EFFECT OF DISCHARGE TIME ON PLASMA ELECTROLYTIC BOROCARBONITRIDING OF PURE IRON

2017 ◽  
Vol 24 (02) ◽  
pp. 1750016 ◽  
Author(s):  
XIAOYUE JIN ◽  
JIE WU ◽  
BIN WANG ◽  
XUAN YANG ◽  
LIN CHEN ◽  
...  
Keyword(s):  
Pure Iron ◽  
Electrochemical Impedance ◽  
Wear Behavior ◽  
Boride Layer ◽  
Dry Sliding ◽  
Discharge Time ◽  
Borax Solution ◽  
N Treatment ◽  
Sliding Test ◽  
Plasma Electrolytic

The plasma electrolytic borocarbonitriding (PEB/C/N) process on pure iron was carried out in 25% borax solution with glycerine and carbamide additives under different discharge time at 360[Formula: see text]V. The morphology and structure of PEB/C/N hardened layers were analyzed by SEM and XRD. The hardness profiles of hardened layers were measured by microhardness test. Corrosion behavior of PEB/C/N layers was evaluated by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). Their wear performance was carried out using a pin-disc friction and wear tester under dry sliding test. The PEB/C/N samples mainly consisted of [Formula: see text]-Fe, Fe2B, Fe3C, FeN, FeB, Fe2O3 and Fe4N phases, and the Fe2B phase was the dominant phase in the boride layer. It was found that the thickness of boride layer increased with the discharge time and reached 14[Formula: see text][Formula: see text]m after 60[Formula: see text]min treatment. The microhardness of the boride layer was up to 2100[Formula: see text]HV, which was much higher than that of the bare pure iron (about 150[Formula: see text]HV). After PEB/C/N treatment, the corrosion resistance of pure iron was slightly improved. The friction coefficient of PEB/C/N treated pure iron decreased to 0.129 from 0.556 of pure iron substrate. The wear rate of the PEB/C/N layer after 60[Formula: see text]min under dry sliding against ZrO2 ball was only 1/10 of that of the bare pure iron. The PEB/C/N treatment is an effective way to improve the wear behavior of pure iron.

scholarly journals Advanced Corrosion Protection of Additive Manufactured Light Metals by Creating Ceramic SurfaceThrough CERANOD® Plasma Electrolytical Oxidation Process

2021 ◽  
Vol 3 ◽  
Author(s):  
Patcharawee Jantimapornkij ◽  
Jörg Zerrer ◽  
Anna Buling
Keyword(s):  
Corrosion Protection ◽  
Electrochemical Impedance ◽  
Wear Behavior ◽  
Light Metal ◽  
Localized Corrosion ◽  
Full Potential ◽  
Oxide Ceramic ◽  
Light Metals ◽  
Metal Printing ◽  
Plasma Electrolytic

Lightweight structures produced by additive manufacturing (AM) technology such as the selective laser melting (SLM) process enable the fabrication of 3D structures with a high degree of freedom. A printed component can be tailored to have specific properties and render possible applications for industries such as the aerospace and automotive industries. Here, AlSi10Mg is one of the alloys that is currently used for SLM processes. Although the research with the aim improving the strength of AM aluminum alloy components is rapidly progressing, corrosion protection is scarcely addressed in this field. Plasma electrolytic oxidation (PEO) is an advanced electrolytical process for surface treatment of light metals such as aluminum, magnesium, and titanium. This process produces an oxide ceramic-like layer, which is extremely hard but also ductile, and significantly improves the corrosion and wear behavior. The aim of this study is to understand the corrosion behavior of 3D-printed AlSi10Mg alloy and to improve its corrosion resistance. For this reason, the properties of CERANOD®—PEO coating on an AlSi10Mg alloy produced by SLM were investigated on different AM surfaces, i.e., as-built, polished and stress relieved specimens. The corrosion performance of these surfaces was analyzed using electrochemical impedance spectroscopy (EIS), potentiodynamic polarization, and long-term immersion tests. Moreover, the microstructure and morphology of the resulting coatings were characterized by SEM/EDS, taking into account the corrosive attacks. The results exhibited a high amount of localized corrosion in the case of the uncoated specimens, while the PEO process conducted on the aluminum AM surfaces led to enclosed homogeneous coatings by protecting the material’s pores, which are typically observed in AM process. Thereby, high corrosion protection could be achieved using PEO surfaces, suggesting that this technology is a promising candidate for unleashing the full potential of 3D light metal printing.

