High Aspect Ratio Micro-EDM Drilling with Nano Surface Finish
This paper presents the issues related to high aspect ratio in micro drilling on metallic materials using micro electro discharge machining (Micro-EDM). Experimental investigation is carried out by drilling high aspect ratio micro holes on copper workpiece with 1 mm diameter tungsten carbide tool electrode using micro-EDM DT 110 with two varying parameters voltage and capacitance. For the measurement and observation of aspect ratio, roundness, and surface roughness were performed by scanning electron microscope, optical microscope, and WYKO NT1100 optical profiler respectively. The purpose of this paper is to achieve high aspect ratio, accurate roundness, and low surface roughness with the minimum wear of tool electrode within machining time. The data were analyzed by Design Expert software. Emperical models for aspect ratio, roundness, and surface roughness are developed. The analysis revealed that the most influential parameter is capacitance. Multiple optimization of responses showed that the optimum parameter values are 90 V gap voltage and 0.26 µF capacitance which provide 2.4 aspect ratio, 44 µm roundness, and 6.0 µm Ra surface roughness. The desirability achieved by optimization is 73.9%. The models are validated by experiments.
KeywordsHigh aspect ratio Micro-EDM Micro-hole Nano surface finish Roundness
This research was conducted under the Science Fund grant 03-01-08-SF0135 and Fundamental Research Grant Scheme FRGS12-074-0223 from Ministry of Science and Technology and Ministry of Education of Malaysia. The authors are grateful to the micromanufacturing laboratory where the experimental studies were conducted.
- Azlan AR, Azuddin M, Wagiman A (2009) Effect of machining parameters on hole quality of micro drilling for brass. J Mod Appl Sci 3(5):27–30Google Scholar
- Billa S, Sundaram MM, Rajukar KP (2010) A study on the high aspect ratio micro hole drilling using ultrasonic assisted micro electro discharge machining. In: Proceedings of the ASPE 2007 Spring Topical Meeting, vol 40, pp 32–36Google Scholar