Microstructure and mechanical properties of high strength Al—Mg—Si—Cu profiles for safety parts

International Conference on Materials, Processing and Product Engineering 2015

Österreicher, J.A.^1 ; Schiffl, A.^2 ; Falkinger, G.^1 ; Bourret, G.R.^3

LKR Leichtmetallkompetenzzentrum Ranshofen GmbH, Austrian Institute of Technology, Postfach 26, Ranshofen

5282, Austria^1

Hammerer Aluminium Industries Extrusion GmbH, Lamprechtshausener Straße 69, Ranshofen

5282, Austria^2

Department of Materials Science and Physics, University of Salzburg, Hellbrunner Straße 34, Salzburg

5020, Austria^3

关键词: Fracture surfaces;    Intermetallic phasis;    Microstructure and mechanical properties;    Properties and microstructures;    Quasi-static compression;    Strength and ductilities;    Three-point bending test;    Uniform elongation;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/119/1/012028/pdf
DOI  :  10.1088/1757-899X/119/1/012028

来源: IOP

【 摘 要 】

Aluminium extrudate used for safety parts in cars need to exhibit high yield strength and ductility, a combination that is not easily achieved. In this work, the mechanical properties and microstructure of profiles with a yield strength greater than 280MPa achieved by two different artificial ageing treatments were studied. Profiles from one of the heat treatments performed well in quasi-static compression testing while those from the other heat treatment clearly failed. The batch of profiles that failed showed higher uniform elongation in tensile testing but a lower reduction in area. However, the difference in bending angles in the three-point-bending test were not as pronounced. Microscopic investigation of polished sections and fracture surfaces revealed that failure is dominated by the fracture of intermetallic phases resulting in voids. The growth and coalescence of these voids is facilitated by another population of smaller voids within the matrix, presumably nucleating at secondary phases.