Development of rare-earth oxides based hybrid AMCs reinforced with SiC/Al2O3: mechanical & metallurgical characterization

The paper presents the study on the mechanical and microstructural behaviour of aluminium matrix hybrid composites of Al-6061 alloy with Al2O3, SiC and CeO2 as reinforcement particles processed through stir casting route. For the experimental investigations, hybrid composites were fabricated by varying weight percentages of 5,10 and 15 wt.-% of (SiC + Al2O3) mixture and weight percentage of 0.5, 1.5 and 2.5 wt.-% of CeO2 keeping total wt.-% of reinforcement less than 30 wt.-%. Mechanical properties like ultimate tensile strength, micro and macro hardness and percentage elongation were examined on the aluminium matrix hybrid composites at room temperature. The microstructure analysis was done using SEM, XRD and EDS techniques. Micro hardness value of the base alloy was increased by 17.02% on addition of 2.5 wt.-% of CeO2 as rare earth element along with (Al2O3 + SiC) mixture. In comparison to non-rare earth element (Alloy + 15 wt.-% (Al2O3 + SiC) mixture), the hardness increased by only 13.70%. Rockwell hardness of the base alloy increased by 33.80% on successful incorporation of rare earth element. The SEM microstructure analysis shows a very significant refinement of the composites after addition of rare earth particles. XRD and EDS analysis shows very good results in terms of fabrication of hybrid composite particles.