Effect of the Milling Time and Addition of a Grinding Agent of Quasicrystalline Powder Based on AlCuFeB Alloys

Abstract

Quasicrystalline (QC) materials represent a new class of alloys differing from amorphous and crystalline materials due to quasicrystalline periodicity and therefore unusual properties. Applications of quasicrystals range from surface coatings, thin films to reinforcements of ductile matrix composites such aluminum and, more recently, polymers. Quasicrystalline alloys show fundamentally different behavior compared to crystalline alloys even when their compositions are very similar, including low friction coefficient, high hardness and high brittleness. Due to this brittle behavior there are some limitations with respect to what methods can be used to process QC materials restricting their applications to powder form. One of the techniques for particle size reduction is mechanical milling which, however may lead to destabilization of the icosahedral phase. Therefore, there is a need to study the stability of quasicrystalline alloys during this comminution process. In the present study, AlCuFeB alloys were milled with the aid of a grinding agent that helps reduce overheating and thus controlling the QC powder stability. It was found that QC phase was destabilized after 10 h while the addition of a grinding agent led to milling times of 20 h without destabilizing the QC phase.