Please use this identifier to cite or link to this item: http://hdl.handle.net/1959.3/210562

Title

An empirical equation for crack formation in the laser cutting of ceramic plates

Author(s)

Lu, G.;  Siores, E.;  Wang, B.

Abstract

Industrial lasers have found many applications in materials processing and manufacturing, one of which is to cut ceramic components that are difficult to cut using conventional means due to their high value of hardness and degree of brittleness. However, often one problem associated with this process is the formation of cracks that can result from the thermal stresses that are induced. This paper is concerned with the problem of cracking of ceramic plates when cut using laser beams. Based on the experimental results reported, it is argued that the most relevant operating parameters are the laser power (P) and the feed-rate of the specimens (v). The material properties of interest in this study are: specific heat (c), conductivity (k) and thermal expansion coefficient (alpha). The only geometrical dimension is the thickness (t). Dimensional analysis was employed to identify four dimensionless groups. On the hypothesis that crack occurs when the tensile strain reaches the material’s critical (fracture) strain, the following empirical equation was obtained, which specifies the safe region in terms of the operating power and feed-rate: P ≥ 1.78 x 10^11t^2.41v where P is in W, t is in m, and v is in m s^-1. Qualitative explanations are discussed in relation to the functional dependence of the various parameters. The identified dimensionless groups and empirical equations are of direct use to practising engineers.

Publication type

Journal article

Research centre

Swinburne University of Technology. School of Engineering and Science

Research centre

Swinburne University of Technology. Industrial Research Institute Swinburne

Source

Journal of Materials Processing Technology, Vol. 88, no. 1 (Apr 1999), pp. 154-158

Publication year

1999

FOR Code(s)

0910 Manufacturing Engineering;  0912 Materials Engineering;  0913 Mechanical Engineering

Keyword(s)

Brittleness;  Degree of brittleness;  Empirical equations;  Hardness;  Industrial lasers

Publisher

Elsevier

ISSN

0924-0136

Publisher URL

http://dx.doi.org/10.1016/S0924-0136(98)00384-7

Copyright

Copyright © 1999 Elsevier Science S.A. All rights reserved.

Peer reviewed