Metal Foams

The response of a blast mitigation cladding consisting of a face sheet and metal foam core subjected to a close-range blast is predicted. While the cladding is sufficiently wide compared to the standoff distance between the explosion center and the cladding, the boundary of the blast induced bulge is released. The face sheet is considered as a rigid perfectly plastic membrane as the deformation of the sheet always exceeds half its thickness. A procedure predicting the depth and extent of the bulge is proposed with energy method. Subsequently, the minimum thickness of the foam layer is calculated based on the bulge depth. This design-oriented approach, in a ready-to-use manner, can be straightforwardly applied, facilitating the preliminary design of blast mitigation claddings with metal foam core.

In recent years, the use of open-cell meal foams in thermal applications have increased due to their random open pores nature that gives them an improved heat transfer performance. Most of the work done in the literature on metal foam heat sinks investigates their thermal behavior by means of experiments. These experiments are limited in the parameters that can be measured due to the complex geometrical nature of metal foams. This pushed for the use of advanced computational techniques to analyze their behavior. In this work, l-CT scan is used to develop an accurate 3D representation of the metal foam fins used in the heat sinks. The model is used to create a computational FE model that is used to perform a wide range of simulations. The model is calibrated and validated against a range of experiments that are performed for the same metal foam sample. The 3D model is used to study the effect of assembly method between the heat sink base and the metal foam fin, by comparing the traditionally used thermal adhesives to a new technique utilizing thermal spraying. In addition, effect of forced convection, fin orientation , and number of fins on the efficiency, effectiveness, and thermal resistance. The model is also used to calibrate the heat transfer coefficient, which is very difficult to calculate analytically or experimentally due to the complex geometrical nature of metal foams.

Metal matrix composite foams based on 316L stainless steel and reinforced with TiC0.7N0.3 were produced by the replication method using polyurethane sponge as a template. The rheological properties of the slurry appeared to be the key issue in the preparation of the composite foams. A homogeneous distribution of  TiC0.7N0.3 particles throughout the 316L matrix and a good interaction between the 316L matrix and TiC0.7N0.3 reinforcement particles were obtained. Compression strength results showed that TiC0.7N0.3 particles acted as the real reinforcement medium. The values of the compressive yield strength and the elastic modulus of the metal matrix composite foams increased significantly with increasing TiC0.7N0.3 content when compared to the open cell 316L stainless steel foams.

ABSTRACT The chapter describes the state of the art of titanium foam for tissue attachment and, in particular, for the implant osseointegration as final application for the bone tissue reconstruction. The chapter introduces the description of the titanium alloys used for biomedical applications. Next, a section on the processing techniques for the foaming of the titanium or titanium alloys as well as the surface treatments for the control of physical and chemical surface properties is reported. Such overview aims at empathizing the range of technological approaches to obtain functional biomedical foams. Furthermore, a section on methods for endowing titanium surfaces with biomolecules for tissue integration is included. Finally, a survey on the tissue response to the material implantation is presented with a focus on the titanium interfaces previously described.

In the present work a numerical and experimental investigation regarding laser assisted foaming inside a hollow profile was carried out. The aim was to examine experimentally the feasibility of the laser foaming through laser irradiation of a steel hollow profile, which contains the aluminium foamable precursor. Experimental activity showed that three process parameters have to be taken into account: interaction time, laser energy density and total amount of beam energy delivered towards the work-piece. Numerical simulation allowed the qualitative evaluation of the temperature field inside the solid precursor with the purpose to better understand the process parameters modification effect.