Electrochemical Behaviours of Titanium Nitride (TiN) and Chromium Nitride (CrN) Based PVD Coating Systems

2013 ◽  
Author(s):  
Feng Cai ◽  
Xiao Huang ◽  
Qi Yang
Keyword(s):  
Diffusion Layer ◽  
Electrochemical Impedance ◽  
Effective Diffusion ◽  
Electrochemical Corrosion ◽  
Hard Coatings ◽  
Corrosive Media ◽  
Diffusion Layer Thickness ◽  
Growth Defects ◽  
Coating Failure ◽  
Coating Microstructure

Hard coatings applied to steel components prevent corrosion attacks while at the same time mitigate erosion attack. However, the presence of process related through-coating defects such as pin holes, voids and growth defects, provides accesses for corrosive media to metal substrates, initializing pitting corrosion and eventually resulting in coating failure. This research studies the corrosion behavior of PVD TiN and CrN (CrSiCN) coated steels in 3.5 wt. % NaCl aqueous solution using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. The results revealed that in a coating-substrate system, effective diffusion coefficient and diffusion layer thickness control the corrosion resistance; both factors are found to be related to coating microstructure. A denser and thicker coating structure are shown to have lower effective diffusion coefficients and greater effective diffusion layer thicknesses and consequently provided a high resistance to electrochemical corrosion.

scholarly journals Influence of Growth Defects on the Corrosion Resistance of Sputter-Deposited TiAlN Hard Coatings

Coatings ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 511 ◽  
Author(s):  
Panjan ◽  
Drnovšek ◽  
Gselman ◽  
Čekada ◽  
Panjan ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Cross Sections ◽  
Focused Ion Beam ◽  
Electrochemical Impedance ◽  
Ion Beam ◽  
Hard Coatings ◽  
Growth Defects ◽  
Coating Morphology ◽  
Before And After ◽  
Sputter Deposited

In this work, the causes of porosity of TiAlN hard coatings sputter deposited on D2 tool steel were studied since its corrosion resistance is mainly affected by imperfections within the coating (e.g., pinholes, pores, crevices). The corrosion test was performed in a chlorine solution using electrochemical impedance spectroscopy. The coating morphology of growth defects before and after the exposure was studied by scanning electron microscopy (SEM), while focused ion beam (FIB) was used to make series of cross-sections through individual selected defects. We confirm that pitting corrosion is closely related to the through-thickness growth defects. It was also found that in the case of nodular defects, the intensity of corrosion depends on the shape of the seed.

A review on the corrosion resistance of electroless Ni-P based composite coatings and electrochemical corrosion testing methods

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Imtiaz Ahmed Shozib ◽  
Azlan Ahmad ◽  
Ahmad Majdi Abdul-Rani ◽  
Mohammadali Beheshti ◽  
Abdul’Azeez Abdu Aliyu
Keyword(s):  
Corrosion Resistance ◽  
Electrochemical Impedance ◽  
Composite Coatings ◽  
Electrochemical Corrosion ◽  
Kelvin Probe ◽  
Corrosive Media ◽  
Measuring Techniques ◽  
Electroless Ni ◽  
The Impact ◽  
Electrode Technique

Abstract This paper aims to review the impact of different factors influencing the corrosion resistance of electroless Ni-P based coatings. Emphasis has been given onto the impact of phosphorus content, incorporation of alloying elements, addition of particles and heat treatment which have been discussed in detail and critically reviewed. The effect of corrosive media and coating process parameters on corrosion resistance are studied concisely. Furthermore, the role of the incorporation of various elements and particles’ contents on the corrosion resistance of electroless Ni-P coating are studied systematically. This paper also presents an overview of the latest electrochemical corrosion measuring techniques. The following approaches deserve special attention in the analysis: localized electrochemical impedance spectroscopy (LEIS), scanning vibrating electrode technique (SVET), scanning ion-selective electrode technique (SIET), scanning droplet cell (SDC), scanning electrochemical microscopy (SECM), scanning Kelvin probe (SKP) and novel contactless technique (NCT).

