Cold spraying was used to prepare Al/Al₂O₃ composite coatings. The Al₂O₃ content was controlled to increase the mechanical property and corrosion resistance of the composite coating. The inclusion of Al₂O₃ particles results in considerable plastic deformation of Al particles and grain size refinement in the coating. Additionally, the coating’s surface roughness decreased from 24.63 μm to 9.02 μm, and the porosity decreased from 6.34% to 2.07%. The increase in microhardness of the composite coatings was attributed to the combined effect of residual compressive stress, second phase strengthening of Al₂O₃, and plastic hardening of Al particles. The electrochemical test results indicate that the mass fractions of Al₂O₃ significantly affected the corrosion resistance of the Al/Al₂O₃ composite coating. Compared to the Al coating, the composite coating exhibited improved corrosion resistance, with a reduction in corrosion current density from 1.09 × 10⁻³ A/cm² to 2.67 × 10⁻⁶ A/cm² and an increase in corrosion potential from −1.57 V to −1.14 V. However, when the alumina particle content exceeded 17.7%, it led to more Al₂O₃ particle breakage, increasing the weak bonding interfaces in the composite coating, and consequently reducing its corrosion resistance.

In this work, a novel superelastic NiTi fiber reinforced NiTi/(Al₃Ti+Al₃Ni) metal-intermetallic laminated (SFR-MIL) composites was fabricated via vacuum hot pressing method. In order to accurately determine the reaction products of the fabrication process, the microstructure and phase constituents were analyzed and determined using scanning electron microscopy (SEM), energy dispersive spectroscope (EDS) and x-ray diffraction (XRD). Results showed that Al₃Ti and Al₃Ni were formed during fabrication process. In addition, the quasi-static tensile testing results indicated the average UTS and failure strain of SFR-MIL composite are 377.0 MPa and 15.4%, respectively. The compressive tests of SFR-MIL composites manifested that the average peak compressive strength of this class of materials with load perpendicular to layers is 1114.3 MPa, equivalent to or higher than that of some other laminated composites. Then, the fracture mechanisms are discussed, and the results showed that the reaction band is the possible crack initiation due to the stress concentration, and the major fracture mechanisms are intergranular and transgranular fracture modes.