Ultra-precision grinding of Gd3Ga5O12 crystals with graphene oxide coolant: Material deformation mechanism and performance evaluation
Ultra-precision grinding of Gd3Ga5O12 crystals with graphene oxide coolant: Material deformation mechanism and performance evaluation
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DOI：
10.1016/j.jmapro.2020.11.037
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发表时间：
2021-01-01
影响因子：
6.2
通讯作者：
Zhang, Feihu
中科院分区：
文献类型：
--
作者：
Li, Chen;Li, Xuliang;Zhang, Feihu
稀土氧化物激光晶体是制造大功率固体激光器的主要基质材料。然而，由于晶体的高硬度和脆性，在研磨加工过程中容易在其表面和亚表面形成脆性断裂和裂纹，严重降低激光器的输出功率。本文通过将GO纳米片分散在水中制备了一种磨削液，并对GGG激光晶体进行了系统的磨削实验。通过拉曼光谱和截面透射电镜检测技术，在原子尺度上揭示了GO辅助研磨诱导GGG晶体塑性变形的机制。结果表明，GO助磨过程中GGG晶体的塑性变形受GO的层间滑移和填充作用的影响，并以晶面滑移引起的多晶纳米晶和非晶转变为主。与常规磨削相比，GO冷却剂的使用能够显著降低磨料-基底界面处的摩擦，这是由于它们的自润滑效应，从而导致改善的磨削表面质量。该工作将为激光晶体的高效、低损伤超精密磨削提供新的理论依据和技术支持。
Laser crystals of rare-earth oxide are primary host materials for making solid-state lasers of large power. However, brittle fractures and cracks are easily formed on the crystal's surface and subsurface during abrasive machining process owing to their high hardness and brittleness, which will seriously reduce output power of the lasers. In this work, a grinding coolant was synthesized through dispersing GO nanosheets in water, and the grinding experiment of GGG laser crystals assisted by GO coolant lubrication was systematically performed. The plastic deformation mechanism of GGG crystals induced by GO assisted grinding was revealed at close-to-atomic scale by Raman spectrum and cross-section TEM detection technologies. The results indicated that the plastic deformation of GGG crystals during GO assisted grinding was affected by the interlayer slip and filling actions of GO, and was dominated by polycrystallization nanocrystals and amorphous transformation caused by the crystal plane slipping. The use of the GO coolant enabled to lower friction at the abrasive-substrate interface significantly owing to their self-lubricating effect, thus resulting in improved ground surface quality, in comparison with conventional grinding. This work will provide a new theoretical basis and technical support for high-efficiency and low-damage ultra-precision grinding of laser crystals.