Indexed by:会议论文

Date of Publication:2014-01-01

Included Journals:CPCI-S、SCIE

Page Number:53-57

Key Words:Micro arc oxidation; Titania; Dual structure of micro/nano meter

Abstract:Micro arc oxidation (MAO) was made on pure Ti in three kinds of electrolytes of borate electrolyte of Li2B4O7, Na2B4O7 and K2B4O7. The morphology, structure and hydrophily of the coatings were investigated by SEM, XRD and contact angle measurement. The results showed that cortex-like slots formed on the surface of Ti in all three electrolytic solutions of borate, and coatings have dual structure of micro/nano porous in high resolution, there are nano pores distributing uniformly on the shoulder of micro slots. Analizing morphology change during the early time of MAO shows that the above dual micro/nano structure undergoes three stages: 1) uniform nano proes form; 2) dense of nano pores goes segregating; 3) nano pores at high dense place get connected, and transversal slots with micro scale are formed. The delicated structrue in different electrolyte is a little different: nano pores on shoulder of micro slots in Li2B4O7 electrolytic solution keeps the most complete and sharp, that in Na2B4O7 electrolytic solution are complete and smoother, and that in K2B4O7 electrolytic solution leaves few. The formation of micro slots is proposed due to dissolution of borate on TiO2 coatings at high temperature producing by micro arc. And the morphologies of nano pores is affected by kind of cations.