Journal of Aeronautical Materials (Oct 2023)
Tensile properties of SiC/AZ31 inverse nacre structured composite
Abstract
SiC/AZ31 inverse nacre structured composite was prepared by mechanical ball milling and thermal deformation, and the microstructure of the composite was effectively controlled by process control. The microstructure was characterized by X-ray diffraction（XRD）and scanning electron microscopy（SEM）, the mechanical properties of the material were tested by quasi-static tensile test, and the strengthening and toughening mechanism and failure mechanism were preliminarily analyzed by combining the microstructure. The results show that the inverse nacre structure obtained by hot deformation process can significantly improve the tensile properties. When the strain hardening ability of the matrix in the inverse nacre structured composite is improved, it can better compensate for the softening effect caused by crack propagation in the hard phase, and the strain hardening ability of the composite is improved. The tensile properties can be controlled by adjusting the size of the lamellar soft phase in the inverse nacre structured composite. When the size of lamellar soft phase is large, the composite has better toughness. When the size of lamellar soft phase is small, the composite has higher strength. The excellent strength and toughness of the inverse nacre structure composite are arising from its structural characteristics, and the continuous hard phase plays a good role in bearing, while the dispersed lamellar soft phase benefits for improving the toughness of the composite. The main strengthening mechanisms of this material include dispersion strengthening, fine grain strengthening, and heterogeneous deformation induced strengthening, and the improvement of toughness are attributed to the crack blunting and deflection induced by lamellar soft phase. In summary, the architecture design of inverse nacre structure is an effective way to obtain high-strength and tough magnesium matrix composite.
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