Structure, phase transformation and corrosion resistance of CrAlN/CN  composite multilayer films in NaCl aqueous solution

The TiC/Ti(CN)/TiN multilayer coatings were deposited on 42CrMo steel by chemical vapor deposition (CVD) method. The fracture morphology,structure,microhardness and adhesion of the coatings were analyzed. The immersion test in simulant solution with H2S,CO2 at 100°C and electrochemistry test in 20wt% H2SO4 at room temperture were applied to investigate the corrosion resistance of the multilayer films.The results reveal that the multilayer coatings can offer 42CrMo steel higher corrosion resistance,especially the immersion corrosion test.The corrosion rate of the samples coated with CVD multilayer films is reduced more 70 times than that of the uncoated and samples by quenching-polishing-quenching (QPQ) treat.

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Antibacterial TiCu/TiCuN Multilayer Films with Good Corrosion Resistance Deposited by Axial Magnetic Field-Enhanced Arc Ion Plating

ACS Applied Materials & Interfaces ◽

10.1021/acsami.8b14038 ◽

2018 ◽

Vol 11 (1) ◽

pp. 125-136 ◽

Cited By ~ 14

Author(s):

Cong Peng ◽

Yanhui Zhao ◽

Shujing Jin ◽

JingRen Wang ◽

Rui Liu ◽

...

Keyword(s):

Magnetic Field ◽

Corrosion Resistance ◽

Axial Magnetic Field ◽

Multilayer Films ◽

Arc Ion Plating ◽

Ion Plating ◽

Good Corrosion Resistance

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Accelerated Short-Term Techniques to Evaluate Corrosion in TiC Reinforced AA6063 Composites

JOURNAL OF ADVANCES IN CHEMISTRY ◽

10.24297/jac.v13i10.5898 ◽

2017 ◽

Vol 13 (10) ◽

pp. 5905-5913

Author(s):

S. Saravanan ◽

P.Senthil Kumar ◽

T. Palanisamy ◽

M. Ravichandran ◽

V. Anandakrishnan ◽

...

Keyword(s):

Aqueous Solution ◽

Corrosion Resistance ◽

Corrosion Rate ◽

Room Temperature ◽

Stir Casting ◽

Short Term ◽

Accelerated Corrosion ◽

Weight Percentage ◽

The Poor ◽

Accelerated Corrosion Tests

AA6063-TiC composites have several weight percentages up to 9 wt. % were fabricated by using stir casting route method. The effects of the weight percentage of TiC particles on the microstructures and corrosion behavior of AA6063-TiC composites were studied. The results revealed that the AA6063-TiC composites exhibited higher density than the AA6063 matrix. The accelerated corrosion tests of AA6063-TiC composites in 3.5 wt. % NaCl aqueous solution at room temperature, the AA6063-TiC composites have better corrosion resistance than the AA6063 matrix. Increasing the weight percentage of the TiC particles to reduces the corrosion rate of the AA6063-TiC composites. In this process corrosion rate of 0.4402 mm/year for AA6063 matrix, 0.3891 mm/year for 3 wt. % , 0.3568 mm/year for 6 wt. % and 0.3062 mm/year for 9 wt. % of TiC particles respectively. The poor corrosion resistance of the composites can be attributed to the galvanic effects between the AA6063 matrix and TiC reinforcement.

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Corrosion Resistance Evaluation of a Stainless-Steel Brazed Joint in HCl Solution

Materials Science Forum ◽

10.4028/www.scientific.net/msf.1016.997 ◽

2021 ◽

Vol 1016 ◽

pp. 997-1002

Author(s):

Hikaru Nagata ◽

Masa Ono ◽

Yasuyuki Miyazawa ◽

Yuji Hayashi ◽

Yoshio Bizen

Keyword(s):

Aqueous Solution ◽

Stainless Steel ◽

Corrosion Resistance ◽

Base Metal ◽

Corrosion Behavior ◽

Anodic Polarization ◽

Filler Metal ◽

Brazed Joint ◽

In Situ Observations

To clarify the effect of the acid solution type on corrosion resistance, the corrosion behavior of stainless steel brazed joints in HCl aqueous solution was evaluated through electrochemical measurements. Anodic polarization curves of a ferritic stainless-steel base metal, Ni-based brazing filler metals, and a brazed joint were recorded. In addition, in situ observations were conducted to observe the corrosion behavior of each structure of the brazed joint. Corrosion potentials of the brazing filler metal were lower than that of the base metal. In situ observations of the brazed joint revealed the order of corrosion in aqueous hydrochloric acid. According to the electrochemical measurements, under an actual corrosive environment, the brazing filler metal can function as an anode and selectively corrode. In addition, the anodic polarization curve of the brazed joint showed values between those of the polarization curves of the brazing filler metal and the base metal, indicating that the corrosion resistance could be electrochemically evaluated in HCl aqueous solution.

