Passivation and Polishing Behavior of Chitosan in Low Pressure Chemical Mechanical Polishing of Aluminum

In order to meet the low⁃pressure polishing requirements of soft metals such as aluminum, passivator is often introduced to enhance the slow release of polishing fluid and improve the polishing quality. However, the traditional strong passivator has some problems, such as high price, strong corrosion inhibition effect and environmental pollution. In this paper, carboxymethyl chitosan (CMCS) was used instead of traditional strong passivating agent to achieve a balance between weak corrosion inhibition and low⁃pressure polishing. The effect of CMCS on the polishing effect of aluminum under weak alkaline conditions was studied by static etching and chemical mechanical polishing (CMP) experiments. The effect of CMCS on the stability of silicon sol was studied by Zeta potential and particle size analysis. The experimental results show that the addition of CMCS can effectively reduce the chemical corrosion on the aluminum surface. At the same time, the 0.05% CMCS can also improve the dispersion of silica sol and prevent the erosion of aluminum surface caused by abrasive aggregation. XPS, electrochemistry and other experimental characterization methods were used to study the corrosion inhibition effect of CMCS on the surface of aluminum sheet, and it was verified that CMCS can form nano adsorption layer on the surface of aluminum sheet and play the role of interfacial corrosion inhibitor. © 2023 Cailiao Daobaoshe/ Materials Review. All rights reserved.