Zhaohua JIANG
,
Xuetong SUN
,
Yanping LI
,
Fuping WANG
,
Y
,
ong LÜ
材料科学技术（英）
Ceramic coatings were prepared on Ti-6Al-4V alloy using ac micro-arc oxidation (MAO) in silicate-hypophosphate solution. Growth regularity and formation mechanism of ceramic coatings were discussed. It was found that during the first stage the growth rate of coatings toward the external surface was larger than that toward substrate and then the coating began to grow mainly towards Ti alloy. When the total coating thickness reaches a certain value, it would no longer increase. In addition, the variations of the composition and microstructure of ceramic coatings according to the depositing time were also investigated with X-ray diffraction (XRD) and scanning electron microscope (SEM). The amount of rutile TiO2 gradually increased, whereas the amounts of the anatase TiO2 and amorphous phases first increased and then decreased slightly.
关键词:
Titanium alloy
,
null
,
null
,
null
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
Shigang XIN
,
Zhaohua JIANC
,
Fuping WANG
,
Xiaohong WU
,
Liancheng ZHAO
,
Tadao SHIMIZU
材料科学技术（英）
The microplasma oxidation process of LY 12 Al alloy in Na2SiO3-KOH-NaAlO2 system has been studied. The voltage-time curve of oxidation process is changed with the variation of current densities. The voltage breakdown and hardness of coating increase with increasing current density. The phase composition, morphologies, element and the distribution of ceramic coating are investigated by XRD, EPMA.
关键词:
