Linear Grinding of Microbores Using Diamond-Adhered Wire

Abstract

Use of microbores of size φ = 100 µm or less has become increasingly common for engineering components especially for microfluidics, optical communications and precision engineering applications. These microbores demand nanometric surface finishes to achieve lower insertion loss (<25 dB) for optical applications, ripple-free flow in microfluids and enhanced assembly accuracies in precision engineering. To meet such stringent requirements, microbores are currently produced using microabrasive slurry polishing. Since, this method introduces severe clogging of abrasive particles and requires frequent cleaning, a linear diamond wire grinding method was devised to process microbores up to φ = 80 µm. Prior to microbore polishing, the microbores were formed through a sintering process, and the interacting surfaces were treated as convex–concave which determines the conditions of the contact mechanics. This article explains both theoretical and experimental components of linear diamond wire grinding and outlines the design of a new microbore polishing machine. The process monitoring and signal processing techniques for measuring the cutting forces, wire speed, down feed rate, and wire bow angle in diamond wire linear grinding are also discussed.

Keywords:

• Diamond
• Ferrule
• Linear grinding
• Microbore
• Micromachine
• Micromachining
• Miniature
• Nanometric surface finish
• Polishing

ACKNOWLEDGMENTS

The authors would like to thank Drs. Lee Loke Chong and Liu Xiang Dong, of SIMTech Singapore, Mr. Peter of Norelco Centreline Pte Ltd, Singapore and Prof. C K Sankat, Dean-Faculty of Engineering, The University of the West Indies for their active discussion and encouragement during the development of the microbore polishing machine and preparation of this manuscript.