Title: Prediction of material removal rate due to laser beam percussion drilling in aluminium sheet using the finite element method
Authors: Sanjay Mishra; Vinod Yadava
Addresses: Mechanical Engineering Department, Motilal Nehru National Institute of Technology, Allahabad-211004, Uttar Pradesh, India ' Mechanical Engineering Department, Motilal Nehru National Institute of Technology, Allahabad-211004, Uttar Pradesh, India
Abstract: Laser beam percussion drilling is used for the rapid fabrication of small diameter hole in a wide variety of engineering materials. A computational thermal model to predict the material removal rate will help to enhance the cost effectiveness of LBPD process especially for material like aluminium which has very low machinability during laser beam machining due to its adverse optical and thermal properties. An axisymmetric finite element method-based thermal model incorporating the temperature dependent thermal and optical properties as well as the phase change phenomena has been developed to determine the transient temperature distribution in thin aluminium sheet, which is further used to obtain the material removal rate (MRR). The predicted values of MRR have been compared with the self conducted experimental results. It was found that the peak power has the dominant effect on MRR followed by thickness of sheet, pulse width and pulse frequency.
Keywords: laser beam percussion drilling; LBPD; axisymmetric FEM; finite element method; thermal modelling; material removal rate; MRR; phase change; machinability; absorption coefficient; Nd:YAG lasers; sheet thickness; small diameter holes; aluminium sheet; peak power; pulse width; pulse frequency.
International Journal of Machining and Machinability of Materials, 2013 Vol.14 No.4, pp.342 - 362
Received: 11 Jun 2012
Accepted: 01 Mar 2013
Published online: 26 Dec 2013 *