【摘要】 为了消除铝阳极氧化膜高耐蚀封孔液中六价铬对环境的污染,对LY12铝合金阳极氧化膜分别进行勃姆石溶胶封孔、硝酸铈溶液封孔、Ni2+-Co2+盐高温水解封孔、Co2+-三乙醇胺常温封孔和Ni2+-F--Zn2+盐常温封孔,测试无铬封孔膜的膜重,磷铬酸酸浸失重,酸性点滴液变色时间,并进行染色试验,然后与沸水封孔、重铬酸钠封孔工艺做对比。结果表明,无铬封孔方法中勃姆石溶胶法制得的封孔膜的点滴液变色时间最长为36min,酸浸失重量最小为2.45g/m2,且封孔膜染色后膜颜色最浅;极化曲线和电化学阻抗谱显示封孔膜的耐3.5%NaCl腐蚀性由强到弱依次为:勃姆石溶胶封孔膜>重铬酸钠封孔膜>Ni2+-F--Zn2+封孔膜>沸水封孔膜>Ni2+-Co2+封孔膜>硝酸铈封孔膜>Co2+-三乙醇胺封孔膜,且盐水中溶胶封孔膜的腐蚀电流密度比重铬酸钠封孔膜的低2个数量级。更多还原

【Abstract】 Anodic oxidation coatingB of Al alloys were sealed by Cr-free Ni2-Co2 high tem-perature sealing,Co2-N(CH2CHjOH)3 room temperature seal-ing,Ni2+-F--Zn2+salt room temperature sealing,cerium nitrate sealing,and sol-gel sealing so as to eliminate the pollution to en-vironment of Cr6 ions in conventional sealing baths.The proper-ties of the sealing films were compared to that of boiling water sealing film and sodium dichromate sealing film using surface density test,weight loss test after being immersed in phosphoric-chromic acid solution,acidic dropping test.Results indicated that the sol-gel sealing film had the longest tarnishing time of 36 min and smallest weight loss of 24.5 mg/dm2 after immersion in phosphoric-chromic acid solution.The polarization curve and electrochemical impedance spectra showed that the corrosion re-sistance of various sealing films could be ranked as:sol-gel seal-ing film > sodium dichromate sealing film > Ni2+-F--Zn2 sealing film > boiling sealing film > Ni2+-Co2+ sealing film > cerium nitrate sealing film > Co2+-N(CH2 CH2 OH),sealing film.And the corrosion current density of the sol-gel sealing film was lower than that of sodium dichromate sealing film by about 2 orders of magnitude.更多还原