2014

Si–SiC–ZrB2 are produced by the reactive infiltration with molten silicon in porous SiC–C–ZrB2 preforms. It is observed that oxidized Si–SiC–ZrB2 ceramics present a layered structure composed of an outer layer of silica and a borosilicate glass intermediate layer with ZrO2 particles and the unoxidized bulk material. The graphs show that the passivation is very effective already after 5 min of oxidation. The thermograms do not vary significantly when the oxidation times are increased.

Performances of metal matrix composites (MMCs) rely strongly on the distribution of particles within the metal matrix but also on the chemical reaction which may occur at the liquid-solid interfaces. This paper presents the chemical reaction between aluminum based particles Al2O3 and Al2O3-AlOOH with magnesium alloys matrixes AZ91 and EL21, respectively, and studies the microstructure of these reinforced composites.

The performance of structural materials is commonly associated with such design parameters as strength and stiffness relative to their density; a recognized means to further enhance the weight-saving potential of low-density materials is thus to improve on their mechanical attributes. The European Community research project ExoMet that started in mid-2012 targets such high-performance aluminum- and magnesium-based materials by exploring novel grain refining and nanoparticle additions in conjunction with melt treatment by means of external fields (electromagnetic, ultrasonic, and mechanical).

In this chapter a large description of additive manufacturing techniques for obtaining Al alloys and Al matrix composites is given. Results on mechanical properties, roughness and microstructure achievable with such fabrication route on Al alloys are reported