Ni-MF/Al2O3 composite was fabricated using traditional method. The specimens covered with graphite were sintered at 1400°C, and the microstructure and mechanical properties of Ni-MF/Al2O3 composites were studied. Results showed that the flexural strength and fracture toughness of the composites were dramatically changed with the content of nickel. When the content of Ni was 15 wt% and no-coated MF was 10%, the composite obtained better mechanical properties, its flexural strength and fracture toughness were up to 734.40 MPa and 10.17 MPa•m1/2 respectively. The toughening mechanisms of the composites were attributed to the fiber extraction and debonding, metal bridging and deforming plastically.

The composites of Fe/Al2O3 gradient coatings on steel substrate were prepared by spraying and sol-gel method, and the microstructure and performances of the composites were analyzed. The results show that the adhesion strength of Fe/Al2O3 gradient coatings with FeAlNi transitional layers reaches 25.3MPa when the sintering temperature is 1220°C, and the surface hardness of coatings is four times higher than that of steel substrate. The coatings are mainly composed of α-Al2O3, AlFeO3 and NiFe2O4. There is no obvious hole or macro-interface, while some organization similar to the branch appears in the coatings. The bonding of Fe/Al2O3 gradient coatings and steel substrate mainly depends on adsorption, diffusion and chemical combination.