Rietveld refinement of powder X-ray diffraction, microstructural and mechanical studies of magnesium matrix composites processed by high energy ball milling

Abstract

This research reports the processing of magnesium matrix composites reinforced with silicon carbide (SiC) and aluminium oxide (Al2O3) using powder metallurgy technique through high energy milling. Samples of Mg–SiC and Mg–Al2O3 composites subjected to high energy ball milling for different vol% of secondary particles 20, 30 and 40% of SiC and Al2O3 are studied by X-Ray diffraction technique. The rietveld method as implemented in the Fullprof program is applied in order to determine the quantities of the resulting crystalline phases and amorphous phases at each stage of the mechanical treatment. Microstructural examination is carried out using Scanning Electron Microscope (SEM). In addition, crystal structural analysis using appropriate size and strain models is performed in order to handle the distinctive anistrophy that is observed in convinced crystallographic directions for the magnesium composite. The results are furnished in terms of crystalline domains size enlargement of the magnesium composites phases upon prolonged milling duration and discussed in the light of up to date views and theories on crystal growth of nanocrystaline materials. The hardness of the composite samples is calculated by Vickers's Hardness tester. Further, dry sling wear test and corrosion test are performed for the fabricated composites. Composite with 30% secondary particles incorporated magnesium composites exhibits better wear and corrosion resistance than the other composites. Keywords: Rietveld refinement, X-ray diffraction, Crystal structure, Micro structure, Wear and corrosion