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Room and high temperature tensile tests on the AA6061/10vol.%Al 2 O 3 p and AA7005/20vol.%Al 2 O 3 p composites
Author(s) -
Ceschini L.,
Morri A.,
Cocomazzi R.,
Troiani E.
Publication year - 2003
Publication title -
materialwissenschaft und werkstofftechnik
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.285
H-Index - 38
eISSN - 1521-4052
pISSN - 0933-5137
DOI - 10.1002/mawe.200390077
Subject(s) - materials science , composite material , ultimate tensile strength , coalescence (physics) , aluminium , ductility (earth science) , nucleation , alloy , ceramic , void (composites) , composite number , aluminium alloy , creep , physics , chemistry , organic chemistry , astrobiology
Abstract Aluminium alloy based Metal Matrix Composites (MMCs), reinforced with ceramic particles such as Al 2 O 3 or SiC, have a number of advantages over conventional aluminium alloys, primarily enhanced stiffness and increased wear resistance. In order to improve the fields of application, fundamental understanding of the relationship between microstructural features and mechanical properties is however required. In this work, the tensile behaviour of two composites based on 6061 and 7005 aluminium alloys, reinforced with Al 2 O 3 particles, at room temperature, at 100°C and at 150°C was studied. The ductility of the composites was found to be much lower than that of the unreinforced alloys, while a significative increase of the elastic modulus and tensile strength was found. Both materials showed a slight decrease of the tensile strength with temperature, while elongation increased. Large particles and clusters of the reinforcement were found to be locations prone to failure in the composite, due to the high stress concentrations, mainly at room temperature. With increasing temperature, the fracture surfaces showed a dimpled appearance with a large amount of plastic deformation of the matrix, indicating that void nucleation, growth and coalescence is the main fracture mechanism.