Abstract Gallium gadolinium garnet (GGG) single crystals are the primary host material for making the high-power solid-state lasers. GGG single crystals are difficult-to-machine materials due to their high hardness and brittleness. Ultra-precision grinding experiments of GGG crystals was carried out, which generated the ground surface and subsurface free of brittle fracture and cracks. The TEM examination demonstrated that the plastic formation of GGG crystals induced by ultra-precision grinding was dominated by the slippage of (114) crystal planes, as well as nanocrystallization and amorphization. Morphology and roughness of the ground surfaces were measured by AFM. A theoretical model was developed for predicting the surface morphologies and surface roughness by considering the random distributions of the radius, location and protrusion height of abrasive grits. The simulated results were found to be in good agreement with the experiment. This model is thus useful for understanding the effect of material deformation and removal on the surface finish in ultra-precision grinding of hard and brittle crystals, and can provide meaningful guidance for optimizing the process parameters of grinding of hard and brittle crystals.

中文翻译：

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GGG单晶无裂纹磨削变形特性及表面生成建模

摘要 镓钆石榴石（GGG）单晶是制造高功率固体激光器的主要基质材料。GGG单晶硬度高、脆性大，是难加工材料。对GGG晶体进行超精密磨削实验，磨削表面和亚表面无脆性断裂和裂纹。TEM 测试表明，超精密研磨诱导的 GGG 晶体的塑性形成主要是（114）晶面的滑移以及纳米化和非晶化。通过原子力显微镜测量地表的形态和粗糙度。通过考虑半径的随机分布，开发了用于预测表面形貌和表面粗糙度的理论模型，磨粒的位置和突出高度。发现模拟结果与实验非常吻合。因此，该模型有助于理解硬脆晶体超精密磨削中材料变形和去除对表面光洁度的影响，并可以为优化硬脆晶体磨削工艺参数提供有意义的指导。