Vitreous Enamel Coating on Steel Substrates

2009 ◽  
Vol 147-149 ◽  
pp. 856-860 ◽  
Author(s):  
Kamila Hrabovská ◽  
Jitka Podjuklová ◽  
Karla Barčová ◽  
Lenka Dobrovodská ◽  
Katerina Pelikánová
Keyword(s):  
Enamel Coating ◽  
Steel Substrate ◽  
Substrate Surface ◽  
Phase Interface ◽  
Adhesive Properties ◽  
Vitreous Enamel ◽  
Enamel Slip ◽  
Pre Treatment ◽  
Steel Substrates

Vitreous enamel is a glassy coating formed on a metal substrate by firing at temperatures above 800 °C. The quality of vitreous enamel coating depends on the pre-treatment of the steel substrate surface and the quality of enamel slip. The main aim of this study was to characterize the composition of the steel substrate surface after firing with double finish, to explain the effect of steel substrate surface pre-treatment (blasting, acid pickling) on forming the phase interface of the steel substrate – vitreous coating system, and on its final microhardness, fracture strength and the adhesive properties of the coating. To achieve these aims, the following experimental methods were used: Mössbauer spectroscopy, X-ray diffraction, electron analyzer, and EDAX. Based on the chemical composition of the initial enamel slip and the firing technology, the metal - enamel system interface exhibited various ratios of layers of magnetite, hematite, nonstoichiometric wüstite, and crystals of faylite. The measuring results indicate that the quality and age of enamel slip influences the brittle fracture properties of vitreous enamel coating.

scholarly journals Design of Deterministic Microstructures as Substrate Pre-Treatment for CVD Diamond Coating

Surfaces ◽  
2019 ◽  
Vol 2 (3) ◽  
pp. 497-519
Author(s):  
Richard Börner ◽  
Michael Penzel ◽  
Thomas Junge ◽  
Andreas Schubert
Keyword(s):  
Substrate Surface ◽  
Chemical Vapor ◽  
Cvd Diamond ◽  
Functional Surface ◽  
Cooling Process ◽  
Finite Elements Analysis ◽  
Pre Treatment ◽  
Cvd Diamond Coating ◽  
Steel Substrates ◽  
Suitable Process

The coating of highly stressed components with chemical vapor deposition (CVD) diamond can extend their lifetime. In particular, the combination of steel substrates with diamond layers would find many applications in industrial production. However, there are some challenges, for example, the high mismatch in the thermal expansion between steel and diamond, which commonly leads to the delamination of the coating. Thus, a pre-treatment of the substrate surface is needed. Particle blasting has been established in some studies as a suitable process. However, apart from particle residues in the surface of the substrate, these surfaces have a stochastic character, which limits their reproducibility and modification options. This paper presents some instructions for the recording and derivation of defined properties of those surfaces. The conversion of characteristic surface features into quantitative process parameters could serve as the foundation for the manufacturing of deterministic microstructures, especially those produced by ultrasonic vibration superimposed machining. This should increase the reproducibility and the possibilities of the modification with regard to the structural shaping of the functional surface. The design was developed using both a kinematic surface simulation tool as well as a finite elements analysis for the cooling process of the coating–substrate–composite. A high accordance with real finished surfaces was achieved.

scholarly journals Effect of Surface Pre-Treatment on Adhesive Strength of Multi-Component Vacuum-Arc Coatings

2020 ◽  
Keyword(s):  
Crystal Lattice ◽  
Adhesive Strength ◽  
Substrate Surface ◽  
Lattice Parameter ◽  
Vacuum Arc ◽  
Surface Pretreatment ◽  
Vacuum Arc Remelting ◽  
Polished Stainless Steel ◽  
Pre Treatment ◽  
Steel Substrates

The results of investigations of multi-component nanostructured coatings of (TiAlSiY)N/CrN type are presented. The influence of different variants of substrate surface pretreatment on adhesive strength and hardness of coatings was studied. Pre-treatment of samples was carried out in plasma of two-stage gas discharge according to various technological schemes. Except for ion-plasma purification, some samples were pretreated with a sublayer of chromium within 5 minutes. The coatings were formed by a vacuum-arc deposition method at simultaneous spraying of two cathode targets. The first cathode is made of chromium, and the second cathode is made of multicomponent Ti - Al - Si - Y alloy obtained by vacuum-arc remelting of powder mixture of the mentioned elements. The coatings were deposited on polished stainless-steel substrates at negative 280 V bias potential. The geometry of the unit and its elements, as well as technological characteristics of the processes of evaporation-condensation were selected so that at a speed of rotation of samples 8 revolutions per minute the formation of the coating with a total thickness of about 9.0 microns occurred in approximately 60 minutes. The analysis of the composition of the coatings shows that the content of elements in the coating differs greatly from the content of elements in the sprayed cathodes. The X-ray diffractometry has shown that all deposition modes are characterized by the formation of phases with cubic (fcc) crystal lattice in both phase layers of multilayer coatings. In the layers formed at spraying of TiAlSiY alloy, a multi-element disordered solid solution (TiAlSiY)N with a crystal lattice of NaCl type and a lattice parameter of 0.4241 nm, as well as chromium mononitride CrN with a lattice parameter of 0.4161 nm, is determined. It has been established that preliminary formation of a chromium sublayer on the substrate leads to significant changes in adhesive strength of multi-component coatings compared to coatings without a sublayer.

