Formation process of ceramic coating prepared by MAO on Al alloys in silicate electrolyte
XIONG Ren - zhang, LEI Ting - quan, WANG Yong - kang, ZHEN Liang( Harbin Institute of Technology, Harbin 150001, China; Ningbo Surface Engineering Research Center, Ningbo 315103, China)
Microstructure and composition distribution of the ceramic coating prepared by micro - arc oxidation in silicate electrolytes at varied stages have been analyzed. The results show the growth of the early coating is determined only by the porous layer. The compact layer grows slowly in earlier stage and then quickens ceaselessly, the two layers finally grow in balance and the growth rate of the ceramic coating is obviously slower.