Electrochemical and DFT studies of laser-alloyed TiB2/TiC/Al coatings on aluminium alloy

Microstructural and corrosion characteristic of laser-alloyed TiB2/TiC/Al composite coatings on 6082-T651 aluminium substrate were investigated. Density functional theory was used to study the chemical bonding of TiC and TiB2. The results confirmed a compact TiB2/TiC/Al-coating with low porosity, without any cracks and with good long-term stability against corrosion. Moreover, EIS and CP results confirmed enhanced corrosion resistance of laser-alloyed TiB2/TiC/Al coatings, with lower coating capacitance, increased polarization resistance and reduced corrosion current density compared to the Al 6082 substrate. Although, all the laser-alloyed coatings experienced pitting attack, the intensity of pitting attack was substantially reduced compared to the substrate material.