Manufacturing of cast A356 matrix composite reinforced withnano- to micrometer-sized SiC particles

• Published in: 稀有金属：英文版 2017, Vol.36 (1), p.46-54
• Main Author: Reza Taherzadeh Mousavian Rasoul Azari Khosroshahi Sasan Yazdani Dermot Brabazon
• Format: Article
• Language: English
• Subjects: Aluminum; composite; Extrusion; matrix; Semisolidcasting
• ISSN: 1001-0521; 1867-7185

In this study, large micron-sized SiC particleswere fragmented via ball-milling process in the presence ofiron and nickel powders, separately, to fabricate compositepowders of Fe-SiC and Ni-SiC. Continuous fracturing ofbrittle SiC powders leads to the formation of multi-modal-sized SiC powders with size of from 50 nm to slightlyhigher than 10μm after 36-h ball milling. The milledpowders were then incorporated into the semisolid melt ofA356 aluminum alloy to ease the incorporation of fine SiCparticles by using iron and nickel as their carrier agents.The final as-cast composites were then extruded at 500℃ with a reduction ratio of 9：1. Lower-sized compositepowders with slight agglomeration are obtained for the36-h milled Ni-SiC mixture compared to that of Fe-SiCpowders, leading to incorporation of SiC particles into themelt with a lower size and suitable distribution for the Ni-SiC mixture. It is found that lower-sized composite parti-cles could release the fine SiC particles into the melt moreeasily, while large agglomerated composite particlesalmost remain in its initial form, resulting in sites of stressconcentration and low-strength aluminum matrix compos-ites. Ultimate tensile strength （UTS） and yield strength（YS） values of 243 and 135 MPa, respectively, areobtained for the aluminum matrix composite in whichnickel acts as the carrier of fine ceramic particles.