This study was performed to evaluate the grinding performance from the mechanical properties of the grain layer of a superabrasive grinding wheel. The critical grain holding power was shown to change according to the kinds of filler in the grain layer of a resinoid bond diamond wheel. In addition, the amount of change in abrasive grain protrusion height in the grinding process and the characteristics of the truing were shown to change according to the kinds of filler. Moreover, the Young's modulus and the bending strength of the grain layer of a resinoid bond diamond wheel were measured by three-point bending test and the ultrasonic pulse method. The mechanical properties, such as bending strength and Young's modulus, were shown to change according to the kinds of filler. The modulus of rupture was calculated from the Young's modulus and the bending strength. The results indicated a good correlation between the modulus of rupture and the critical grain holding power. That is, the critical grain holding power of a resinoid bond diamond wheel can be evaluated from the modulus of rupture. It may be possible to predict the grinding performance from the modulus of rupture of the grain layer of a resinoid bond diamond wheel.

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The process of traverse dressing using a prismatic diamond rotary dresser was simulated based on a kinematic model, and the effects of dressing conditions on the grinding wheel removal per diamond grit, the actual depth of cut of diamond grit in dressing, and on the rubbed area of the grinding wheel surface in dressing-out were investigated. The prismatic diamond grit of the rotary dresser cuts the grinding wheel surface intermittently so that a residual depth of cut remains on the dressed surface, resulting in grinding wheel removal and an actual depth of cut that are larger than those calculated geometrically on the assumption that the dressed surface is flat. The actual depth of cut of diamond grit for down-cut dressing is greater than that for up-cut dressing when the depth of cut of dresser and the velocity ratio have the same values. The ratio of the rubbed area increases with the circumferential length of the diamond grit and is affected by neither the depth of cut of the dresser nor the velocity ratio.

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Rolling-element bearings are mostly composed of SUJ2 steel due to its high wear and fatigue resistance. Rolling-element bearings are machined by cermet tools because cermets have low affinity with iron-based materials, and are processed with high efficiency and high precision by plunge cutting. However, this plunge cutting process has a large contact surface product between the cutting tool edge and the work material, and so thermal cracks occur on the cutting tool edge because of simultaneous loading of mechanical stress and thermal shock. In this study, the effects of the type and quantity of carbide added, the amount of metal binder phase, and sintering temperature on the heat cracking resistance of TiCN-based cermet were investigated at room temperature from the viewpoint of differences in number of heat cracks in the tool cutting edge and microstructures of carbonitride phases in plunge cutting of SUJ2 steel. The longest values of tool life of cermets were obtained in the case where NbC content was 5 vol% and the metal binder phase was 10 vol%, and TaC-containing cermets showed generally longer tool life than NbC-containing cermets. Furthermore, it was shown that the tool life of TiCN-based cermet was related to solid solution strength of the metal binder phase and development grade of the CORE-RIM structure of cabonitride phase.

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