Electrolytic Composition on Wear Resistance and Corrosion Resistance of the Micro-arc Oxidation Coatings on TiC$lt;inf$gt;P$lt;/inf$gt;/Ti6Al4V Composites

Abstract

The ceramic coatings were prepared by micro-arc oxidation (MAO) on the TiC P /Ti6Al4V composites. The effects of NaOH, C 10 H 12 CaNa 2 N 2 O 8 ·4H 2 O and Na 2 SiO 3 additives in NaAlO 2 and NaH 2 PO 2 solutions on the microstructure, corrosion resistance and wear resistance of the ceramic coatings were investigated, respectively. The results showed that coatings prepared in NaH 2 PO 2 solution were composed of rutile and anatase TiO 2 , while coatings prepared in NaAlO 2 solution consisted of Al 2 TiO 5 , γ-Al 2 O 3 , rutile and anatase TiO 2 . The NaOH addition could increase reaction rate of the micro-arc oxidtion, and the hardness of the MAO coatings could be enhanced by the addition of NaAlO 2 and Na 2 SiO 3 . The thickness of the coatings formed in NaH 2 PO 2 solution is 2-3 times thicker than that of the coating formed in NaAlO 2 solution. The corrosion resistance of the coatings formed both in NaAlO 2 and NaH 2 PO 2 solutions, ranked from additives: Na 2 SiO 3 >C 10 H 12 CaNa 2 N 2 O 8 ·4H 2 O>NaOH. Wear resistance of the coatings formed in the NaAlO 2 solution ranked from the additives: Na 2 SiO 3 >NaOH>C 10 H 12 CaNa 2 N 2 O 8 ·4H 2 O, while the wear resistance formed by NaH 2 PO 2 solution ranked from additives: Na 2 SiO 3 >C 10 H 12 CaNa 2 N 2 O 8 ·4H 2 O>NaOH. After micro-arc oxidation, all of 第 4 期 罗军明, 等: 电解液组分对 TiC P /Ti6Al4V 复合材料微弧氧化膜耐蚀性及耐磨性影响 419 the corrosion resistant and wear resistance of the MAO coatings were higher than those of the untreated TiC P /Ti6Al4Vcomposites. The mciro-arc oxidation coatings formed in NaH 2 PO 2 +Na 2 SiO 3 solution showed the best corrosion resistance (about two orders of magnitude higher than that of the substrate) and better wear resistance.