Preparation And Properties Of SiC Particles Reinforced Micro-arc Oxidation Layer On Titanium Alloy

Titanium alloy got both low weight and high strength,which got prominent application prospects in marine engineering.However,metals for marine engineering required high hardness and corrosion resistance,which limited its application.In order to improve the defects of titanium alloy in marine engineering,micro-arc oxidation was used to treat titanium alloy substrate.By exploring the effect of electrical parameters and electrolyte on thickness,roughness,hardness,and corrosion current.Both electrical parameters and electrolyte were optimized.SiC particles of different granularity(400nm and 700nm)were added to the electrolyte.The effects of processsing time,concentration and granularity of SiC particle on the properties of MAO film were investigated to improve the hardness and corrosion resistance of titanium alloy.After the optimization experiment,thickness of MAO layer increased for above 5?m,the hardness raised for 100HV,the corrosion current reduced by an order of magnitude.SiC particles with 2 granularities both accelerated the ascent rate of forward voltage and reduced both forward and reverse current during the MAO process.Significantly,700nm SiC got more significant impact.Due to SiC particle,thickness of MAO coating increased for 10?pm,the hardness increased for 100HV,and the corrosion potential move 1V positively,the corrosion current reduced for nearly 50%,however the roughness increased for 0.3?m.When concentration of both granularities were lower than 2g/L,no significant difference was inestigated.When concentration of SiC was higher than 3g/L,400nm SiC particles got better optimized performance.Two granularities of particles both optimized the properties of MAO layer by increasing MAO processing time.Microcosmic structure was totally changed by nano particles.The micropore on the surface of the layer got larger,which amount was reduced.The surface morphology of the layer was obviously changed by the addition of nano SiC particles,which porosity reduced and corrosion resistance increased rapidly by impedance analysis.