Title: Ultra-precision machining of aluminium alloy surfaces for optical applications

Authors: Kui Liu, Hu Wu, Peiling Liu, Kah Chuan Shaw

Addresses: Singapore Institute of Manufacturing Technology, 71 Nanyang Drive, 638075, Singapore. ' Singapore Institute of Manufacturing Technology, 71 Nanyang Drive, 638075, Singapore. ' Singapore Institute of Manufacturing Technology, 71 Nanyang Drive, 638075, Singapore. ' Singapore Institute of Manufacturing Technology, 71 Nanyang Drive, 638075, Singapore

Abstract: Fabrication of optical quality freeform surfaces using ultra-precision machining technologies enables to achieve sub-micrometric form accuracy and nanometric surface finish. In this paper, ultra-precision machining of large aluminium alloy optical components has been conducted to investigate the machining performance and machined surface integrity. An ellipsoidal mirror surface and a lenticular lens array have been machined out using slow slide servo (SSS) turning, grooving and milling techniques with a single crystalline diamond tool on an ultra-precision machine centre. It was found that there are some striations on one segment of the machined ellipsoidal mirror surface. Through data density optimisation of angular increment dθ and arc length increment dc in C-axis positioning, the striation problem has been successfully solved, and surface roughness Ra of the machined ellipsoidal mirror surface has been achieved less than 10 nm. Work material microstructure and thermal stability of the machining centre significantly affected the machined lenticular lens surface quality. Compared with grooving process, milling process could produce a better surface integrity and form accuracy of large aluminium lenticular lens array.

Keywords: ultra-precision machining; mirror surfaces; optical components; diamond tooling; freeform surfaces; nanometric surface finish; nanotechnology, nanomanufacturing; aluminium alloys; surface integrity; machining performance; lenticular lens; turning; grooving; milling; striations; microstructure; thermal stability; surface quality.

DOI: 10.1504/IJNM.2011.040718

International Journal of Nanomanufacturing, 2011 Vol.7 No.2, pp.116 - 125

Received: 19 Oct 2010
Accepted: 19 Jan 2011
Published online: 28 Feb 2015 *

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