Nanostructured Al Powder Obtained by High Energy Ball Milling at Ambient and Cryogenic Temperatures

Abstract

High performance nanostructured light metals and alloys are very interesting for replacing conventional heavier materials in many industrial components. High Energy Ball Milling and Cryomilling are useful techniques to obtain nanocrystalline powders. In this work the effect of several milling conditions such as rotation speed, time, ball to powder ratio and temperature on the crystallite and particle size and morphology in pure aluminum are presented. X-Ray Diffraction, Laser Diffraction and Scanning Electron Microscopy are used. High energy ball milling at ambient and cryogenic temperature of Al powders rapidly leads to a nanometer size down to about 35 nm. High ball to powder ratio promotes both low crystallite and particle size. Small crystallite size like 18 nm and particle size as 4 μm were achieved in the most energetic conditions at ambient temperature. Isopropyl alcohol used as liquid media and protective atmosphere has a strong influence on the results depending on the milling temperature of Al.

Nanostructured Powders of AA7075 - SiC Manufactured by High-Energy Ball Milling in a Bath of Isopropyl Alcohol

“…For each sample, 50g of material was manufactured at a bath of 100ml isopropyl alcohol (C3H7OH -99,82%) and 1wt% of zinc stearate (C36H70O4Zn) was used as process control agent (PCA). The process temperature of 25ºC was maintained via a jacket refrigerated with water around the attritor mill 40 .…”

Manufacturing of AA7075 Aluminum Alloy Composites Reinforced by Nanosized Particles of SiC, TiN, and ZnO by High-Energy Ball Milling and Hot Extrusion

“…For each batch, 50 g of nanocrystalline powders AA7075 alloy was put in stainless steel attritor mill developed by the UFPE, equipped with a K-type thermocouple and a temperature controller. In all cases, milling was carried out for 480 minutes at 900 rpm, with a 20:1 ball-to-powder weight ratio (BPR) using 6.4 mm stainless steel balls 100C6 (1 %C, 1.5 %Cr), 1 wt% of zinc stearate (C36H70O4Zn) as process control agent (PCA), a bath of 100 ml isopropyl alcohol (C3H7OH -99.82 %) as liquid media milling, and the process temperature (25 ºC) maintained via a water refrigerated jacket, around the attritor mill 23 .…”