Characterization of hot extruded Mg/SiC nanocomposites fabricated by casting

• Published in: Journal of materials science Vol. 46; no. 9; pp. 2991 - 2997
• Main Authors: Choi, Hongseok, Alba-Baena, Noé, Nimityongskul, Sunya, Jones, Milton, Wood, Tom, Sahoo, Mahi, Lakes, Roderic, Kou, Sindo, Li, Xiaochun
• Format: Journal Article
• Language: English
• Published: Boston Springer US 01-05-2011; Springer; Springer Nature B.V
• Subjects: Alloys; Austenitic stainless steels; Billet casting; Cavitation; Characterization and Evaluation of Materials; Chemistry and Materials Science; Classical Mechanics; Crystallography and Scattering Methods; Dispersion; Extrusion billets; Grain size; Hot extrusion; Magnesium base alloys; Materials Science; Metal castings industry; Metal matrix composites; Microhardness; Nanocomposites; Nanoparticles; Polymer Sciences; Pressure casting; Silicon carbide; Silicon compounds; Size reduction; Solid Mechanics; Ultimate tensile strength; Ultrasonic testing; Cast Billet; Magnesium Alloy; Ductility; Extrusion Direction; Ultrasonic Probe
• ISSN: 0022-2461; 1573-4803
• DOI: 10.1007/s10853-010-5176-y

Mg–1%SiC nanocomposites were fabricated using an ultrasonic cavitation based casting method, resulting in the dispersion of the reinforcing SiC nanoparticles to form Mg–metal matrix nanocomposite (Mg–MMNC) billets. The MMNC billets were then processed using hot extrusion at 350 °C. Micrographic observations illustrate a significant grain size reduction and the presence of microbands that align the SiC nanoparticles parallel to the direction of extrusion for Mg–MMNCs. Observations from the cross-section at 90° of the extrusion direction show uniform nanoparticles dispersion. Results from the extruded Mg–MMNCs tensile testing at different temperatures (25, 125 and 177 °C) reveal an increase of the yield strength, ultimate tensile strength, and ductility values as compared to the un-reinforced and extruded Mg-alloy; such increase was also observed from the microhardness testing results where an increase from 19 to 34% was measured.