Abstract An investigation was made into the effect of grit size and dressing conditions on specific energy, surface-finish characteristics and wheel wear, with a focus on whether smaller, sharp-dressed grits and larger, dull-dressed grits produce different specific energies and surface-finish distributions, even for the same Ra surface-roughness. Grinding tests were performed and measurements were made of grinding forces, wheel wear, Ra, Rt and surface-height distributions. Observations were made of SEM photos of ground surfaces. Results show that, for a given Ra surface roughness, smaller, sharp-dressed Al2O3 grits give significantly lower specific energies and slightly lower Rt values than larger, dull-dressed grits over a large range of grit sizes. This has significant implications in terms of thermal-damage risk and cycle times. Also, using larger, dull-dressed CBN grits requires too-frequent dressing in order to maintain surface roughness. A new concept is developed, the nominal bond shear stress, which can be used to quantify the risk of grit fracture or bond fracture in a single grit. The fundamental relationships between grit size, grit sharpness and contact mechanisms are discussed and practical recommendations are given.

中文翻译：

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大而钝或小而锋利：使用 Al2O3 和 CBN 进行磨削以达到给定的表面粗糙度时的比能、砂轮磨损、表面生成机制和表面特性的比较

摘要 研究了磨粒尺寸和修整条件对比能、表面光洁度和砂轮磨损的影响，重点研究了较小的、修整过的磨粒和较大的、无光泽的磨粒是否会产生不同的比能和表面。 -完成分布，即使对于相同的 Ra 表面粗糙度。进行了磨削测试并测量了磨削力、砂轮磨损、Ra、Rt 和表面高度分布。对地表的 SEM 照片进行了观察。结果表明，对于给定的 Ra 表面粗糙度，在较大的磨粒尺寸范围内，较小的、修整过的 Al2O3 磨粒比较大的、无光泽修整的磨粒提供显着较低的比能和略低的 Rt 值。这在热损坏风险和循环时间方面具有重要意义。还，使用较大的、无光泽的 CBN 磨粒需要过于频繁的修整以保持表面粗糙度。开发了一个新概念，即标称结合剪切应力，可用于量化单个磨粒中磨粒断裂或结合断裂的风险。讨论了磨粒尺寸、磨粒锐度和接触机制之间的基本关系，并给出了实用的建议。