Fabrication of a new SiC/2024Al co-continuous composite with lamellar microstructure and high mechanical properties

• Published in: Journal of alloys and compounds 2014-02, Vol.585, p.146-153
• Main Authors: Liu, Qiang, Ye, Feng, Gao, Ye, Liu, Shichao, Yang, Haixia, Zhou, Zhiqiang
• Format: Article
• Language: English
• Subjects: Alloys; Aluminum base alloys; Applied sciences; Ceramics; Elasticity. Plasticity; Exact sciences and technology; Freezing; Mechanical properties; Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology; Metal matrix composites; Metals. Metallurgy; Microstructure; Powder metallurgy. Composite materials; Preforms; Production techniques; Scanning electron microscopy; Silicon carbide; Technology
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2013.09.140

•New SiC/Al co-continuous composites with lamellar microstructure have been prepared.•Porous SiC preforms with excellent permeability were produced by freeze casting.•The composites were fabricated by squeezing molten 2024Al alloy into SiC preforms.•Microstructure of the composites can be precisely tailored by SiC preforms.•These composites possess excellent flexural strength and fracture toughness. New SiC/2024Al co-continuous composites with lamellar microstructure have been successfully fabricated via squeezing molten 2024Al alloy into porous SiC preforms produced by freeze casting. During the process, the porosity and microstructure of porous SiC preforms was well controlled by initial solid loading and freezing temperature, consequently, the content and architecture of ceramic reinforcement in the final co-continuous composites was precisely tailored. The microstructure and mechanical properties of the prepared composites were studied, and the effects of initial solid loading and freezing temperature on the microstructure and mechanical properties for the final composites were investigated. The results showed that these new co-continuous composites exhibit lamellar microstructure composed of alternating ceramic and metallic lamellar. They possess high flexural strength, fracture toughness and hardness due to few defects, lamellar microstructure and well bonded interfaces between the metal and ceramic phase, with the highest strength and toughness of 931.3MPa and 18.8 MPam1/2 respectively in the direction parallel to the freezing direction.