Open AccessEffects of cathodic voltage pulse duty cycle on characteristics of microarc oxidation coatings of titanium alloy
Author(s) -
Tang Yuan-Guang,
Huibin Wu,
Chen Hong,
Genyu Chen,
Sang Yong,
Bai Yi-Zhen
Publication year - 2009
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.58.4840
Subject(s) - materials science , rutile , anatase , indentation hardness , duty cycle , coating , cathodic protection , titanium , titanium alloy , alloy , anode , voltage , pulsed dc , metallurgy , phase (matter) , constant voltage , composite material , microstructure , chemical engineering , electrode , thin film , nanotechnology , electrical engineering , chemistry , sputter deposition , engineering , sputtering , biochemistry , photocatalysis , catalysis , organic chemistry
Under the condition of keeping the bipolar pulse voltage constant, the effect of cathodic pulse voltage duty cycle dc on characteristics of microarc oxidation coatings of titanium alloy have been studied by using a multifunction microarc oxidation power supply. Experimental results show that the variations of cathodic and anodic currents with treatment time show obviously several stages, and the beginning and ending time of various stages are closely related to dc. The coating consists mainly of rutile and anatase phases, and there is a sudden change in the rutile phase content at dc=50%. The thickness, morphology and microhardness of the coating strongly depend on dc change. The microhardness valucs of the coatings prepared at dc=50% and dc=70% are the minimum 4.96 GPa and the highest 6.1 GPa, respectively. In general, the MAO coatings prepared in the range of 65%≤dc≤80% have higher growth rate and quality.