Effect of Thermal and Material Anisotropy of Pyrolytic Carbon in Vibration-Assisted Micro-EDM Process. Issue 14 (25th October 2016)

• Record Type: Journal Article
• Authors: Bajpai, Vivek; Mahambare, Pratik; Singh, Ramesh K.
• Is Part Of: Materials and manufacturing processes. Volume 31:Issue 14(2016)
• Page Start: 1879
• Page End: 1888
• Publication Date: 2016-10-25
• Subjects: Electrode discharge machining -- Microfeatures -- Micromachining -- Pyrolytic graphite; Manufacturing processes -- Periodicals; Materials -- Periodicals; Manufactured Materials; 670.5
• DOI: 10.1080/10426914.2015.1127937
• Languages: English
• ISSNs: 1042-6914

Abstract

Abstract : Pyrolytic carbon (PyC) is extremely biocompatible with high directional strength and unique directional thermal conductivity. PyC is used in biomedical devices like cardiovascular implants and finger prosthesis. Microfeatures on PyC have been proven as performance-driving agents in many cases. This work is focused on micro-electric discharge machining (micro-EDM) characterization of PyC to understand the effect of material/thermal anisotropy on the process response. An L9 Taguchi design of experiments has been performed to analyze the effect of gap voltage, capacitance, and frequency on the MRR, surface quality, and dimensional accuracy. MRR increases by 16% with vibration in AB plane machining. In C plane, the effect of vibration on MRR is not favorable. MRR reduces by 56% if the machining plane changes from AB to C due to the lower thermal conductivity along C. Surface roughness decreases by an order of magnitude if machining plane changes from AB to C; surface roughness of 65 nm has been achieved in C plane under certain conditions. The error in dimensional accuracy in C plane is 46% lower than AB plane. EDS shows noncontaminated machined surface. Finally, micro-EDM process has been used to create microfeatures in PyC, which could potentially improve/alter the desired surface quality.