Engineered Grinding Wheels - Precision grinding of optical glasses

精磨、粗粒、单层、金属结合剂金刚石砂轮，即工程砂轮，磨料粒突出高度均匀，磨粒平整，适用于光学眼镜的超精密磨削。在BK7和SF57玻璃上的实验表明，切割机制转变为韧性去除，可获得表面粗糙度约为Sa = 20 nm的光学表面。与常用的细粒度树脂结合金刚石砂轮相比，工程砂轮具有较高的耐磨性。因此，可以大大缩短周期性修整周期，实现大型光学工件超精密磨削的经济应用。因此，工程砂轮是一种经济和技术替代传统的细粒金刚石砂轮。然而，为了使工程砂轮在工业上得到应用，还需要进一步澄清一些基本问题。首先，了解光学玻璃亚表面区域的亚表面损伤的产生是一个主要的科学兴趣。此外，可能的宏观和微观磨损机制，这是由磨削过程引入的，但也由调理过程必须确定。分析磨砂玻璃的亚表面区，了解金刚石颗粒的磨损机理，是实现新型金刚石砂轮在大型玻璃表面磨削中的应用所必需的。

Defined dressed, coarse-grained, single layered, metal bonded diamond grinding wheels, so called Engineered Grinding Wheels, with uniform abrasive grain protrusion heights and flattened grains are suitable for ultra-precision grinding of optical glasses. Experiments on BK7 and SF57 glass show that the cutting mechanisms turn into ductile removal and optical surfaces with surface roughness of about Sa = 20 nm are achievable. Compared with usually used fine-grained, resin-bonded diamond grinding wheels Engineered Grinding Wheels exhibit a high wear resistance. Therefore periodically dressing cycles can be significantly reduced and an economical application of ultra-precision grinding of large optical workpieces is feasible. Thus, Engineered Grinding Wheels are an economic and technological alternative to conventional fine-grained diamond grinding wheels.To introduce Engineered Grinding Wheels in industrial application, however, further basic questions have to be clarified. First, knowledge about the generation of the sub-surface damages in the sub-surface zone of the optical glasses is one major scientific interest. Further, possible macro- and microscopic wear mechanisms of the diamond grains, which are introduced by the grinding process, but also by the conditioning process have to be identified. The analysis of the sub-surface zone of the ground glass and the understanding of the wear mechanisms of the diamond grains are essential in order to enable the application of these novel diamond wheels for grinding of large glass surfaces.