Effect of CeO2 AdditionSon Interface Structure and Corrosion Resistance of Laser Additive Manufacturing on the Surface of Al Alloys

Abstract:

Ni60 alloy layers with different contends of rare-earth CeO₂ were prepared on the surface of 6063 aluminum alloy by using laser additive manufacturing. The effects of rare earth CeO₂ addition on microstructure, phase structure and corrosion resistance of bonding interface between Ni60-CeO₂ alloy layers and substrate were investigated by means of OM, XRD,SEM and electrochemical corrosion tester. The results show that on the surface morphology, 4%~5% CeO₂+Ni60 alloy layers have the best morphology, it is difficult to obtain a good alloy layer when the CeO₂ content of less than 3% . It is less surface pores, shedding and other defects when CeO₂ contents of 5% to 10% . On the cross-section morphology, the alloy layers prone to cracking at 0% to 2% CeO₂ content, the main defect is porosity when the content of 5% to 10%, 4% CeO₂ Ni60 alloy layer have no obvious pores and cracks, with a relatively good cross-section morphology. Adding 4% CeO₂ can improve the organizational structure of Ni60 alloy layer, promote grain refinement and compositions evenly distributed. Adding different contents of CeO₂ can improve aluminum surface morphology in Ni60 alloy layers, the preferred amount of rare earth CeO₂ is add 4% CeO₂. Electrochemical corrosion tests show that, the corrosion resistance of CeO₂ Ni60 alloy layer was 4.25 times as that of Ni60 alloy layer in 1mol/L H₂SO₄ solution. In 3.5% NaCl solution, the corrosion resistance of CeO₂ Ni60 alloy layer was 1.4 times as that of Ni60 alloy layer. In 1mol/L NaOH solution, the corrosion resistance of CeO₂ Ni60 alloy layer was 1.43 times as that of Ni60 alloy layer.