Title: A new model of percussion laser drilling

Authors: N.D. Pandey, H.S. Shan, T. Mohandas

Addresses: Defence Metallurgical Research Laboratory, Kanchanbagh, 500 058 Hyderabad, AP, India. ' Department of Mechanical and Industrial Engineering, Indian Institute of Technology Roorkee, 247 667 Roorkee, India. ' Defence Metallurgical Research Laboratory, Kanchanbagh, 500 058 Hyderabad, AP, India

Abstract: Manufacturing industries in strategic and other hi-tech areas are increasingly using the percussion mode of laser drilling for component development. In this paper, the optothermal effects of laser-metal interaction are analysed from a modelling viewpoint. A model of percussion laser drilling is presented that considers melt displacement/fracture in the semi-solid or solid state together with material removal by melt expulsion and evaporation. Predicted von Mises stresses (due to thermal strain in vicinity of the hole) exceed the tensile strength of the workpiece material (SUPERNI 263A) which are likely to displace/fracture material in vicinity of the hole. The model agrees well with our experimental findings.

Keywords: percussion laser drilling; modelling; fracture; material removal; finite element method; FEM; Nd:YAG lasers; nickel based superalloys; SUPERNI 263A; optothermal effects; laser-metal interaction; melt displacement; thermal strain; stress; tensile strength.

DOI: 10.1504/IJCAT.2006.010767

International Journal of Computer Applications in Technology, 2006 Vol.26 No.4, pp.218 - 232

Published online: 30 Aug 2006 *

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