Interaction between Sodium Molybdate and FSWed Wled of 5083 Effected by Time

2013 ◽  
Vol 699 ◽  
pp. 645-649
Author(s):  
Chang Bin Shen
Keyword(s):  
Inhibition Efficiency ◽  
Electrochemical Impedance ◽  
Electrochemical Corrosion ◽  
Sodium Molybdate ◽  
Impedance Spectra ◽  
Electrochemical Impedance Spectra ◽  
Friction Stir ◽  
Base Materials ◽  
Corrosion Behaviors ◽  
5083 Aluminum Alloy

Similar welds composed of 5083 were produced by friction stir welding. In the solution of 0.2 M NaHSO3 and 0.6 M NaCl, with the addition of a given concentration sodium molybdate as the inhibitor, the electrochemical corrosion behaviors of the friction stir welds (FSW) and 5083 were comparatively investigated by potentiodynamic polarization curve tests and electrochemical impedance spectra (EIS) at the ambient temperature for different test periods. The results indicated that : with the extension of period, the inhibition efficiencies (IE) for both the weld and 5083 base materials enhanced, at the same period, the inhibition efficiency (IE) for the weld was beyond that for 5083 base materials, sodium molybdate may be thought of as an effective inhibitor for 5083 aluminum alloy, the interaction between inhibitor and weld is stronger than that between inhibitor and base materials.

The Detection And Mapping Of Defects In Organic Coatings Using Local Electrochemical Impedance Methods

1995 ◽  
Vol 411 ◽  
Author(s):  
S. R. Taylor ◽  
M. W. Wittmann
Keyword(s):  
Electrochemical Impedance ◽  
Organic Coatings ◽  
Single Frequency ◽  
Probe Design ◽  
Coating Failure ◽  
Local Electrochemical Impedance Spectroscopy ◽  
Physical Defects ◽  
Steel Substrates ◽  
Insight Into

ABSTRACTCoating failure initiates as a local event at defects which can result from chemical heterogeneities in the resin or physical defects such as bubbles, underfilm deposits, or pinholes. The ability to detect, map the location, as well as make quantitative in-situ measurements of coating heterogeneities will help identify the source of failure (i.e. coating chemistry, method of application, cure schedule, etc.) and provide insight into the mechanisms of coating degradation. This study used a 5 electrode arrangement to perform local electrochemical impedance spectroscopy (LEIS) on coated steel substrates. Using single frequency measurements, LEIS could successfully detect and map both intentional chemical heterogeneities and physical defects such as subsurface bubbles, underfilm deposits, and pinholes. Efforts to optimize probe design and instrumentation are ongoing.

Effect of Nanoparticle Addition in Hybrid Sol-Gel Silane Coating on Corrosion Resistance of Low Carbon Steel

2013 ◽  
Vol 686 ◽  
pp. 244-249 ◽  
Author(s):  
Poovarasi Balan ◽  
Aaron Ng ◽  
Chee Beng Siang ◽  
R.K. Singh Raman ◽  
Eng Seng Chan
Keyword(s):  
Corrosion Resistance ◽  
Carbon Steel ◽  
Electrochemical Impedance ◽  
Sol Gel ◽  
Low Carbon Steel ◽  
Electrochemical Corrosion ◽  
Alumina Nanoparticles ◽  
Low Carbon ◽  
Silane Coating ◽  
Sol Gel Films

Chromium pre-treatments of metal have been replaced by silane pre-treatments as more environmental friendly option. Nanoparticles can be added in the silane sol-gel network have been reported to improve corrosion resistance. In this work, the electrochemical corrosion resistance of low carbon steel coated with hybrid organic-inorganic sol-gel film filled with nanoparticles was evaluated. The sol-gel films have been synthesized from 3-glycidoxy-propyl-trimethoxy-silane (3-GPTMS) and tetra-ethyl-ortho-silicate (TEOS) precursors. These films have been impregnated with 300 ppm of silica or alumina nanoparticles. The electrochemical behavior of the coated steel was evaluated by means of electrochemical impedance spectroscopy (EIS) and scanning electron microscopy (SEM). Equivalent circuit modeling, used for quantifying the EIS measurements showed that sol-gel films containing silica nanoparticles improved the barrier properties of the silane coating. The silica nanoparticle-containing films showed highest initial pore resistance over the five days of immersion in 0.05M NaCl.

