CRYOMILLING AL-CU AND AL-SI ALLOY POWDERS

摘要

The process of mechanical attrition (MA) is based on imposing very high strain on the material powders, which leads to structural refinement by shear and fracture of phase mixtures and by recrystallization of the given phase. Severe plastic deformation can lead to grain sizes as fine as 10 nm. The MA process is characterized by repeating powder welding and fracturing. Nanocrystalline materials can be synthesized by mechanical milling using liquid nitrogen as the milling medium. Cryomilling has been proven to increase fracture in ductile materials as well as improve grain-size refinement. This paper will focus on the novel properties obtained on the Al-Cu and Al-Si systems. Results on grain refinement, solid solubility limit extension and modification of aging behavior of these nanostructured powders will be presented.