Aluminium Matrix In-Situ Particle Reinforced Composities by Chemical Reaction

摘要

Dispersion of fine particles in a metallic matrix is an attractive method of improvement of strength and wear resistance. These particles/dispersions are either added ex-situ or produced in-situ taking help of chemical reaction. The present study reports the preparation and characterization of in-situ aluminium-2% magnesium alloy matrix composites with addition of reactive oxides to molten aluminium. The oxides tried are of titanium and mangnese. Vortex method was used to get a good distribution of the oxides. The reaction products as identified by x-ray diffraction and EPMA are magnesium aluminate and magnesium oxide. The reactions also release elemental metal titanium and magnesium. The problems with this method of producing composites are the porosity associated with the particles and difficulty in controlling the reaction. The composites thus obtained give better strenght and wear resistance even though the volume percentage of reinforcement is low because of finer size of the particles and stable interface which is produced in-situ. The method will prove to be a cheap method producing in-situ composites if the solidification parameters can be optimized.