Influence of Mechanical Surface Treatments on Notched Fatigue Strength of Magnesium Alloys

Author:  Kuster, Hilpert, Kiefer, Wagner
Source:  Conf Proc: ICSP-8 Sept. 16-20, 2002 Garmisch-Partenkirchen, Germany
Doc ID:  2002047
Year of Publication:  2002
Abstract:  
Authors Bodo Kuster 1), Matthias Hilpert 2), Armin Kiefer 3) and Lothar Wagner 1) 1) Chair of Physical Metallurgy and Materials Technology, Technical University of Brandenburg at Cottbus, Cottbus, Germany 2) Otto Fuchs Metallwerke, Meinerzhagen, Germany 3) OSK Kiefer, Oppurg, Germany Introduction High-strength wrought magnesium alloys are considered as potential candidates for application as suspension parts in future automobiles due to their high strength to weight ratio [1-3]. For this application, good HCF performance of notched components is one of the most demanding requirements. While previous work on magnesium alloys has demonstrated to what extent mechanical surface treatments such as shot peening and roller-burnishing can increase the HCF strength of smooth specimens compared to an electropolished reference [4-7], corresponding results on notched specimens are not available yet. From earlier work on titanium and aluminum alloys [8-10], it is known that particularly notched components beneficially react to mechanical surface treatments such as show peening or deep rolling. This result was explained by the interaction of the notch root stress field with the process-induced residual compressive stresses affecting mainly microcrack growth. In addition, the triaxial stress state at the notch root was thought to result in residual stresses being more stable during cyclic loading compared to those in the surface layer of smooth specimens.