Deformation analysis of micro/nano indentation and diamond grinding on optical glasses
Deformation analysis of micro/nano indentation and diamond grinding on optical glasses
复制标题
DOI：
10.3901/cjme.2012.03.411
复制
发表时间：
2012-04
影响因子：
4.2
通讯作者：
Qingliang Zhao;Lingling Zhao;B. Guo;David Stephensin;J. Corbett
中科院分区：
文献类型：
--
作者：
Qingliang Zhao;Lingling Zhao;B. Guo;David Stephensin;J. Corbett
以往对光学玻璃精密磨削过程中电解在线修整（ELID）技术的研究主要集中在ELID和加工参数的作用上，其目的是获得非常“光滑”的表面，减少亚表面损伤。然而，在ELID技术辅助下磨削spectrosil 2000和BK 7玻璃时，对材料去除机理和砂轮磨损行为的对比研究还很少。本文首次将微纳压痕技术应用于光学玻璃的力学性能研究，并将其结果作为评价光学玻璃可加工性的参考。单磨粒金刚石在玻璃上的划痕，根据材料去除方式的不同，划痕呈现出四种不同的划痕特征。在常规磨削实验中，BK7玻璃的可加工性优于spectrosil 2000玻璃，与微纳米压痕试验结果相吻合。在磨削深度参数相同的情况下，声发射原始信号幅值、磨削力和磨削力比越小，表面质量越好。而对于这两种玻璃，随着磨削深度的增加，表面粗糙度、力比和声发射原始信号的变化趋势相反，这应归因于不同的材料去除模式。砂轮表面的扫描电镜观察表明，磨削BK7玻璃后，砂轮表面的金刚石磨粒磨损较spectrosil 2000严重。该研究分析了不同材料去除方式下的磨削过程，为生产高质量光学玻璃提供依据，并对光学玻璃的表面和亚表面完整性进行综合评价。
The previous research of precision grinding optical glasses with electrolytic in process dressing (ELID) technology mainly concentrated on the action of ELID and machining parameters when grinding, which aim at generating very “smoothed” surfaces and reducing the subsurface damage. However, when grinding spectrosil 2000 and BK7 glass assisted with ELID technology, a deeply comparative study on material removal mechanism and the wheel wear behaviors have not been given yet. In this paper, the micro/nano indentation technique is initially applied for investigating the mechanical properties of optical glasses, whose results are then refereed to evaluate the machinability. In single grit diamond scratching on glasses, the scratching traces display four kinds of scratch characteristics according to different material removal modes. In normal grinding experiments, the result shows BK7 glass has a better machinability than that of spectrosil 2000, corresponding to what the micro/nano indentation vent revealed. Under the same grinding depth parameters, the smaller amplitude of acoustic emission (AE) raw signals, grinding force and grinding force ratio correspond to a better surface quality. While for these two kinds of glasses, with the increasing of grinding depth, the variation trends of the surface roughness, the force ratio, and the AE raw signals are contrary, which should be attributed to different material removal modes. Moreover, the SEM micrographs of used wheels surface indicate that diamond grains on the wheel surface after grinding BK7 glass are worn more severely than that of spectrosil 2000. The proposed research analyzes what happened in the grinding process with different material removal patterns, which can provide a basis for producing high-quality optical glasses and comprehensively evaluate the surface and subsurface integrity of optical glasses.