Improvement of precision grinding performance of CVD diamond wheels by micro-structured surfaces
Improvement of precision grinding performance of CVD diamond wheels by micro-structured surfaces
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DOI：
10.1016/j.ceramint.2018.06.197
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发表时间：
2018-10
影响因子：
5.2
通讯作者：
B. Guo;Mingtao Wu;Qingliang Zhao;Han Liu;Jun Zhang
中科院分区：
文献类型：
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作者：
B. Guo;Mingtao Wu;Qingliang Zhao;Han Liu;Jun Zhang
化学气相沉积（CVD）金刚石砂轮因其颗粒密度高、磨料分散均匀、耐磨性好等优点，被广泛应用于精密和超精密磨削。然而，CVD金刚石磨料表面的小切屑空间容易中断磨削，这限制了这些砂轮的实际应用。为了提高光学玻璃的磨削性能，提出了一种新型微结构CVD金刚石砂轮。首先，利用脉冲激光在CVD金刚石表面烧蚀宽度为4-6 µm、深度为8 µm的连续且清晰的微凹槽。与传统结构砂轮不同，CVD金刚石的晶粒尺寸由10 ~ 20 µm细化到5 ~ 15 µm。其次，研究了光学玻璃的微结构对磨削力、磨削力比和磨削质量的影响。法向力减小了48-65%，切向力减小了25-54%。由于磨粒边缘的增加和大多数晶粒前倾角的变化，法向磨削比明显降低。测量结果表明，表面粗糙度降低了5-20%，亚表面损伤深度降低了约25%。此外，磨损形貌表明，CVD金刚石晶粒尖端和微凹槽边缘均出现磨平现象。这表明微观组织有效地参与了磨削过程，从而导致晶粒密度的增加和切削力的增强。
Chemical vapor deposition (CVD) diamond grinding wheels are used in precision and ultra-precision grinding owing to the high grain density, uniform dispersion of abrasives, and excellent wear resistance. However, the small chip space on the CVD diamond abrasive surface easily interrupts the grinding, which limits the practical applications of these wheels. In this paper, a novel micro-structured CVD diamond wheel was presented for precision grinding of optical glass, to improve the grinding performance. First, continuous and clear micro grooves of 4–6 µm width and 8 µm depth were ablated on the surface of a CVD diamond by a pulsed laser. Different from the conventional structured wheels, the grain size of the CVD diamond was refined from 10 to 20 µm to 5–15 µm by laser micro-structuring. Second, the effect of the micro-structures on the grinding force, force ratio, and ground quality were investigated for optical glass. The normal forces decreased by 48–65%, whereas the tangential force dropped by 25–54%. The normal-to-tangential grinding ratio also clearly reduced owing to the increasing abrasive edges and change in the rake angle of most grains. The measurement results of the ground surface showed that roughnessRadecreased by 5–20% and subsurface damage depth reduced by approximately 25%. In addition, the wear morphology exhibited that abrasion flattening occurred not only on the CVD diamond grain tips but also on the side edges of the micro grooves. This implied that the micro-structures effectively participated in the grinding process, and thus, resulted in an increase in the grain density and enhancement of the cutting effort.