Heat Conductivity of Metallic Hollow Sphere Structures: Numerical Simulation and Experimental Validation

Abstract

Heat conductivity is a well-known energy transfer method and it is here applied to the study of metal foams and laser processing. Metallic hollow sphere structures (MHSS), a relatively new group of advanced composite materials, combine the advantages of cellular metals without major scattering of their material parameters. They are characterised by high geometry reproduction leading to relatively constant mechanical and physical properties.The laser processing technology provides not only a laser cutting but also a laser soldering procedure. Within this work a laser cutting process is applied to MHSS. Laser beam cutting is a highly efficient technique to cut materials, because the relatively small amount of heat affects only a small heating zone.Numerical simulation is used in order to define proper process parameters for a large variety of MHSS. The finite element method based simulation covers material parameters as well as process parameters like the cutting velocity. Heat conduction and convection are taken into account and the phase change from solid to liquid state as well. Within the simulations the concept of representative volume element (RVE) is applied. The temperature distribution is the fundamental result.