SIMULATION AND EXPERIMENTAL INVESTIGATION OF MECHANICAL PROPERTIES OF ALUMINIUM COPPER ALLAYS

Abstract

The main objective of this thesis is to fabricate aluminium metal matrix composite using spark plasma sintering process and to analyse its metallurgical and mechanical properties and compare its mechanical properties through numerical analysis, this aim is achievable by Micromechanical modelling. Aluminium Composites exhibit excellent mechanical properties such as hardness, good wear resistance, low creep rate, etc. Powders were prepared by milling it in High Energy Ball Milling (HEBM) and the powders were characterized by x-ray diffraction (XRD) and Field Emission Scanning Electron Microscopy (FE-SEM). Spark plasma sintering has been used for compaction and sintering which is quite advantageous in terms of its properties. The matrix used is AA 2024 and the reinforcement used is yttria (Y2O3) having very good strength with plasma resistance and samples of 2024 AA with yttrium oxide ranging from 1 to 5 wt.% are fabricated by Spark Plasma Sintering (SPS). The mechanical properties like hardness, Ultimate Tensile Strength (UTS) and Yield Strength (YS) are determined and the metallurgical characterization of the samples is evaluated by Scanning Electron Microscopy (SEM), Field Emission Scanning Electron Microscopy (FE-SEM), EDAX and X-Ray Diffraction (XRD). Unreinforced 2024 AA sample is also fabricated as a benchmark to compare its properties with that of the composite developed. Numerical simulation was carried out to generate Al/Y2O3 composite and mechanical behaviour was estimated by considering Representative Volume Element (RVE) of Al/Y2O3 composite. The Simulation was carried out using a recent software called DIGIMAT which is a non-linear multiscale material and structure modelling platform. The Simulation were carried out for different weight fraction of Al/Y2O3 composite. Elastoplastic materials properties, strengthened matrix properties and particle-matrix bonding behaviour are introduced to simulate the mechanical behaviour of Al/Y2O3 composite. The parameter like enough fine meshes, reasonable loads and proper boundary condition were established to enhance the accuracy and reduce the computing cost. The numerical and experimental result were well corroborated. The works makes an effective attempt to establish the relation between the actual composite structure and mechanical behaviour with the particles reinforced metal matrix composite.