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Effect of Al Content in the Mg-Based Alloys on the Composition and Corrosion Resistance of Composite Hydroxide Films Formed by Steam Coating

Materials ◽

10.3390/ma12071188 ◽

2019 ◽

Vol 12 (7) ◽

pp. 1188 ◽

Cited By ~ 1

Author(s):

Takahiro Ishizaki ◽

Tomohiro Miyashita ◽

Momo Inamura ◽

Yuma Nagashima ◽

Ai Serizawa

Keyword(s):

Aqueous Solution ◽

Corrosion Resistance ◽

Treatment Time ◽

Mg Alloys ◽

Mg Alloy ◽

Potential Range ◽

Protective Film ◽

Al Content ◽

Passive Behavior ◽

Superior Corrosion Resistance

Mg alloys are expected to be used in fields of the transportation industry because of their lightweight property, however, they show low corrosion resistance. To improve the corrosion resistance, preparation of the protective film on Mg alloys is essential. In this study, composite hydroxide films were prepared on three types of Mg alloys with different aluminum contents—that is, AZ31, AZ61, and AZ91D—by steam coating to investigate the relationship between the Mg-Al layered double hydroxide (LDH) content in the film and the Al content in the Mg alloys. Scanning electron microscopy (SEM) observation demonstrated that films were formed densely on all Mg alloy surfaces. X-ray diffraction (XRD) analyses revealed that all films prepared on AZ61 and AZ91D were composed of Mg(OH)2, AlOOH, and Mg-Al LDH, while the film containing Mg(OH)2 and Mg-Al LDH were formed only on AZ31. The Mg-Al LDH content in the film prepared on AZ61 was relatively higher than those prepared on AZ31 and AZ91D. The content of AlOOH in the film increased with an increase in the Al content in the Mg alloys. The film thickness changed depending on the treatment time and type of Mg alloy. Polarization curve measurements in 5 mass% NaCl solution demonstrated that the film prepared on the AZ61 showed complete passive behavior within the potential range of −1.0 to −0.64 V. In addition, immersion tests in 5 mass% NaCl aqueous solution for 480 h demonstrated that the film on the AZ61 had superior durability against 5 mass% NaCl aqueous solution. These results indicated that the film on the AZ61 had the most superior corrosion resistance among all samples. The results obtained in this study suggest that the LDH content in the film could be related to the corrosion resistance of the film.

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AuNPs-Based Thermoresponsive Nanoreactor as an Efficient Catalyst for the Reduction of 4-Nitrophenol

Nanomaterials ◽

10.3390/nano8120963 ◽

2018 ◽

Vol 8 (12) ◽

pp. 963

Author(s):

Wei Liu ◽

Xiaolian Zhu ◽

Chengcheng Xu ◽

Zhao Dai ◽

Zhaohui Meng

Keyword(s):

Aqueous Solution ◽

Electron Transfer ◽

Phase Transformation ◽

Catalytic Activity ◽

Catalytic Efficiency ◽

Environmental Pollutant ◽

Temperature Sensitive ◽

Efficient Catalyst ◽

Catalytic Rate ◽

Silica Core

A new AuNPs-based thermosensitive nanoreactor (SiO2@PMBA@Au@PNIPAM) was designed and prepared by stabilizing AuNPs in the layer of poly(N,N’-methylenebisacrylamide) (PMBA) and subsequent wrapping with the temperature-sensitive poly(N-isopropylacrylamide) (PNIPAM) layer. The new nanoreactor exhibited high dispersibility and stability in aqueous solution and effectively prevented the aggregation of AuNPs caused by the phase transformation of PNIPAM. The XPS and ATR-FTIR results indicated that AuNPs could be well stabilized by PMBA due to the electron transfer between the N atoms of amide groups in the PMBA and Au atoms of AuNPs. The catalytic activity and thermoresponsive property of the new nanoreactor were invested by the reduction of the environmental pollutant, 4-nitrophenol (4-NP), with NaBH4 as a reductant. It exhibited a higher catalytic activity at 20 °C and 30 °C (below LCST of PNIPAM), but an inhibited catalytic activity at 40 °C (above LCST of PNIPAM). The PNIPAM layer played a switching role in controlling the catalytic rate by altering the reaction temperature. In addition, this nanoreactor showed an easily recyclable property due to the existence of a silica core and also preserved a rather high catalytic efficiency after 16 times of recycling.

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