scholarly journals HEAT TREATMENT EFFECT OF HEXAGONAL BORON NITRIDE REINFORCED ELECTROLESS NICKEL COATINGS

2019 ◽  
Author(s):  
Mustafa Kocabaş ◽  
Halil Yılmaz ◽  
Nurhan Cansever
Keyword(s):  
Heat Treatment ◽  
Boron Nitride ◽  
Treatment Effect ◽  
Hexagonal Boron Nitride ◽  
Electroless Nickel ◽  
Nickel Coatings

Corrosion and Wear Behavior of Electroless Nickel Coatings

2020 ◽  
pp. 210-227
Author(s):  
Suman Kalyan Das ◽  
Supriyo Roy ◽  
Prasanta Sahoo
Keyword(s):  
Heat Treatment ◽  
Wear Behavior ◽  
Current Source ◽  
High Hardness ◽  
Electroless Nickel ◽  
Treatment Temperature ◽  
Corrosion And Wear ◽  
Uniform Coating ◽  
Nickel Coatings ◽  
Electroless Coatings

This chapter describes how corrosion is the degradation of a material due to a reaction with its environment. Wear is another deteriorating phenomenon which erodes the contacting surfaces of any mechanical component gradually. Although corrosion and wear are two different phenomenon they are often interdependent and in most practical situations take place simultaneously. Fortunately, several surface modification methods exist which can protect the surface of metal against corrosion and wear. Among them, electroless nickel coatings is a technology where a coating is applied without the use of external current source. The primary advantages of electroless coatings include uniform coating and ability to coat non-conductive materials. Electroless nickel coatings possess excellent properties such as high hardness, good wear resistance and corrosion resistance. The corrosion and wear behavior of these coatings mainly depend on bath ingredients, deposition conditions, heat treatment temperature, etc.

Intercalation of hexagonal boron nitride and graphite with lithium by sequential process of ball milling and heat treatment

2017 ◽  
Vol 707 ◽  
pp. 172-177 ◽  
Author(s):  
Jungryang Kim ◽  
Eiji Yamasue ◽  
Hideyuki Okumura ◽  
Chishiro Michioka ◽  
Keiichi N. Ishihara
Keyword(s):  
Heat Treatment ◽  
Boron Nitride ◽  
Ball Milling ◽  
Hexagonal Boron Nitride ◽  
Sequential Process

Comparison of Various Electroless Nickel Coatings on Steel: Structure, Hardness and Abrasion Resistance

2014 ◽  
Vol 783-786 ◽  
pp. 1405-1413 ◽  
Author(s):  
Véronique Vitry ◽  
Adeline Sens ◽  
Fabienne Delaunois
Keyword(s):  
Heat Treatment ◽  
Wear Resistance ◽  
Steel Substrate ◽  
Steel Structure ◽  
Electroless Nickel ◽  
Scratch Testing ◽  
Nickel Coatings ◽  
Heat Treated ◽  
Nickel Deposits ◽  
Heat Treated Condition

Several electroless nickel deposits, on steel substrate, of varying chemistry were investigated in the as-plated and heat-treated condition: 3 nickel-phosphorous (low, mid and high P) and 2 nickel-boron (nickel-boron (lead) and nickel-boron (thallium)). Samples were characterized by SEM and X-ray diffraction. They were then submitted to Knoops microhardness testing and Taber abrasion tests, with abrasive CS-10 wheels, as well as scratch testing to investigate their mechanical properties and wear resistance. Hardness and wear resistance of all deposits were improved by heat treatment, but the best candidate was the Nickel-boron (lead), with a hardness over 1100 hk50 after heat treatment and a Taber Wear Index of 6. Scratch testing allowed identifying the damage mechanisms of the coated systems.

