scholarly journals Corrosion Behavior of Zinc-Graphite Metal Matrix Composite in 1 M of HCl

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
M. A. Afifi

This paper is aimed at investigating the corrosion behavior of Pure and Zinc-graphite particles with percentage of 1, 3, and 5%, respectively. The composites were fabricated by powder metallurgy method. Corrosion tests were performed according to ASTM standard. Corrosion rate was calculated and it is found that in all cases the corrosion rate was decreasing with the increase in exposure time. Meanwhile, the microstructure of composites was imaged and analyzed using optical microscope and scanning electron microscope. It is observed that the best corrosion resistance was zinc with 1% Graphite while Zinc with 3% and 5% Graphite composites did not enhance the corrosion resistance comparing to pure Zinc.

2016 ◽  
Vol 849 ◽  
pp. 196-202
Author(s):  
Yang Fei ◽  
Xiao Bo Zhang ◽  
Zhi Xin Ba ◽  
Zhang Zhong Wang

In order to study the effect of solution temperature on corrosion resistance of Mg alloy for biomedical applications, microstructure and corrosion behavior of Mg-2.25Nd-0.11Zn-0.43Zr (NZ20K) alloy solution treated at different temperatures were investigated by using a scanning electron microscope (SEM) equipped with an electron dispersive spectroscope (EDS), electrochemical and mass loss tests. The results show that the grains grow and precipitations decreases with increasing the solution temperature. The corrosion rate decreases firstly and then increases with increasing solution temperature, and the best corrosion resistance of the NZ20K alloy is obtained at the temperature of 540 °C.


2014 ◽  
Vol 618 ◽  
pp. 247-251
Author(s):  
Chuan Qi Fu ◽  
Fan Yong ◽  
Qing Le Zhang

In order to improve the corrosion resistance of electro-less Ni-P-PTFE composite coating, electro-less Ni-P-PTFE composite coatings were prepared on 45# carbon steels specimen with addition of rare element cerium (Ce). Surface morphology of the coatings was observed by scanning electron microscope (SEM). Effect of cerium concentration on PTFE content of the coatings was investigated. The results indicated that properly added cerium into the bath increases the PTFE content of the coatings, decrease the corrosion rate, made the corrosion resistance improved of the coatings. And effect of cerium concentration on corrosion resistance of the composite coatings was evaluated by immersion test with 3.5% NaCl and 5% NaOH solutions respectively. With the rare element cerium concentration exceeding, the corrosion rate gradually increase. At the cerium concentration was 0.01 g.L-1, the corrosion rate of coating in the solutions were lowest, at 0.00186 mg·cm-2·h-1and 0.00109 mg·cm-2· h-1. But with the cerium concentration go on increasing, the corrosion resistance of the coatings then decreases.


2009 ◽  
Vol 68 ◽  
pp. 133-144 ◽  
Author(s):  
Jesús Lugo-Quintal ◽  
Luis Díaz-Ballote ◽  
Lucien Veleva ◽  
Antonio Contreras-Cuevas

The corrosion behavior in NaCl solutions at different pH values of Al-Cu-Li/SiCp and Al-Cu/SiCp composites fabricated by co-spraying technique was studied. The corrosion behavior of the composites was also compared with the corrosion behavior of pure aluminum. Corrosion potential measurements and potentiodynamic polarization were used to elucidate the corrosion behavior of the composites. In addition the microstructure and morphology of the composites were studied through X-ray diffraction (XRD) and scanning electron microscope (SEM). It was found that the corrosion rate of Al-Cu-Li/SiCp and Al-Cu/SiCp composites was higher than corrosion rate of pure aluminum for all NaCl solutions tested. Both composites and pure aluminum showed the typical “U” behavior of the corrosion rate as a function of pH. The addition of lithium had little effect on the corrosion behavior of the composites.


2014 ◽  
Vol 937 ◽  
pp. 168-171 ◽  
Author(s):  
Zhi Chao Qiu ◽  
Xiang Liu ◽  
Na Zhang

Corrosion experiments were applied for 13Cr steel. Through the experiments, the corrosion rate of 13Cr steel in different temperature was tested. The corrosion rate of 13Cr steel was increased with the increase of temperature. Moreover X-ray diffraction analysis and scanning electron microscope analysis were applied to understand the corrosion behavior of 13Cr in micro-scale.


2017 ◽  
Vol 729 ◽  
pp. 40-45 ◽  
Author(s):  
Wei Bing Kong ◽  
Xin Xin Li ◽  
Xin Ping Hu

AlMg5Si1-xRE (x=0%, 0.9%) alloys were prepared by resistance melting method, and the phases of alloy were analyzed by X-ray diffraction (XRD) and scanning electron microscope (SEM). The effects of RE (rare earth) on the corrosion resistance of AlMg5Si1 alloy immersed in seawater in different time were investigated by potential measurements and electrochemical impedance spectroscopy. The results showed that the strengthening phase β (Mg2Si) was short rod like and dispersing distributed in α (Al) in the AlMg5Si1 alloy after adding 0.9% RE. Under the conditions of seawater immersion, the corrosion rate of the AlMg5Si1RE0.9 alloy was less than that of AlMg5Si1 alloy, and the corrosion rate of AlMg5Si1RE0.9 immersed 12h in seawater was the slowest, 5.7 uA·cm-2. The improved corrosion resistance is due to the changes in microstructure and corrosion products.


