|
Volume 17, Issue 3, 2008
INFLUENCE OF PROCESSING CONDITIONS ON THE MICRO-MECHANICAL PROPERTIES OF PARTICULATE-REINFORCED ALUMINIUM MATRIX COMPOSITES
D. P. Myriounis1,2, S. T. Hasan2 and T. E. Matikas1
1 University of Ioannina, Department of Materials Science & Engineering, Materials Behaviour & Quality Control Laboratory 45110, Ioannina, Greece
2 Sheffield Hallam University, Materials & Engineering Research Institute, City Campus, S1 1WB, Sheffield, UK
Received 3 July 2007; accepted 13 June 2008
ABSTRACT
During processing, metal matrix attempts to deform and this deformation plays the key role in the micro-structural events of segregation and precipitation at the matrix-reinforcement interface. The important aspect of this behaviour is to identify the strengthening micro-characteristics which enhance the material’s interphasial reactions in order to improve the bonding properties of the matrix-reinforcement interface. This work focuses on the non-equilibrium segregation which arises due to imbalances in point defect concentrations set up around interfaces during non-equilibrium heat treatment processing of SiC particle reinforced aluminium matrix composites. The important factors affecting the heat treatment process are the temperature, the cooling rate, the concentration of solute atoms and the binding energy between solute atoms and vacancies. Aluminium – silicon – magnesium alloy matrix reinforced with varying amounts of silicon carbide particles were used in this study. Samples in the as-received and heat treated condition were examined by microstructural and microhardness analyses. Based on the analysis, it has been observed that the macroscopic mechanical behaviour of the composite is influenced by several factors including the manufacturing process, the processing conditions, the inter-particle distance, as well as the mean size and the percentage of reinforcement.
Keywords: Metal matrix composites (MMCs); Heat Treatment; Interfacial strength; Particulates; Precipitation
|