Synthesis and Stabilization of Hexagonal Boron Nitride Materials

1993 ◽  
Vol 327 ◽  
Author(s):  
Patrick David ◽  
Alain Mathiot ◽  
Jean-Daniel Lulewicz ◽  
Bruno Narcy
Keyword(s):  
Heat Treatment ◽  
Boron Nitride ◽  
Gas Phase ◽  
Hexagonal Boron Nitride ◽  
Rf Plasma ◽  
Phase Reaction ◽  
Thermal Shield ◽  
High Electrical Resistivity ◽  
Technology Applications ◽  
Post Synthesis

AbstractBoron nitride presents many interesting properties for high temperature applications: high specific modulus, high electrical resistivity, electromagnetic transparency and strong chemical stability. However synthesis and densification by liquid or gas phase reactions (CVD, CVI or plasma processes) required for high technology applications (thermal shield, protective coating, microwave windows) are difficult to bring into play because material characteristics are strongly dependent on elaboration conditions. Boron nitride ultrafine powder synthesized by gas phase reaction in RF plasma (using NH3 and BCh3 at 800-1400°C) and composites obtained using a rapid densification process (vapor phase infiltration using trichloroborazole compound as precursor) have been studied. In both cases post synthesis heat treatment had to be performed in order to get stabilization of the material, and to avoid its hydrolysis. The stability has been related to the physical characteristics of the material. Thermodynamical studies using Gibbs energy minimization calculations were helpful to determine synthesis and heat treatment conditions.

Influence of the Zinc Sublayer Method Production and Heat Treatment on the Microhardness of the Composite Ni-Al2O3 Coating Deposited on the 5754 Aluminium Alloy

2014 ◽  
Vol 59 (1) ◽  
pp. 355-358
Author(s):  
M. Karaś ◽  
M. Nowak ◽  
M. Opyrchał ◽  
M. Bigaj ◽  
A. Najder
Keyword(s):  
Heat Treatment ◽  
Aluminium Alloy ◽  
Thermal Shock ◽  
Nickel Coating ◽  
Nickel Sulphate ◽  
Al2o3 Coating ◽  
Nickel Coatings ◽  
Watts Bath ◽  
Before And After ◽  
Zinc Interlayer

Abstract In this study, the effect of zinc interlayer on the adhesion of nickel coatings reinforced with micrometric Al2O3 particles was examined. Nickel coating was applied by electroplating on EN AW - 5754 aluminium alloy using Watts bath at a concentration of 150 g/l of nickel sulphate with the addition of 50 g/l of Al2O3. The influence of zinc intermediate coating deposited in single, double and triple layers on the adhesion of nickel coating to aluminium substrate was also studied. The adhesion was measured by the thermal shock technique in accordance with PN-EN ISO 2819. The microhardness of nickel coating before and after heat treatment was additionally tested. It was observed that the number of zinc interlayers applied does not significantly affect the adhesion of nickel which is determined by thermal shock. No defect that occurs after the test, such as delamination, blistering or peeling of the coating was registered. Microhardness of the nickel coatings depends on the heat treatment and the amount of zinc in the interlayer. For both single and double zinc interlayer, the microhardness of the nickel coating containing Al2O3 particles increased after heat treatment, but decreased when a triple zinc interlayer was applied.

Marcus-Hush Theory Revealed by Electron Tunneling Through Hexagonal Boron Nitride

2019 ◽  
Author(s):  
Matěj Velický ◽  
Sheng Hu ◽  
Colin R. Woods ◽  
Peter S. Toth ◽  
Viktor Zólyomi ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Boron Nitride ◽  
Electron Tunneling ◽  
Hexagonal Boron Nitride ◽  
Large Body ◽  
Liquid Solution ◽  
Limiting Current ◽  
Electron Transfer Rate Constant ◽  
Electrochemical Parameters ◽  
Voltammetric Measurements

Marcus-Hush theory of electron transfer is one of the pillars of modern electrochemistry with a large body of supporting experimental evidence presented to date. However, some predictions, such as the electrochemical behavior at microdisk electrodes, remain unverified. Herein, we present a study of electron tunneling across a hexagonal boron nitride barrier between a graphite electrode and redox levels in a liquid solution. This was achieved by the fabrication of microdisk electrodes with a typical diameter of 5 µm. Analysis of voltammetric measurements, using two common redox mediators, yielded several electrochemical parameters, including the electron transfer rate constant, limiting current, and transfer coefficient. They show a significant departure from the Butler-Volmer behavior in a clear manifestation of the Marcus-Hush theory of electron transfer. In addition, our system provides a novel experimental platform, which could be applied to address a number of scientific problems such as identification of reaction mechanisms, surface modification, or long-range electron transfer.

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