Chunlin HE
,
Changsheng LIU
,
Fengqin LI
,
Qingkui CAI
,
Zhiming SHI
,
Liqing CHEN
,
Jing BI
材料科学技术（英文）
The corrosion resistance of 2024 Al and SiC particle reinforced 2024 Al metal matrix composite (SiCp/2024Al MMC) in 3.5% NaCl solution was investigated with electrochemical method and immersion test, and the corrosion protection of sulfuric acid anodized coatings on both materials was evaluated by electrochemical impedance spectroscopy. The results showed that the SiCp/2024Al MMC is more susceptible to corrosion than its matrix alloy in 3.5% NaCl. For 2024Al, the anodized coating provides excellent corrosion resistance to 3.5% NaCl.The anodized coating on the SiCp/2024Al provides satisfactory corrosion protection, but it is not as effective as that for 2024Al because the structure of the anodized layer is affected by the SiC particulates.
关键词:
2024 Al
,
null
,
null
,
null
Chunlin HE
,
Changsheng LIU
,
Fengqin LI
,
Qingkui CAI Zhiming SHI
,
Liqing CHEN
,
Jing BI
材料科学技术（英文）
The influences of volume fraction and particle size of SiC particulate reinforcements on the corrosion characteristics of SiCp/2024 Al metal matrix composites in aerated 3.5 wt pct NaCl aqueous solution were investigated. The electrochemical behavior was investigated by potentiodynamic polarization and electrochemical impedance spectroscopy, the general corrosion behavior of the composites was studied further by immersion tests. The results showed that pitting susceptibility was about the same for the composites and the alloy. The corrosion potentials were also independent of SiC phase. The corrosion resistance for the composites decreased as the volume fraction increased or particle size decreased.
关键词:
SiCp/2024Al matrix composites
,
null
,
null
Yuan ZHANG
,
Yuan YUAN
,
Changsheng LIU
材料科学技术（英文）
A novel surface treatment method using 3-aminopropyltriethoxysilane (AMPTES), was developed to immobilize the fluorescein molecule on nano-HAP (nanometer hydroxyapatite) powders. By pretreating the nano-HAP powders surface with AMPTES, fluorescein, chosen on the basis of the chemical structure of the nano- HAP powders, could be bound to the nano-HAP powders surface. The chemical compositions of nano-HAP before and after being labeled were characterized by Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). The morphology, phase composition, and the fluorescence characteristics of the nano-HAP powders with and without staining were also investigated. The FTIR and XPS results revealed that fluorescein had been successfully immobilized on the surface of AMPTES-bound nano-HAP powders via the acylamide bond formation between the -COOH of fluorescein and the -NH2 of AMPTES. The labeled nano-HAP powders possessed strong fluorescent intensity with a little deviation from the maximum emission wavelength of fluorescein. But the morphology and phase composition had no obvious alteration. Under fluorescence microscopy, the labeled nano-HAP powders, even after 24 h cell incubation, exhibited strong fluorescence.
关键词:
Nano-HAP
,
null
,
null
,
null