Author(s):  
J. Alias

Much research on magnesium (Mg) emphasises creating good corrosion resistance of magnesium, due to its high reactivity in most environments. In this study, powder metallurgy (PM) technique is used to produce Mg samples with a variation of aluminium (Al) composition. The effect of aluminium composition on the microstructure development, including the phase analysis was characterised by optical microscope (OM), scanning electron microscopy (SEM) and x-ray diffraction (XRD). The mechanical property of Mg sample was performed through Vickers microhardness. The results showed that the addition of aluminium in the synthesised Mg sample formed distribution of Al-rich phases of Mg17Al12, with 50 wt.% of aluminium content in the Mg sample exhibited larger fraction and distribution of Al-rich phases as compared to the 20 wt.% and 10 wt.% of aluminium content. The microhardness values were also increased at 20 wt.% and 50 wt.% of aluminium content, comparable to the standard microhardness value of the annealed Mg. A similar trend in corrosion resistance of the Mg immersed in 3.5 wt.% NaCl solution was observed. The corrosion behaviour was evaluated based on potentiodynamic polarisation behaviour. The corrosion current density, icorr, is observed to decrease with the increase of Al composition in the Mg sample, corresponding to the increase in corrosion resistance due to the formation of aluminium oxide layer on the Al-rich surface that acted as the corrosion barrier. Overall, the inclusion of aluminium in this study demonstrates the promising development of high corrosion resistant Mg alloys.


Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4045
Author(s):  
Rafał Mech ◽  
Jolanta Gąsiorek ◽  
Amadeusz Łaszcz ◽  
Bartosz Babiarczuk

The paper presents a comparison of the results of the corrosion resistance for three Fe-B-Co-Si-based newly developed alloys with the addition of Nb and V. The corrosion performance differences and microstructure variations were systematically studied using scanning electron microscope, electric corrosion equipment, X-ray diffractometer, and differential calorimeter. It has been shown that each alloying addition increased the corrosion resistance. The highest corrosion resistance obtained by potentiodynamic polarization was found for the alloy with both Nb and V addons (Fe57Co10B20Si5Nb4V4) and lowest in the case of the basic four-element Fe62Co15B14Si9 material. This shows that the proper choice of additions is of significant influence on the final performance of the alloy and allows tailoring of the material for specific applications.


2011 ◽  
Vol 23 (7) ◽  
pp. 526-534 ◽  
Author(s):  
Yang Wang ◽  
Boming Zhang ◽  
Jinrui Ye

Hybrid nanocomposites were successfully prepared by the incorporation of polyethersulfone (PES) and organoclay into epoxy resin. They had higher fracture toughness than the prepared PES/epoxy blend and organoclay/epoxy nanocomposites. The microstructures of the hybrid nanocomposites were studied. They were comprised of homogeneous PES/epoxy semi-interpenetrating network (semi-IPN) matrices and organoclay micro-agglomerates made up of tactoid-like regions composed of ordered exfoliated organoclay with various orientations. The former was confirmed with dynamic mechanical analysis, scanning electron microscopy and transmission electron microscopy, while the latter was successfully observed with X-ray diffraction measurements, optical microscope, scanning electron microscope and transmission electron microscope. The improvement of their fracture toughness was due to the synergistic toughening effect of the PES and the organoclay and related to their microstructures.


2012 ◽  
Vol 457-458 ◽  
pp. 270-273
Author(s):  
Yi You Tu ◽  
Guo Zhong Li

Effect of superheat and initial rolling temperature on the morphology and distribution of sulfide in non quenched and tempered free cutting steel 30MnVS has been studied by optical microscope and scanning electron microscope. Results show that proper superheat and initial rolling temperature can turn rod-shaped sulfide into massive or globular sulfide,to alleviate sulfide segregation and pro-eutectoid ferrite distribution along the boundary of pearlite clusters in 30MnVS , increase the intragranular ferrite content and optimize the structure of continuous casting slab.


2016 ◽  
Vol 850 ◽  
pp. 101-106 ◽  
Author(s):  
Shu Mei Li ◽  
Jian Jun Yang ◽  
Wei Dong Zhang ◽  
August Chang ◽  
Cai Xia Zhang ◽  
...  

Premature fracture of an axle under torsional load occurred after a tracked military tank had experienced field testing for only 80 kilometers. Visual metallographic examinations were performed with optical microscope (OM) and scanning electron microscope (SEM). The investigation demonstrates that the premature fracture is caused by metallurgical problems inside the axle where the primary and secondary cracks originate, propagate, and eventually result in final catastrophic rupture through torsional fatigue. The failure mechanism is summarized and improvement of the fatigue lifetime for the axle is recommended.


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