电流密度对铝合金微弧氧化膜物理化学特性的影响  

Effect of current density on physical and chemical properties of microarc oxidation coatings of aluminium alloy

作　　者：吴汉华[1,2] 汪剑波[2] 龙北玉[1] 吕宪义[2] 龙北红[2] 金曾孙[2] 白亦真[3] 毕冬梅[1] 

机构地区：[1]吉林大学物理学院,长春130023 [2]吉林大学超硬材料国家重点实验室,长春130012 [3]大连理工大学物理系,三束材料改性国家重点实验室,大连116024

出　　处：《物理学报》2005年第12期5743-5749,共7页Acta Physica Sinica

摘　　要：利用微弧氧化(MAO)技术,在LYl2铝合金上沉积了显微硬度达42.14GPa的超硬陶瓷膜.采用x射线衍射仪和显微硬度计研究了阳极电流密度ja和阴极、阳极电流密度比jc/ja对MAO膜相构成和力学特性的影响.此外,利用扫描电子显微镜和恒电位仪分别对膜的微结构和抗点腐蚀特性进行了分析.结果表明,高ja制备的膜主要含α_Al2O3相,低ja制备的膜主要含γ_Al2O3相.显微硬度测试表明,这类膜有较高的硬度,但以ja=15A/dm2和jc/ja=0.7制备的陶瓷膜硬度最高.抗点腐蚀测试表明,jc/ja对陶瓷膜的微结构有很强的影响.Ultra-hard ceramic coatings with microhardness of 42.14 GPa have been synthesized on the Al alloy substrate by microarc oxidation （MAO） technique. The effects of anodic current density ja and the ratio of cathodic to anodic current density Jc/Ja on the mechanical property and phase composition of MAO coatings have been studied by microhardness test and x-ray diffraction, respectively. In addition, the microstructure and corrosion resistance of the coatings were analyzed by scanning electron microscopy and pitting corrosion test, respectively. The results show that the samples prepared at high anodic current density consist mainly of α-Al2O3 , while the samples fabricated at low anodic current density are composed almost entirely of γ-Al2O3 . Microhardness test shows that these kinds of samples have high hardness, and the microhardness of the coating prepared at ja = 15 A/dm^2 and jc/jn = 0.7 is the highest of all coatings prepared. Pitting corrosion test shows that the structure of coatings is strongly influenced by the variation in Jc/Ja.

关 键 词：微弧氧化 显微硬度 电流密度 抗点腐蚀 

分 类 号：TG174.44[金属学及工艺—金属表面处理]