FABRICATION AND WEAR BEHAVIOR OF PEC/N HARDENED LAYER ON PURE IRON

2021 ◽  
Author(s):  
XIAOYUE JIN ◽  
LIN CHEN ◽  
KEJIAN WEI ◽  
RUIHONG LIU ◽  
JIAHAO YU ◽  
...  
Keyword(s):  
Pure Iron ◽  
Diffusion Rate ◽  
Wear Behavior ◽  
Hardened Layer ◽  
Layer Growth ◽  
Plasma Electrolytic Treatment ◽  
C And N ◽  
Cathodic Plasma ◽  
Plasma Electrolytic ◽  
And Diffusion

In this paper, the antifriction carbonitriding (PEC/N) layers were prepared on pure iron by cathodic plasma electrolytic treatment (PET) in glycerin and carbamide aqueous solution under 360[Formula: see text]V for 1, 3 and 10[Formula: see text]min. Influence of discharge time on morphology, structure, surface roughness and microhardness of PEC/N layer was analyzed. The tribological performance of the PEC/N layer, growth mechanism and diffusion process during PEC/N treatment was investigated. The thickness of the PEC/N layer grew to 48[Formula: see text][Formula: see text]m for 10[Formula: see text]min treatment and the growth of the saturation layer met the parabolic law. The highest microhardness of the surface was up to 811 HV, which was 5 times of that of iron substrate. The PEC/N layer consisted of [Formula: see text]-Fe, Fe[Formula: see text]N, Fe4N, Fe3C, Fe5C2 phases and a little FeO phase. The wear rate of the PEC/N layer reduced by five-sixes comparing with the iron substrate and the surface of the wear track was much smoother. The temperature close to the surface during PEC/N fitted by the tested temperature values inside the sample was 801∘C (1074[Formula: see text]K), and the combination diffusion rate of C and N into pure iron during PET at 360[Formula: see text]V reached [Formula: see text][Formula: see text]m2/s. The electron temperature fluctuates between 3000[Formula: see text]K and 8000[Formula: see text]K. The antifriction PEC/N layer displayed a very good wear resistance and the higher diffusion rate makes plasma electrolytic carbonitriding a very effective technique for surface modification of pure iron.

FABRICATION AND CHARACTERIZATION OF PLASMA ELECTROLYTIC BOROCARBURIZED LAYERS ON Q235 LOW-CARBON STEEL AT DIFFERENT DISCHARGE VOLTAGES

2016 ◽  
Vol 24 (06) ◽  
pp. 1750088 ◽  
Author(s):  
BIN WANG ◽  
JIE WU ◽  
XIAOYUE JIN ◽  
XIAOLING WU ◽  
ZHENGLONG Wu ◽  
...  
Keyword(s):  
Carbon Steel ◽  
Applied Voltage ◽  
Low Carbon Steel ◽  
Boride Layer ◽  
Layer Growth ◽  
Low Carbon ◽  
High Concentration ◽  
Xps Spectra ◽  
Borax Solution ◽  
Plasma Electrolytic

The influence of applied voltage on the plasma electrolytic borocarburizing (PEB/C) layer of Q235 low-carbon steel in high-concentration borax solution was investigated. XRD and XPS spectra of PEB/C layer confirmed that the modified boride layer mainly consisted of Fe2B phase, and the FeB phase only exists in the loose top layer. The applied voltage on Q235 steel played a key role in determining the properties of hardened layers. The thickness and microhardness of boride layers increased with the increase of the applied voltage, which led to superior corrosion and wear resistances of Q235 low-carbon steel. The diffusion coefficient ([Formula: see text] of boride layer at 280, 300 and 330[Formula: see text]V increased with borocarburizing temperature and ranged from [Formula: see text][Formula: see text]m2/s to [Formula: see text][Formula: see text]m2/s. The activation energy ([Formula: see text] of boride layer growth during PEB/C treatment was only 52.83[Formula: see text][Formula: see text], which was much lower than that of the conventional boriding process.

