Development of quasicrystalline metal metal composites with high mechanical performance

M. GALANO; F. AUDEBERT; N. ROUNTHWAITE; S. PEDRAZZINI; G. W. SMITH

Salvador

Congreso; RQ14 - The 14th International Conference on Rapidly Quenched and Metastable Materials; 2011

In the recent years Al-Fe-Cr-TM (TM: transtion metals) quascristalline alloys counting with a microstructure composed of quasicrystals of a nanometric size embedded in an a-Al matrix were developed. These alloys generally produced by melt spinning showed high strength at elevated temperatures in comparison with commercial Al based alloys. Therefore, they have become promising new high strength nanocomposites to be applied at elevated temperatures in the automotive and aeronautical industries due to the increased stability of the quasicrystalline phase delaying the microstructural transformation to higher temperatures. However for the potential of these systems to be fully exploited a combination of mechanical properties such as strenght and toughness should be achieved. In the present work a range of nanocomposites counting with a quasicrystalline alloy matrix with different types of additions acting as reinforcements or plasticizers, have been developed by powder atomisation and extrusion. The microstructure of the atomised powders and extruded nanocomposite bars was characterised by means of XRD, SEM, TEM, and EDX and DSC. The relationship between the mechanical properties and the microstructure is being analysed. The mechanical behaviour has been studied by tensile and compression tests at room temperature and elevated temperature. In addition, dynamic compression tests were used to characterise the composites.