Effect of doped chromium oxide and graphene on microstructure and properties of tritium-blocking coatings on micro-arc alumina

In order to obtain high quality aluminium oxide tritium barrier coatings， micro-arc oxidation （MAO）technology was used to prepare micro-arc oxidation coatings on the surface of 1060 pure aluminium by doping Cr2O3 and graphene as additives in the electrolyte， using phosphate as the main electrolyte component. The surface morphology， elemental distribution， physical phase composition， thickness，hardness， abrasion and corrosion resistance of the micro-arc oxidation coatings were characterized by scanning electron microscope，X-ray diffractometer，eddy current thickness gauge，Vickers hardness tester， friction and wear tester， and electrochemical workstation. The results show that the surface morphology of the micro-arc oxidation coatings prepared by adding 3 g/L Cr2O3 and 1 g/L graphene into the electrolyte is more dense， and the proportion of α-Al2O3 and γ-Al2O3 in the coatings increases， with the thickness reaching 25.3 μm，the hardness reaching 763.01HV， and the average friction coefficient of 0.4781.At the same time，the self-corrosion potential is -0.185 V， and the self-corrosion current density is 1.095×10-9 A·cm-2.