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This article uses the MAO - 100 -type self-developed micro-arc oxidation equipment , Si , Cu elements in varying amounts LY12, ZL104 Casting ZL108 , YL112 aluminum alloy as base material , research and analysis of the element content of the substrate Si, Cu and electrolytic fluid type and composition of cast aluminum alloy micro-arc oxidation process and micro-arc oxidation ceramic layer ; comparative test method , adjustment of the electrolyte composition and concentration , cast aluminum alloy containing Si, Cu element micro-arc oxidation processing, arcing early to improve the film growth rate , to reduce the current density for the research objectives , optimizing the electrolyte , development lower cast aluminum micro-arc oxidation energy consumption electrolyte ; using X-ray diffraction ( XRD ) analysis containing Si , Cu in the cast aluminum alloy in different electrolytes in micro-arc oxidation ceramic layer phase composition and its distribution pattern , using a scanning electron microscope (SEM) observation of the microscopic morphology of the ceramic layer . The results show that : the substrate Si , Cu presence of elements will increase the current density of micro-arc oxidation , while slowing the growth rate of the ceramic layer . Further study showed that the electrolyte in the silicate system , add the appropriate amount of sodium citrate, ammonium oxalate , can reduce the cast aluminum micro-arc oxidation current density and energy consumption and increase the growth rate of the ceramic layer . XRD analysis showed that the main phase of the micro-arc oxidation ceramic layer of γ-Al 2 O 3 , contains more the SiO 2 < / sub > amorphous phase , the phosphate system solution , the Si compounds the the SiO 2 < / sub > phase ; in silicate system solution , the compound of Si phase is 3Al 2 < / sub > O < sub > 3 · 2SiO 2 phase , two solutions system , contain a small amount of Cu 2 < / sub > O and CuAl of 4 < / sub > O < sub > 2 < / sub > phase .
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