for grinding. There are several distinguished properties for Cubic boron nitride (CBN) abrasive, such as extremely high hardness, superior thermal stability, large chemical inertia and excellent thermal conductivity. CBN wheels have been utilized widely in grinding difficult-to-machine materials. Monolayer brazed and orderly arraged CBN grinding wheels were manufactured, and were used in gringding hardend45steel, the Brazing mechanism of CBN grits and effect of CBN grits arrangement form on the performance of CBN grinding wheels were investigated.Through experiment of brazing CBN grits, the parameters of brazing CBN grits and the mechanism of brazing CBN grits was studied. Four parameters for orderly arrangement of CBN grits were setted, including horizontal spacing(△X), vertical spacing(△Z), alignment Angle(α) and dislocation spacing (△ZV). Depending on those parameters, monolayer brazed CBN grinding wheels were made with different forms of ordered arrangement of CBN grits, and were applied to grinding hardened steel. The effect of the abrasive orderly arrangement form of single-layer brazing CBN grinding wheel on grinding force, grinding temperature, surface roughness of workpiece, surface topography of workpiece and chip morphology, wear form and process of CBN grinding wheel were studied.The results following were obtained.In the process of brazing CBN grits, the active Ti element gathered to the surface of the CBN grits obviously, and on the surface of the CBN grits generated TiN, TiB and TiB2.The surface roughness is increased with the increase of vertical spacing while the influence of horizontal spacing on the surface roughness is small, when the arrangement density of CBN grits is increased, the grinding forces and grinding temperature will increase.With the increasing of the number of abrasive mesh, decrease of the particle size, surface roughness,grinding force and grinding temperature also present decreasing trend. When the arrangement angle is50°, surface roughness of workpiece, grinding force and grinding temperature is lower than30°，70°and90°.With the increase of wheel speed, grinding force and surface roughness decrease, the grinding temperature increase; With the increase of grinding depth, grinding force, grinding temperature and surface roughness are increasing gradually.Grinding groove spacing and width of chip are increased with the increase of vertical spacing of CBN grits. The chip length increases with the increase of horizontal spacing of CBN grits. The chip size increases with the increase of abrasive particle size.Wear process of monolayer brazed and orderly arrayed CBN grinding wheels is Complete,micro broken, wear small platform, macro broken,fall off. During the process of grinding, grinding force ratio gradually increased.