Study on the Corrosion Resistance and Application of Nano-Y2O3/Al2O3-Modified Anchor Rod Coatings Based on Electrodeposition Method

In the past ten years, many coal mines have encountered the problem of a premature failure of anchor rod materials. Through field investigation and laboratory research, it was found that the premature failure of these bolt materials is mostly caused by mine water corrosion. In this paper, a Zn-Y2O3-Al2O3 composite coating was prepared by an electrodeposition method for the corrosion protection of underground anchors. Through the single-factor experiment method, the co-deposition process of Zn2+ nano-Y2O3 and nano-Al2O3 particles was studied. Microhardness was used as the index to determine the optimum preparation process for the composite coatings. Combined with FSEM and XRD tests, the results showed that the synergistic effect of nano-Y2O3 and nano-Al2O3 particles made the coating grain refined and reduced the coating defects. The hardness of the coating increased from 98.7 Hv to 347.9 Hv, and the hardness and wear resistance of the coating were improved. The hydrophobicity of the Zn-Y2O3-Al2O3 composite coating was improved, and its static contact angle was 93.28°. The corrosion resistance of the composite coating was studied through electrochemical impedance spectroscopy, the Tafel curve, corrosion morphology, and weight loss. Under the synergistic effect of nano-Y2O3 and nano-Al2O3 particles, the self-corrosion current density decreased from 4.21 × 10−4 A/cm2 to 1.06 × 10−5 A/cm2, which confirmed that the Zn-Y2O3-Al2O3 composite coating had better corrosion resistance and durability. After soaking in mine water for 63 days, the Zn-Y2O3-Al2O3 composite coating had no obvious shedding on the surface and was well preserved. The practical application results show that it has excellent corrosion resistance and durability. The Zn-Y2O3-Al2O3 nano-composite coating material has significant potential advantages in the field of corrosion resistance of underground anchor rods.