scholarly journals Heat Treatment Effect in the Corrosion Resistance of the Al-Co-Mn Alloys Immersed in 3 M KOH

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
J. G. Pereyra-Hernández ◽  
I. Rosales-Cadena ◽  
R. Guardián-Tapia ◽  
J. G. González-Rodríguez ◽  
R. López-Sesenes

Al-based alloys named M1, M2, M3, M4, and M5 doped with different atomic percentage (at%) of cobalt and manganese as cast and submitted at two heat treatments (600°C and 1100°C) were analyzed by using electrochemical techniques to evaluate their corrosion resistance immersed in 3 M KOH. With the heat treatments applied to the alloys, the sample M2 (65% Al, 20% Co, and 15% Mn) observed the highest corrosion resistance with R p values of 3.0 × 10 2 , 6.2 × 10 2 , and 1.61 × 10 3   Ω · c m 2 as cast, 600°C, and 1100°C, respectively. The latter was in agreement with the I corr calculated from the polarization curves where the values decrease based on the heat treatment applied as follows: 1.60 × 10 3 > 6.16 × 10 2 > 3.07 × 10 2   mA / c m 2 for 1100, 600, and as cast, respectively. Co concentration above 20% increases the corrosion current ( I corr ) and decreases the polarization resistance of the remain samples. The chemical analysis done with EDS and X-ray diffraction made confirmed the presence of compounds such as CoAl, Co2Al5, Co2Al9, MnAl4, and MnAl6.

2018 ◽  
Vol 25 (08) ◽  
pp. 1950023 ◽  
Author(s):  
ARKADEB MUKHOPADHYAY ◽  
TAPAN KUMAR BARMAN ◽  
PRASANTA SAHOO

The present work reports the deposition of a quaternary Ni-B-W-Mo coating on AISI 1040 medium carbon steel and its characterization. Quaternary deposits are obtained by suitably modifying existing electroless Ni-B bath. Composition of the as-deposited coating is analyzed by energy dispersive X-ray spectroscopy. The structural aspects of the as-deposited and coatings heat treated at 300[Formula: see text]C, 350[Formula: see text]C, 400[Formula: see text]C, 450[Formula: see text]C and 500[Formula: see text]C are determined using X-ray diffraction technique. Surface of the as-deposited and heat-treated coatings is examined using a scanning electron microscope. Very high W deposition could be observed when sodium molybdate is present in the borohydride-based bath along with sodium tungstate. The coatings in their as-deposited condition are amorphous while crystallization takes place on heat treatment. A nodulated surface morphology of the deposits is also observed. Vickers’ microhardness and crystallite size measurement reveal inclusion of W and Mo results in enhanced thermal stability of the coatings. Solid solution strengthening of the electroless coatings by W and Mo is also observed. The applicability of kinetic strength theory to the hardening of the coatings on heat treatment is also investigated. Corrosion resistance of Ni-B-W-Mo coatings and effect of heat treatment on the same are also determined by electrochemical techniques.


DYNA ◽  
2018 ◽  
Vol 85 (207) ◽  
pp. 192-197 ◽  
Author(s):  
Estrella Natali Borja-Goyeneche ◽  
Jhon Jairo Olaya-Florez

This work researches the influence of the nickel content on the structural and anticorrosive properties of ZrSiTiN films deposited by means of reactive co-sputtering on alloys of Ti6Al4V. The morphology and structure were analyzed by means of scanning electron microscopy (SEM) and X-ray diffraction (XRD), and the chemical composition was identified via X-ray scattering spectroscopy (EDS). The corrosion resistance was studied using potentiodynamic polarization (PP) tests employing a 3.5% by weight NaCl solution. In the films, an increase of Ni up to 6.97 at% was observed, while in XRD the FCC phase of (Zr, Ti) N was identified, with a mixed orientation in planes (111) and (200), which tended to diminish with the increase of Ni. Finally, with the addition of Ni, the corrosion current densities were reduced from 5.56 𝑥 10−8 to 2.64 𝑥 10−9 𝐴/𝑐m2. The improvement in the corrosion resistance is due to the effect of the Ni on the microstructure of the system (Zr, Ti) N, which can improve the quality of the passive film and prevent crystalline defects and corrosion zones.


2012 ◽  
Vol 184-185 ◽  
pp. 1175-1180
Author(s):  
Guo Liang Li ◽  
Xiao Hua Jie ◽  
Bi Xue Yang

Amorphous Cr–C alloy coating was prepared by electrodepositing. The microhardness of the coating was tested after annealing from 100°C to 800°C and the crystallization evolution was studied by the analysis of X-ray diffraction (XRD) and differential scanning caborimetry (DSC). The results showed that the crystallization evolution of the coating began at 300°C and finished around 450°C, and intermetallic compound Cr7C3and Cr23C6appeared when heat treatment temperature reached around 600°C. The microhardness, corrosion resistance as well as the adhesion of the coating all increased first with the temperature and then dropped until it attained the proper values. The microhardness reached the maximum of 1610HV0.025at 600°C. While the corrosion resistance and the adhesion force attained the peak value at about 400°C.


2012 ◽  
Vol 581-582 ◽  
pp. 773-776
Author(s):  
Er Chao Ding ◽  
Zhen Yong Man ◽  
Xin Xin Yang ◽  
Jing Tai Zhao

The effects of heat treatment on microstructure and corrosion resistance of Ni-Cr-Mo-Fe nickel-based alloys were investigated by X-ray diffraction (XRD), metallographic microscope (MM), scanning electron microscopy (SEM) and electrochemical analysis, respectively. Experimental results indicated that the samples which were prepared via electric arc melting shielded by argon were pure solid solutions with homogeneous microstructure. Segregation of chromium element and slightly smaller grain size were found after heat treatment. Better corrosion resistance of samples was achieved after heat treatment, due to improvement of microstructure, morphology and distribution of elements.


Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7389
Author(s):  
Michael Kahl ◽  
Teresa D. Golden

Modified zaccagnaite layered double hydroxide (LDH) type films were synthesized on steel substrates by pulsed electrochemical deposition from aqueous solutions. The resulting films were characterized by X-ray diffraction, scanning electron microscopy/X-ray dispersive spectroscopy, and Fourier transform infrared spectroscopy. Structural characterization indicated a pure layered double hydroxide phase; however, elemental analysis revealed that the surface of the films contained Zn:Al ratios outside the typical ranges of layered double hydroxides. Layer thickness for the deposited films ranged from approximately 0.4 to 3.0 μm. The corrosion resistance of the film was determined using potentiodynamic polarization experiments in 3.5 wt.% NaCl solution. The corrosion current density for the coatings was reduced by 82% and the corrosion potential was shifted 126 mV more positive when 5 layers of modified LDH coatings were deposited onto the steel substrates. A mechanism was proposed for the corroding reactions at the coating.


Coatings ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 858
Author(s):  
Shenglin Liu ◽  
Yongsheng Zhu ◽  
Xinyue Lai ◽  
Xueping Zheng ◽  
Runnan Jia ◽  
...  

Fe-based amorphous/nanocrystalline coatings with smooth, compact interior structure and low porosity were fabricated via supersonic plasma spraying (SPS). The coatings showed outstanding corrosion resistance in a 3.5% NaCl solution at room temperature. In order to analyze the effect of annealing treatment on the microstructure, corrosion resistance and microhardness, the as-sprayed coating was annealed for 1 h under different temperatures such as 350, 450, 550 and 650 °C, respectively. The results showed that the number of oxides and cracks in the coatings presented an obvious increase with increasing annealing temperature, and the corrosion resistance of the coatings showed an obvious reduction. However, the microhardness of coatings showed an important increase. The microhardness of the coating could reach 1018 HV when the heat treatment temperature reached 650 °C. The X-ray diffraction (XRD) results showed that there appeared a number of crystalline phases in the coating when the heat treatment temperature was at 650 °C. The crystalline phases led to the increase of the microhardness.


1974 ◽  
Vol 54 (4) ◽  
pp. 395-401 ◽  
Author(s):  
C. R. DE KIMPE

The clay fraction from various horizons of two Podzols sampled in the Appalachian Highlands was analyzed by X-ray diffraction and by a quantitative mineralogical procedure. Different cation saturation and heat treatments made it possible to detect differences in the mineralogical properties of the clays of the Ae horizon, but did not cause appreciable differences in the spectra of B and C horizon samples. In the Ae horizon, the clays were shown to have properties of both vermiculites and smectites. The paragonite-like structure induced by Na-saturation and moderate heat treatment is characteristic of minerals in the early stages of weathering from dioctahedral illites.


Coatings ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 616
Author(s):  
Zhaoyang Song ◽  
Hongwen Zhang ◽  
Xiuqing Fu ◽  
Jinran Lin ◽  
Moqi Shen ◽  
...  

The objective of this study was to improve the surface properties, hardness, wear resistance and electrochemical corrosion resistance of #45 steel. To this end, Ni–P–ZrO2–CeO2 composite coatings were prepared on the surface of #45 steel using the jet-electrodeposition technique by varying the current density from 20 to 60 A/dm2. The effect of current density on the performance of the composite coatings was evaluated. Scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD) were applied to explore the surface topography, elemental composition, hardness and electrochemical corrosion resistance of the composite coatings. The results showed that with the increase in the current density, the hardness, wear resistance, and electrochemical corrosion resistance tends to increase first and then decrease. At a current density of 40 A/dm2, the hardness reached a maximum of 688.9 HV0.1, the corrosion current reached a minimum of 8.2501 × 10−5 A·cm−2, and the corrosion potential reached a maximum of −0.45957 V. At these values, the performance of the composite coatings was optimal.


2013 ◽  
Vol 456 ◽  
pp. 438-441 ◽  
Author(s):  
Tian Yang ◽  
Cheng Zhang Peng ◽  
Lang Xiang ◽  
Huo Cao

The electroplated Ni-Co-Cr coatings were prepared on surface of a low carbon steel. The microstructure of the deposits were analyzed by scanning electron microscope (SEM) and X-ray diffraction (XRD), the corrosion resistance of the deposits was evaluated using neutral salt-spray test and polarization measurement. The results show that the deposits are a Co and Cr solid solution in Ni with a grain size of 6.9~10.6nm, were nearly free of corrosion after neutral salt-spray tested 100 hours. With chromium content increasing, the coatings exhibited higher corrosion potential and lower corrosion current, which revealed excellent corrosion resistance.


2017 ◽  
Vol 62 (4) ◽  
pp. 2101-2106
Author(s):  
M. Kciuk ◽  
S. Lasok

AbstractThe paper presents the influence of heat treatment on the structure and corrosion resistance of X5CrNi18-10 steel. To determine the structure which has been obtained after heat treatment the methods of light and scanning electron microscopy with EDS microanalysis were used. The electrochemical corrosion properties of the investigated steel were studied in 3.5% NaCl solution using potentiodynamic polarization tests. Basing on the registered curves, the corrosion current, polarization resistance and corrosion potential were determined. The corrosion tests were followed by fractographic researches.


Sign in / Sign up

Export Citation Format

Share Document