TC4 micro-arc oxidation (MAO) coatings were prepared by adding SiO2 nanoparticles and sodium silicate to the sodium meta-aluminate-based electrolyte. The effect of additives was systematically investigated using XRD, SEM, EDS, electrochemical, and wear tests. The additives could considerably accelerate the formation of MAO coatings. The coatings were mostly composed of rutile and anatase TiO2, α-Al2O3, γ-Al2O3, Al2TiO5 and SiO2. Sodium silicate and SiO2 nanoparticles were added to the coating to effectively reduce the size of micropores and increase its thickness, whereas SiO2 nanoparticles with superior physical properties could be directly deposited at the discharge channel, significantly increasing the coating's resistance to wear and corrosion. The coating with SiO2 nanoparticles provided the best overall performance, with the lowest corrosion rate and average friction coefficient (4.095×10-5 mm/a and 0.30, respectively).