Dry sliding wear behavior of aluminum graphene nanoplatelet (GNP) composites

2016 ◽  
Vol 58 (7-8) ◽  
pp. 640-643 ◽  
Author(s):  
Ilyas Istif ◽  
Mehmet Tunc Tuncel
Keyword(s):  
Sliding Wear ◽  
Wear Behavior ◽  
Dry Sliding Wear ◽  
Dry Sliding ◽  
Graphene Nanoplatelet

scholarly journals Investigation of Growth Mechanism of Plasma Electrolytic Oxidation Coating on Al-Ti Double-Layer Composite Plate

Materials ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 272 ◽  
Author(s):  
Quanzhi Chen ◽  
Weizhou Li ◽  
Kui Ling ◽  
Ruixia Yang
Keyword(s):  
Double Layer ◽  
Growth Mechanism ◽  
Plasma Electrolytic Oxidation ◽  
Composite Plate ◽  
Electrochemical Impedance ◽  
Electric Energy ◽  
Layer Composite ◽  
Electrolytic Oxidation ◽  
Plasma Electrolytic ◽  
Coating Growth

The aluminum–titanium (Al-Ti) double-layer composite plate is a promising composite material, but necessary surface protection was required before its application. In this paper, plasma electrolytic oxidation (PEO) was employed to fabricate a ceramic coating on the surface of a Al-Ti double-layer composite plate. To investigate the coating growth mechanism on the Al-Ti double-layer composite plate, a single-Al plate and a single-Ti plate were introduced for comparison experiments. Results showed that, the composite of Al and Ti accelerated the coating growth rate on the part-Ti portion of the composite plate, and that of the part-Al portion was decreased. Electrochemical impedance spectroscopy analysis indicated that the equivalent circuit of the Al-Ti coating was formed by connecting two different circuits in parallel. The reaction behavior revealed that the electric energy during the PEO would leak from the circuit with the weaker blocking effect, and confirmed that the electric energy distribution followed the law of low-resistance distribution. Finally, the mechanism was extended to the PEO treatment on general metal matrix composites to broaden the application theory of the technology.

scholarly journals Design and Multidimensional Screening of Flash-PEO Coatings for Mg in Comparison to Commercial Chromium(VI) Conversion Coating

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 337
Author(s):  
Ewa Wierzbicka ◽  
Marta Mohedano ◽  
Endzhe Matykina ◽  
Raul Arrabal
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Protection ◽  
Electrochemical Impedance ◽  
Salt Spray ◽  
Conversion Coating ◽  
Neutral Salt ◽  
Chromium Vi ◽  
Alkaline Electrolytes ◽  
Az31b Alloy ◽  
Plasma Electrolytic

REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals) regulations demand for an expedient discovery of a Cr(VI)-free alternative corrosion protection for light alloys even though the green alternatives might never be as cheap as current harmful technologies. In the present work, flash- plasma electrolytic oxidation coatings (FPEO) with the process duration < 90 s are developed on AZ31B alloy in varied mixtures of silicate-, phosphate-, aluminate-, and fluoride-based alkaline electrolytes implementing current density and voltage limits. The overall evaluation of the coatings’ anticorrosion performance (electrochemical impedance spectroscopy (EIS), neutral salt spray test (NSST), paintability) shows that from nine optimized FPEO recipes, two (based on phosphate, fluoride, and aluminate or silicate mixtures) are found to be an adequate substitute for commercially used Cr(VI)-based conversion coating (CCC). The FPEO coatings with the best corrosion resistance consume a very low amount of energy (~1 kW h m−2 µm−1). It is also found that the lower the energy consumption of the FPEO process, the better the corrosion resistance of the resultant coating. The superb corrosion protection and a solid environmentally friendly outlook of PEO-based corrosion protection technology may facilitate the economic justification for industrial end-users of the current-consuming process as a replacement of the electroless CCC process.

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