Title: Analysis of entry and exit delamination during micro-drilling of green composites using response surface methodology

Authors: Mridusmita Roy Choudhury; Hrishikesh Dutta; Kishore Debnath

Addresses: Department of Mechanical Engineering, National Institute of Technology Meghalaya, Shillong – 793 003, India ' Department of Mechanical Engineering, National Institute of Technology Meghalaya, Shillong – 793 003, India ' Department of Mechanical Engineering, National Institute of Technology Meghalaya, Shillong – 793 003, India

Abstract: Micro-drilling of fibre-reinforced composites is an inevitable machining operation in the different sectors namely biomedical, aerospace, and automobile, to name a few. However, the damages induced during micro-drilling of fibre-reinforced composites due to the anisotropic and heterogeneous nature of the composite is an observable impediment. Thus, in this research endeavour, the micro-drilling behaviour of green composite composed of bamboo fibre and poly(lactic) acid (PLA) was experimentally investigated. The intrinsic effect of the process parameters namely drill diameter (300, 400, and 500 μm), feed (1, 1.5, and 2 mm/min), and tool speed (300, 400, and 500 RPM) on the induced delamination both at the entry and exit side of the hole was studied by performing response surface methodology (RSM). The drill diameter was found to be the most significant parameter affecting the induced delamination. Delamination was found to be increased with the drill diameter and decreased with the tool speed. The lower level of drill diameter (300 μm), higher level of feed (2 mm/min), and higher level of tool speed (500 RPM) was found to be the optimised parametric setting to obtain the lower value of delamination factor. The optimised delamination factors at the entry and exit sides of the hole were found to be 1.318 and 1.359.

Keywords: micro-drilling; green composite; delamination; response surface methodology; RSM.

DOI: 10.1504/IJPTECH.2020.112047

International Journal of Precision Technology, 2020 Vol.9 No.2/3, pp.175 - 190

Received: 29 Jan 2020
Accepted: 25 Jun 2020
Published online: 23 Dec 2020 *

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