王艳秋
,
吴昆
,
郑明毅
金属学报
采用微弧氧化表面处理技术在SiCw/AZ91镁基复合材料表面制备保护性涂层。通过与AZ91镁合金对比，研究镁基复合材料的微弧氧化行为及其形貌特征，并采用电化学方法评价了微弧氧化涂层的耐腐蚀性能。结果表明，由于SiC晶须的加入影响了阻挡层的形成，使复合材料的微弧氧化行为不同于基体合金。与合金相比，复合材料在恒电流模式下进行微弧氧化的过程中电压随时间的演变趋势不够理想，而且在相同条件下镁基复合材料的起弧时间比合金要长，导致复合材料在火花放电之前发生腐蚀。SiCw/AZ91镁基复合材料在微弧氧化过程中可能会出现烧蚀现象。虽然SiC晶须会影响复合材料表面涂层的形成，微弧氧化处理仍然能够增强镁基复合材料的耐腐蚀性能，在提高其腐蚀电位的同时降低腐蚀电流。当采用恒压模式制备涂层时，涂层耐腐蚀性能随电压的提高而增强。
关键词:
镁基复合材料
,
Microarc oxidation
,
Coatings
,
Corrosion resistance
Fu LIU
,
Fuping WANG
,
Tadao Shimizu
,
Kaoru Igarashi
,
Liancheng ZHAO
材料科学技术（英）
The ceramic coating was formed by using microarc oxidation (MAO) in the electrolytic solution of β-Glycerophosphate sodium salt pentahydrate (β-GP) and calcium acetate (CA). The microstructure, phase structure and phase composition were investigated with scanning electron microscopy (SEM), atomic force microscope (AFM), energy dispersive X-ray microanalyser (EDX), X-ray photoelectron spectroscopy (XPS), electron probe micro analyzer (EPMA) and X-ray diffraction (XRD). Investigation of the chemical composition of the coating with EDX revealed that Ca and P of high concentration existed in oxide films. XRD patterns indicated that the oxide film was composed of only anatase at low voltage discharge, and that rutile peaks appear in addition to anatase peak with increasing MAO voltage. Despite the existence of Ca and P, compounds concerning Ca and P were not detected in the oxide film.
关键词:
Microarc oxidation
,
null
,
null
Wenbin XUE
,
Chao WANG
,
Zhiwei DENG
,
Ruyi CHEN
,
Tonghe ZHANG
材料科学技术（英）
Dense ceramic oxide coatings of about 50 μm may be prepared on Ti-6Al-4V alloy surface by alternating-current microarc oxidation in aluminate and silicate solutions, respectively. Their phase constituent and microstructure were characterized using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results show that the electrolytic ions have incorporated into the interior of the coatings. The coating formed in aluminate solution is composed of the rutile TiO2 and TiAl2O5 phases rather than the rutile, anatase and amorphous SiO2 phases for the coating formed in silicate solution. However, TiAl¬2O5 content in the outer layer of the two coatings is much higher than in the inner layer. It is suggested that all these oxides may result from a rapid solidification of the molten coating in the microarc discharge zone.
关键词:
Microarc oxidation
,
null
,
null
