Microstructure and mechanical properties of Al–B4C composite at elevated temperature strengthened with in situ Al2O3 network

• Published in: Rare metals 2020-06, Vol.39 (6), p.671-679
• Main Authors: Feng, Shang-Yang, Li, Qiu-Lin, Liu, Wei, Shu, Guo-Gang, Wang, Xin
• Format: Article
• Language: English
• Subjects: Aluminum boron carbide; Aluminum oxide; Atomizing; Biomaterials; Bonding strength; Boron carbide; Chemistry and Materials Science; Elongation; Energy; Fracture mechanics; Grain boundaries; High temperature; Materials Engineering; Materials Science; Mechanical properties; Metallic Materials; Nanoscale Science and Technology; Physical Chemistry; Powder metallurgy; Raw materials; Sintering (powder metallurgy); Thermal stability; Thermodynamic properties; Ultimate tensile strength
• ISSN: 1001-0521; 1867-7185
• DOI: 10.1007/s12598-019-01279-2

This study evaluated the mechanical properties and thermal properties of Al–12 vol%B 4 C composite at elevated temperature strengthened with in situ Al 2 O 3 network. The composite was fabricated using powder metallurgy (PM) with raw materials of fine atomized aluminum powders, and the associated microstructures were observed. At 350 °C, the composite had ultimate tensile strength of UTS = 137 MPa, yield strength of YS 0.2  = 118 MPa, and elongation of ε  = 4%. Besides, the mechanical properties of the composite remained unchanged at 350 °C after the long holding periods up to 1000 h. The excellent mechanical properties and thermal stability at 350 °C were secured by in situ am-Al 2 O 3 network that strengthened the grain boundaries. The interfacial de-bonding and brittle cracking of B 4 C particles were the main fracture mechanisms of the composite. In addition, the influence of sintering temperature and rolling deformation on the microstructures and mechanical properties was studied.