Thermo mechanical behaviour of metal matrix composite structures

Abstract

Metal matrix composites offer a very good performance in a wide temperature range, but are limited to few applications due to high production costs. A novel compound extrusion process developed within the collaborative research centre SFB/TR 10, supported by the German Research Foundation (DFG – Deutsche Forschungsgemein-schaft), provides an economical production method for reinforced aluminium profiles. Using different reinforcement fractions it is possible to increase the strength of these components locally and to reduce the macroscopic coefficient of thermal expansion (CTE) and thus to tailor mechanical as well as thermal properties. For application in frame struc-tures, an efficient approach for sizing these properties is necessary, especially in regions with a 3D stress state. There-fore an approach is shown based on data gained analytically and with numerical analyses, allowing a dimensioning of cross sections required. The applicability of this approach is shown using a finite element (FE) model of a bent rein-forced aluminium profile. To verify the failure of the profile an own developed failure criterion was applied which is based on a test program, including classical tensile tests in direction of extrusion and perpendicular to it. Furthermore the process of biaxial testing of extruded profiles with small dimensions is shown.