Corrosion Protection of Nano-Silica Powder Coatingon Artificial Seawater

2021 ◽  
Vol 904 ◽  
pp. 519-524
Author(s):  
Gui Yun Zhang ◽  
Yong Wang ◽  
Tian Wei Zhang ◽  
Chen Yu Zhao
Keyword(s):  
Corrosion Protection ◽  
Corrosion Behavior ◽  
Sea Water ◽  
Electrochemical Impedance ◽  
Water Solution ◽  
Electrochemical Corrosion ◽  
Artificial Seawater ◽  
Protection Effect ◽  
Aluminum Sheets ◽  
Electrochemical Corrosion Behavior

Sea water resources are extensive and can be used to extinguish fires, but their corrosiveness is a major problem. Using the method of electrochemical workstation, the electrochemical corrosion behavior of aluminum sheet in artificial sea water solution and silica-coated artificial seawater was studied; by analyzing the surface morphology, polarization curve and electrochemical impedance spectroscopy, the electrochemical corrosion behavior of aluminum sheets under different immersion times and different immersion media is obtained. The conclusion is that the coating of nanosilica powder has a certain corrosion protection effect on artificial seawater.

Growth Defects in PVD Hard Coatings

2020 ◽  
pp. 35-73
Author(s):  
Miha Čekada ◽  
Peter Panjan ◽  
Aljaž Drnovšek ◽  
Matjaž Panjan ◽  
Peter Gselman
Keyword(s):  
Hard Coatings ◽  
Growth Defects

scholarly journals Tribological and Electrochemical Characterization of UHMWPE Hybrid Nanocomposite Coating for Biomedical Applications

Materials ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 3665
Author(s):  
Zahid Ahmed Baduruthamal ◽  
Abdul Samad Mohammed ◽  
A. Madhan Kumar ◽  
Mohamed A. Hussein ◽  
Naser Al-Aqeeli
Keyword(s):  
Electrochemical Impedance ◽  
Electrochemical Corrosion ◽  
Spray Coating ◽  
High Hardness ◽  
Weight Percent ◽  
Scratch Resistance ◽  
Nanocomposite Coating ◽  
Hybrid Nanocomposite ◽  
Electrochemical Corrosion Behavior ◽  
Wear And Corrosion Resistance

A new approach of using a polymer hybrid nanocomposite coating to modify the surface of titanium and its alloys is explored in this study. Electrostatic spray coating process is used to deposit the coating on the plasma-treated substrates for better adhesion. Ultra-high molecular weight polyethylene (UHMWPE) has been selected as the parent matrix for the coating due to its biocompatibility and excellent tribological properties. However, to improve its load-bearing capacity carbon nanotubes (CNT’s) (0.5, 1.5, and 3 wt.%) are used as reinforcement and to further enhance its performance, different weight percent of hydroxyapatite (HA) (0.5, 1.5, 3, and 5 wt.%) are introduced to form a hybrid nanocomposite coating. The dispersion of CNT’s and HA was evaluated by Raman spectroscopy and scanning electron microscopy. The electrochemical corrosion behavior of the nanocomposite coatings was evaluated by performing potentiodynamic polarization and electrochemical impedance spectroscopic tests in simulated body fluid. Tribological performance of the developed hybrid nanocomposite coating was evaluated using a 6.3 mm diameter stainless steel (440C) ball as the counterface in a ball-on-disk configuration. Tests were carried out at different normal loads (7 N, 9 N, 12 N, and 15 N) and a constant sliding velocity of 0.1 m/s. The developed hybrid nanocomposite coating showed excellent mechanical properties in terms of high hardness, improved scratch resistance, and excellent wear and corrosion resistance compared to the pristine UHMWPE coatings.

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