电参数对纯铝微弧氧化膜结构及性能的影响

发布时间：2024-07-31

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摘要：: Oxidation film of aluminum is prepared in electrolytes with Na_2SiO_3 by
micro-arc oxidation meth od. The effect of current density,duty ratio
and frequency on structure and properties of microarc oxidation coating
on aluminum is studied by XRD, SEM, micro-hardness test, thickness test
and dropping corrosion experiment. The results show that the coatingrs
hardness, surface roughness and the content of alpha-Al_2O_3 and
gamma-Al_2O_3 increase with the increase of current density. The
thickness and corrosion-resistance increase first and then decrease with
the increase of current density. With the increase of duty ratio, the
ceramic coatingrs thickness, hardness and surface roughness increase.
When the duty ratio is less than 30%, the corrosion time increase with
the increase of the duty ratio. But when the duty ratio is more than
30%, the corrosion time is decrease. When the duty ratio is 30%, the
ceramic coating has best corrosion resistance. The influence of
frequency on the coating′s hardness and roughness is little. When the
frequency is 5000Hz, the coating has best thickness and corrosion
resistance.