Laser Machining and its Associated Effects

  • C. T. Pan
  • H. Hocheng


Laser machining has a wide range of industrial applications. However, laser energy can cause thermal damage to composite materials during the shaping operation following curing. Such damage leads to poor assembly tolerances and reduces long-term performance. In this study, we investigated the laser machining-induced formation of anisotropic heat-affected zones (HAZs) in fiber-reinforced plastics (FRP). The degree of HAZ is estimated by the isotherm of the matrix char temperature. Analysis revealed that both the laser energy per unit length and the fiber orientation-dependent thermal conductivity are key factors in determining the extent of HAZ. An experimental measurement of anisotropic thermal conductivity for composite materials is developed. Heat conduction is greater along fibers than it is across a fiber section, thus laser scanning direction relative to fiber orientation affects the HAZ geometry. The study also investigated the principal-axis and nonprincipal-axis grooving of unidirectional (UD), [0/90], Mat, and MatUD laminates. An analytical model based on a moving point heat source using the Mirror Image Method and immersed heat source to model principal-axis grooving is adopted to correlate HAZ anisotropy with various process parameters. Finite difference method (FDM) with an isotherm conductivity model and eigenvalue method is applied to simulate the HAZ resulting from nonprincipal-axis grooving.


Laser Heat-affected zone Anisotropic heat conduction Composite materials 


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Copyright information

© Springer Science+Business Media New York 2013

Authors and Affiliations

  1. 1.Department of Mechanical and Electro-Mechanical EngineeringNational Sun Yat-Sen UniversityKaohsiungTaiwan, ROC
  2. 2.Department of Power Mechanical EngineeringNational Tsing Hua UniversityHsinchuTaiwan, ROC

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