Study of the Thermal Stability and Structural Featuresin Nanostructured Aluminum 2024 Alloy Obtained by Cryomilling

摘要

In the present work, the nanostructured aluminum 2024 alloy produced by cryomilling and consolidated by Spark Plasma Sintering (SPS) was investigated. The powder milled in liquid nitrogen shows a distribution of the particle size, ranging between few microns up to about 90 μm.The granulometric classes selected are <25 μm, 25-45 μm, 45-90 μm. For each granulometric classes, the structural and the microstructural features, as well as the transformations involving coherent precipitates (AI-2Cu and AI-2CuMg) and thermal stability were investigated. The analyses are done using X-ray diffraction. The interest on these transformations arises from the awareness that the thermal stability of the nanostructured powder requires a sintering temperature close to 500°C to obtain a full dense material. This effect of the nanostructure on these transformations was investigated.