Dependence of microstructure characteristics and mechanical properties on nanosize SiCp contents in Mg–9Al matrix composites fabricated by ultrasonic-assisted semisolid powder hot pressing

• Published in: Journal of materials research Vol. 33; no. 18; pp. 2689 - 2699
• Main Authors: Li, Gang, Li, Ming, Wang, Hongxia, Zhang, Zengyao, Cheng, Weili, Liang, Wei, Zhang, Changjiang
• Format: Journal Article
• Language: English
• Published: New York, USA Cambridge University Press 28.09.2018; Springer International Publishing; Springer Nature B.V
• Subjects: Alloys; Aluminum; Applied and Technical Physics; Biomaterials; Densification; Density; Dependence; Ductility; Elongation; Energy consumption; Grain boundaries; Grain size; Hot pressing; Inorganic Chemistry; Load transfer; Magnesium base alloys; Materials Engineering; Materials research; Materials Science; Mechanical properties; Microscopy; Microstructure; Morphology; Nanocomposites; Nanoparticles; Nanotechnology; Particle size; Particulate composites; Plasma sintering; Powder metallurgy; Semisolids; Silicon carbide; Tensile strength; Ultimate tensile strength; Yield stress; strengthening mechanism; microstructure; semisolid powder hot pressing; magnesium matrix composites; mechanical properties
• ISSN: 0884-2914; 2044-5326
• DOI: 10.1557/jmr.2018.182

Nanosize SiCp (n-SiCp) reinforced Mg–9Al matrix composites (Mg–9Al–xSiC, x = 2.5, 5, 7.5, 10 wt%) with nearly full densification are fabricated by the semisolid powder hot pressing technique assisted with ultrasonic. The effect of SiC nanoparticle contents on microstructures and mechanical properties of the composites is systematically investigated. Grain size and density of Mg–9Al–xSiC composites and morphology of bonding interfacial between the n-SiCp and matrix are found to be greatly dependent on the n-SiCp contents, resulting in the strength and ductility of the composites increase first and then decrease as the increase of n-SiCp contents. As the SiCp content increasing to 7.5 wt%, superior mechanical properties with the yield strength of 191 MPa, ultimate tensile strength of 248 MPa, and elongation to failure of 5.3% are achieved. The improved mechanical properties could be attributed to grain boundary strengthening, Orowan strengthening, and load transfer strengthening.