Theoretical and Experimental Investigation of Surface Topography Generation in Slow Tool Servo Ultra-Precision Machining of Freeform Surfaces

Materials

Duo Li¹  Bo Wang¹  Yutao Liu¹  Zheng Qiao¹  Jiadai Xue¹  Karl Walton²  Xiangqian Jiang² 

[1] Centre for Precision Engineering, Harbin Institute of Technology, Harbin 150006, China;EPSRC Future Metrology Hub, University of Huddersfield, HD1 3DH Huddersfield, UK;

关键词: ultra-precision machining;    slow tool servo;    surface topography;    simulation;    microlens array;    sinusoidal grid;   

DOI  :  10.3390/ma11122566

来源: DOAJ

【 摘 要 】

Freeform surfaces are featured with superior optical and physical properties and are widely adopted in advanced optical systems. Slow tool servo (STS) ultra-precision machining is an enabling manufacturing technology for fabrication of non-rotationally symmetric surfaces. This work presents a theoretical and experimental study of surface topography generation in STS machining of freeform surfaces. To achieve the nanometric surface topography, a systematic approach for tool path generation was investigated, including tool path planning, tool geometry selection, and tool radius compensation. The tool radius compensation is performed only in one direction to ensure no high frequency motion is imposed on the non-dynamic axis. The development of the surface generation simulation allows the prediction of the surface topography under various tool and machining variables. Furthermore, it provides an important means for better understanding the surface generation mechanism without the need for costly trial and error tests. Machining and measurement experiments of a sinusoidal grid and microlens array sample validated the proposed tool path generation and demonstrated the effectiveness of the STS machining process to fabricate freeform surfaces with nanometric topography. The measurement results also show a uniform topography distribution over the entire surface and agree well with the simulated results.

【 授权许可】

Unknown