Integral Foam Molding of Light Metals : Technology, Foam Physics and Foam Simulation

A person with a new idea is a crank until the idea succeeds. Mark Twain Metal foams show outstanding properties: Low weight, high rigidity, high energy absorption capacity, high damping capacity, etc. They have attracted strong - dustrial and scienti?c interest during the last decade. A variety of methods has been developed to produce foams and the development of new, more sophisticated methods is still going on. On the one hand, there are only very few applications where metal foams can be directly employed without further processing. On the other hand, established metal foam production methods have one feature in common, they produce foam and not metal parts containing metal foam. In the majority of cases additional shaping and joining steps are necessary to transform the metal foam into a working functional element. In addition, the cellular structure demands for appropriate joining technologies which are often not yet available or expensive. As a result, the whole processing sequence is in general long and expensive. The logical consequence of the requirement to develop cost-e?ective techniques to produce metal parts with integrated cellular structure is the newly developed process of integral foam molding. Integral foam consists of a solid skin and a c- lular core. This is the fundamental construction principle which is ubiquitous in biological systems, e. g. the human skull, as well as in technical solutions, e. g. sa- wich constructions. The concentration of the material within the skin optimizes the moment of inertia and thus sti?ness and strength.

The development of cost-effective techniques to produce metal parts with integrated cellular structure is the newly developed process of integral foam molding.
This book shows in three parts the technology, the fundamentals and the simulation models for the  Integral Foam Molding of Light Metals

Part I: “Technology” shows for the first time that foaming of metals is possible by applying molding techniques very similar to polymer integral foam molding. It introduces and discusses in detail a low pressure and a high pressure process of foam molding.
 
Part II: “Physics” is devoted to the physics of foaming with special emphasis on the very short time scale which is characteristic for integral foam molding. Although very complex in detail, foam formation is shown to underlie simple evolution laws determined by the way how foam stabilization is realized.
 
Part III: “Numerical Simulation” presents a new lattice Boltzmann approach for the treatment of free surfaces is developed and applied on foam evolution problems. For the first time, the numerical simulation of foam evolution starting from nucleation until decay is accessible. The interplay between hydrodynamics, capillary forces, gravity and bubble coalescence processes leads to complex phenomena such as topological rearrangements, avalanches, drainage, etc. without further model assumptions.