Composite Based on AlMg Alloys Obtained by Gas Insufflation

Abstract

Composite materials are the most advanced class of materials invented and produced by humans in modern times as well as a challenge for the future in the field of scientific and technological performance. They are made up of at least two phases of different nature which are so combined to form a new material with a superior combination of properties. They are generally materials with unusual performances on the relationship between properties and specific gravity. Composites are multiphase materials with distinct and well-defined interface between the constituent phases ensuring a transfer of property but can lead to obtaining a product with exceptional performance from the starting material. Stabilized Aluminum Foams (SAF) are new class of materials with low densities and novel physical, mechanical, thermal, electrical and acoustic properties. They offer potential for lightweight structures, for energy absorption, and for thermal management; and some of them, at least, are cheap. Metal foams offer significant performance gains in light, stiff structures, for the efficient absorption of energy, for thermal management and perhaps for acoustic control and other, more specialized, applications. They are recyclable and nontoxic. They hold particular promise for market penetration in applications in which several of these features are exploited simultaneously. Metal foams are metal matrix composites (MMC) characterized by: higher specific properties, high capacity vibration damping and sound, mechanical energy absorption etc. The wide range of possible properties can lead to innovative applications, which is a strong driving force for the improvement of metal foam production technologies. Investigated and studied materials are composite of aluminum alloy matrix where the stabilisation of the gas bubbles has been done by ceramic particle added. To obtain SAF we have focused research on Al-Mg alloys with different concentrations of magnesium and silicon carbide (SiC). To obtain these materials has been chosen a different gas blowing method (N₂, SO₂ şi C₄H₁₀). It was observed that the best results in terms of pore volume gave the blowing with C4H10. The samples obtained were analyzed by electron microscopy.