Investigation on Microstructures and Corrosion Properties of In-Situ TiC-TiB2/Al-12Si Hybrid Aluminum Matrix Composites

In-situ TiC-TiB2/Al-12Si hybrid aluminum matrix composites were fabricated by laser deposition. The microstructures and corrosion properties of in-situ TiC-TiB2/Al-12Si hybrid aluminum matrix composites were analyzed by XRD, OM, SEM, TEM and electrochemical test. The results show that the in-situ TiC particles with fine and uniform polygons and the rod-like TiB2 particles can act as the heterogeneous nucleation core of alpha-Al phase to refine grains. With the increasing of in-situ TiC-TiB2 reinforced particles content, the corrosion potential shifts positively, the corrosion current density decreases significantly, and the impedance modulus and phase angle increase gradually, indicating that the in-situ TiC-TiB2/Al-12Si hybrid aluminum matrix composites have better corrosion resistance.