Extruded Al-Al2O3 composites formed in situ during consolidation of ultrafine Al powders: Effect of the powder surface area

被引：58

作者：

Balog, Martin ^{[1
]}

Simancik, Frantisek ^{[1
]}

Walcher, Martin ^{[2
]}

Rajner, Walter ^{[2
]}

Poletti, Cecilia ^{[3
]}

机构：

[1] Slovak Acad Sci, Inst Mat & Machine Mech, Bratislava, Slovakia

[2] NMD New Mat Dev GmbH, St Pantaleon, Austria

[3] Graz Univ Technol, Inst Mat Sci & Welding, A-8010 Graz, Austria

来源：

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING | 2011年 / 529卷

关键词：

Aluminium; Extrusion; Metal matrix composites; Powder metallurgy; SAP; ALUMINUM POWDERS; PARTICLES;

D O I：

10.1016/j.msea.2011.09.006

中图分类号：

TB3 [工程材料学];

学科分类号：

0805 ; 080502 ;

摘要：

Twenty-five samples of commercially available, gas-atomised Al (99.5%) powders with particle sizes <10 mu m were hot extruded into Al-Al2O3 composites formed in situ during extrusion. The effect of particle size, surface area, oxygen content and atomisation atmosphere of the powder on the microstructure and mechanical properties of the extruded compacts were studied by Brunauer, Emmett, Teller (BET) analysis, hot gas extraction, scanning electron microscopy (SEM), electron backscatter diffraction (EBSD), transmission electron microscopy (TEM) and tensile tests. Thermal stability of the compacts and the individual strengthening mechanisms operating in the compacts were discussed. It was found that the properties of the compacts stemmed from the extraordinary grain boundary strengthening effect of the ultrafine-grained compacts due to their microstructures. The efficiency of the grain boundary strengthening was significantly enhanced by the presence of nano-metric Al2O3 dispersoids introduced in situ. The strength of the compacts was closely related to the surface area of the powder particles. In addition, the entrapped gasses and chemically bonded humidity had a negative effect on the mechanical properties of the compacts. (C) 2011 Elsevier B.V. All rights reserved.

引用

页码：131 / 137

页数：7

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