Journal of Inorganic Materials ›› 2013, Vol. 28 ›› Issue (9): 961-966.DOI: 10.3724/SP.J.1077.2013.12734

• Research Paper • Previous Articles     Next Articles

Mechanism of Residual Stresses in Anodic Oxidized Film on Lead Substrate under Electric Field

LI Jian-Zhong, WEI Li-Hua, WANG Bo, SUN Xiu-Li, TIAN Yan-Wen   

  1. (School of Materials and Metallurgy, Northeastern University, Shenyang 110004, China)
  • Received:2012-12-04 Revised:2013-02-24 Online:2013-09-20 Published:2013-08-14
  • Contact: LI Jian-Zhong.
  • Supported by:

    National Natural Science Foundation of China (51004028); Special Fund for Basic Scientific Research of Central Colleges (N100402002)

Abstract: Mechanism of residual stresses generated in anodic oxidized film on lead alloy substrate was investigated using CrO3 solution with the influence of electric field. The stresses formation process, their relationship with surface morphology and structure of oxidation film were discussed in details based on the results of SEM, XRD and Raman tests. It is indicated that Cr2O72- and HCrO4- ions are absorbed on lead alloy surface in the initial formation process of oxidation film. Then PbCrO4 is formed on the interface of Cr2O72- and Pb. HCrO4- oxidizes Pb into PbO under electric field. At the same time, the stresses are generated gradually in the oxide film and increase quickly with current density increase. However, enhanced oxygen evolution promotes the formation of PbO or β-PbO2 with the increase oxidation time. Meanwhile, the growth of crystalline grain for lead oxides is believed to be mismatched with the developing inner stresses, releasing inner stresses, which lead to residual stresses decreasing in oxidation film. The film is cracked because stresses gradient increases remarkably in oxidized film due to the crystal lattice difference in different lead oxides.

Key words: electric field, lead alloy, anode, oxidation film, residual stresses

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