Authors: Chun Yu Wang, Gao Hui Wu, Peng Chao Kang, Yun He Zhang, Zi Yang Xiu, Guo Qin Chen
Abstract: Improved corrosion resistance of carbon fiber reinforced aluminum (Cf/Al) matrix
composites can be achieved by applying appropriate coatings, and the electroless plating
nickel-phosphor (Ni-P) coatings on the Cf/Al composites was provided in this paper. It has been
founded that the pretreatment with zinc dipping solution for the electroless plating Ni-P can be
approved perfect coatings on the Cf/Al composites. The EDS lines scanning results that the length
of Ni-P coating is about 12 +m. In zinc dipping bath, matrix Al alloy surface could catch hold of
action points for depositing Ni-P with substitution reaction, however, carbon fibers surface only
have adsorption action points from zinc dipping bath, then, Ni-P alloys could deposit on the Al
surface or carbon fibers. The uncoated and coated composites samples immersed in 3.5 wt % NaCl
solution to contrast. The pitting corrosion behavior of the uncoated composites destroyed materials,
therefore, the coated sample appeared pitting only on the surface. The corrosion resistance
mechanisms of Ni-P coatings came from inhabiting the formation of the classical galvanic corrosion,
additionally, the Ni-P coating was amorphous structure, there was not grains boundary which is
sensitive for the corrosion reaction, so the corrosion resistant of Cf/Al composites were improved.
1675
Authors: Rui Na Ma, Sha Sha Jin, Hong Yun Li
Abstract: The static constant corrosion tests on Fe-B eutectic alloy are investigated in liquid zinc at 500°C. The systematic observation and research of the corrosion layer are performed using SEM, TEM, XRD. The results show that corrosion resistance of Fe-B eutectic alloy in liquid zinc is perfect. Corrosion products are Fe3B and FeZn7. The corrosion layer is regular, the structure of which is hollow dendritic skeleton and the thickness of which increases with the corrosion time extending. Corrosion process is that the interdiffusion of ferro and zinc atomic results in corrosion layer formation and the corrosion layer ruptures and dissolves under the action of thermal stress and impact stress of liquid zinc. The process repeating leads to the failure of the matrix eventually.
805
Authors: Xiao Ming Cao, Peng Fei Yin, Rui Na Ma
Abstract: Fe-B alloys with different boron contents were dipped into a pure molten zinc bath to investigate their anti-corrosion property. Scanning electron microscope (SEM) and energy dispersive spectrum(EDS) were used to detect the corrosion products. It is found that the corrosion mechanism of α phase is corrosion and dissolution ,while the Fe2B phase is crack mechanism because of its brittleness and excellent corrosion resistance.The Fe2B phase in eutectic structure can protect the matrix from molten zinc and restrict the reaction of Fe-Zn. With the increase of boron content, the corrosion resistance performance of the alloys improves gradually.
3051
Authors: Feng Jun Lang, Ying Ma, Jian Rong Liu, Xian Qiu Huang, Mou Cheng Li
Abstract: The influence of passivation on pitting corrosion of 316L stainless steel in concentrated seawater was investigated by using cyclic anodic polarization and critical pitting temperature. The results indicated that the pitting potential of passivated specimen was higher than that of matrix specimen in concentrated seawater at 25°C and 85°C. Critical pitting temperature value of passivated specimen was 56°C, which was much higher than 11°C for matrix specimen. Pitting corrosion occurred in the formed pit of passivated specimen, and metastable pit, lacy cover and new pit were observed in pit morphology.
127
Authors: Yan Bo Wu, Xiao Xi Wang, Ting Lou, Tie Ben Song
Abstract: SnSO4 and TiOSO4 were chosen in this paper as the main salts for preparing composite chemical conversion coating on aluminum alloy. The scope of this paper is to find out the optimal experiment process, the performance of Ti-Sn composite chemical conversion coating and tentative to analysis the microstructure of this chemical conversion coating. The optimal conditions of the concentration ratio of TiOSO4 and SnSO4 was 0.4g/L, 0.4g/L, KMnO4 1.0g/L, NaF 1.0g/L, reaction temperature 50°C、reaction time was 3min. And then different methods were used to study the performance and microstructure of the conversion coating.
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