Modelling and simulation of continuous metal foaming process

摘要

Metal foams have recently gained a lot of technical interest, e.g. within the automotive industry, due to their reduced weight and interesting material properties. In this paper, a computational model is presented, which allows the simulation of static and dynamic metal foam production processes. The metal foaming process is based on a procedure whereby a pre-compacted material consisting of a base metal plus a foaming agent is heated up to a certain foaming temperature. The heating process leads to partial metal melting as well as to the release of the reacting propellant gas and consequently to the material foaming in the semi-solid state. Mathematical models of the different relevant physical subprocesses and effects during the metal foaming process are derived in this paper. For investigation of the conventional static metal foaming process, the geometry of a foamable material (round disc) is selected first and the foaming process is computed by means of one- and two-dimensional models. In addition to the computed foam geometry, further foam characteristics like global density, temperature distribution and time evolution of the species concentrations taking part in the decomposition chemical reaction have been determined within the foaming process from numerical simulation. Finally, the simulation of a new dynamic (continuous) metal foaming process within specifically designed nozzles is accomplished. The numerical results obtained are compared with experiments. [References: 20]