摘要
Micro plasma oxidation(MPO) has recently been investigated as a novel, rapid and effective means to provide modified surfaces with improved properties of load bearing and wear resistance on light alloys particularly aluminum alloys. MPO is a multifactor-controlled process, these factors must be controlled to produce high quality coatings. The main research emphasis in MPO coating development over the past years seems to be the attainment of higher hardness levels and thick coatings. The porosity of MPO coating is the most complex phenomenon affecting the distribution, levels and the measurements of the hardness; and it is controlled by suitable selection of important parameters such as the electrical conditions. Ceramics coatings were synthesized on Al substrate by MPO to examine the effects of adding a cathodic phase alternated with anodic-cathodic current on the porosity and hardness characteristics of coatings by X-ray diffraction(XRD), scanning electron microscopy(SEM), and microhardness tester. The coatings produced by the combined mode are more dense and less porous than that by the anodic-cathodic mode. (Microhardness) test shows that the coatings produced by the combined mode exhibit both the highest hardness, and less reduction percentage in hardness with increasing the coatings thickness. These improvements become more significant for the polished and thicker coatings.
Micro plasma oxidation (MPO) has recently been investigated as a novel, rapidand effective means to provide modified surfaces with improved properties of load bearing and wearresistance on light alloys particularly aluminum alloys. MPO is a multifactor-controlled process,these factors must be controlled to produce high quality coatings. The main research emphasis in MPOcoating development over the past years seems to be the attainment of higher hardness levels andthick coatings. The porosity of MPO coating is the most complex phenomenon affecting thedistribution, levels and the measurements of the hardness; and it is controlled by suitableselection of important parameters such as the electrical conditions. Ceramics coatings weresynthesized on Al substrate by MPO to examine the effects of adding a cathodic phase alternated withanodic-cathodic current on the porosity and hardness characteristics of coatings by X-raydiffraction (XRD), scanning electron microscopy(SEM), and microhardness tester. The coatingsproduced by the combined mode are more dense and less porous than that by the anodic-cathodic mode.Microhardness test shows that the coatings produced by the combined mode exhibit both the highesthardness, and less reduction percentage in hardness with increasing the coatings thickness. Theseimprovements become more significant for the polished and thicker coatings.
出处
《中国有色金属学会会刊：英文版》
EI
CSCD
2005年第1期113-118,共6页
Transactions of Nonferrous Metals Society of China
关键词
微观等离子体氧化
铝合金
硬度
多孔材料
micro plasma oxidation(MPO)
aluminum alloys
hardness
porosity