Advanced Technologies for Determination of Surface Cleanliness

2014 ◽  
Vol 11 (1) ◽  
pp. 16-19 ◽  
Author(s):  
Jan Kudlacek ◽  
Petr Chabera
Keyword(s):  
Surface Treatment ◽  
Substrate Surface ◽  
Modern Method ◽  
Surface Pretreatment ◽  
Advanced Technologies ◽  
Pre Treatment ◽  
High Utility ◽  
Correct Application

Abstract For high utility value of products is significant quality of surface treatment. Among the processes that most affect the quality of surface treatment are mainly surface pretreatment processes, namely processes of cleaning (degreasing). This article is devoted to quality control after surface pre-treatment. It mainly deals with the modern method for detecting surface contamination grease based on fluorescence methods. Impurities such as grease, oil and other have characteristic fluorescence after illumination by UV source. This principle can be used to determine the purity of the substrate surface, thereby ensuring the quality of the surface. Surface cleanliness is very important factor for the correct application of subsequent technological processes.

scholarly journals Experimental Investigation on Mechanical Properties of TiAlN Thin Films Deposited by RF Magnetron Sputtering

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
L. Natrayan ◽  
S. Balaji ◽  
G. Bharathiraja ◽  
S. Kaliappan ◽  
Dhinakaran Veeman ◽  
...  
Keyword(s):  
Thin Films ◽  
Mechanical Properties ◽  
Wear Resistance ◽  
Magnetron Sputtering ◽  
Steel Substrate ◽  
Substrate Surface ◽  
Wear Test ◽  
Rf Magnetron Sputtering ◽  
Pin On Disk ◽  
Steel Substrates

The mechanical properties of TiAlN deposited on the steel are explained in this study. Thin films are deposited by RF magnetron sputtering on the steel substrates to improve the wear resistance and hardness of the samples. Due to their improved microstructure and nanograins, the nanofilms have improved the mechanical properties of the steel substrate surface. The thin film deposited has improved the wear resistance by 80% and has improved the hardness by 95%. The deposited thin films are tested for hardness by nanoindentation and wear test by the pin-on-disk test. SEM has tested films for their microstructure and adhesion by nanoscratch test.

Comparison of Different Substrate Pre-Treatments on the Quality of GaN Film Growth on 6H-, 4H-, and 3C-SiC

2000 ◽  
Vol 622 ◽  
Author(s):  
K. H. Lee ◽  
M. H. Hong ◽  
K. Teker ◽  
C. Jacob ◽  
P. Pirouz
Keyword(s):  
Buffer Layer ◽  
Film Growth ◽  
Lattice Mismatch ◽  
Substrate Surface ◽  
Substrate Material ◽  
Cross Sectional ◽  
Pre Treatment ◽  
Film Substrate ◽  
Gan Film

ABSTRACTTogether with sapphire, SiC is the most common substrate material for GaN epitaxial growth. In fact, SiC has advantages over sapphire because of its better thermal conductivity and lower film substrate lattice mismatch (∼3.5%). However, nucleation of GaN on SiC is rather difficult because of the low surface energy of SiC and the sensitivity of substrate preparation. This latter point makes it essential to use a very careful cleaning step, and also to pre-treat the substrate surface by growing a thick buffer layer of AlN at a relatively high temperature. In this study, several pre-treatment steps of SiC for GaN deposition were tested including (a) nitration with NH3 for 0.5-20 minutes, (b) pre-adsorption of trimethyl gallium (TMG) or trimethyl aluminum (TMA) for 0.5-5 minutes, and (c) deposition of an AlN buffer layer at ∼1150°C. After each pre-treatment, GaN was deposited by MOCVD using dilute H2(Ar+12%H2), NH3 and TMG. All the films were characterized by XRD and cross-sectional TEM. After nitration of SiC, the deposited GaN film was found to be polycrystalline. In case of pre-adsorption of TMG, epitaxial but island-like GaN formed on the substrate. In the third case, with an ultra-thin (∼1.5nm) coverage of AlN on SiC (by pre-adsorption of TMA or by 50 seconds deposition of AlN), GaN epilayers were successfully deposited on SiC. However, when AlN was deposited for longer than 3 minutes (up to 10 minutes), only polycrystalline GaN was obtained. With this technique of covering the surface with an ultra-thin layer of AlN, epitaxial GaN has been successfully deposited on 6H-SiC (0001), on 4H-SiC(0001), and on 3C-SiC/Si(111) substrates. The effect of the different pre-treatments of SiC on the quality of the deposited GaN films will be discussed and compared, and the optimal conditions for GaN deposition for each substrate will be presented.

Thin Metal Film Adhesion Studies on GaAs

1986 ◽  
Vol 77 ◽  
Author(s):  
T. T. Bardin ◽  
J. G. Pronko ◽  
D. K. Kinell
Keyword(s):  
Ion Beam ◽  
Substrate Surface ◽  
Surface Preparation ◽  
Thin Metal Film ◽  
Optimum Conditions ◽  
Adhesive Properties ◽  
Ion Beam Mixing ◽  
Film Adhesion ◽  
Thin Film Adhesion

ABSTRACTComparative thin film adhesion studies were performed on GaAs substrates using Au or Au-Ni-Ge, metallization materials. The influence of parameters such as crystal orientation, substrate surface preparation, deposition vacuum conditions, thickness and composition of films, and post-evaporative treatment such as ion-beam mixing and thermal annealing, on film adhesion was considered. The quality of the adhesion bond was measured using Scotch tape tests and a Sebastian adhesion tester. Film interfaces were characterized using AES, XPS, and RBS techniques. The results indicate that the most important factors dominating the quality of adhesion were surface preparation and the deposition vacuum conditions. Films deposited under optimum conditions were found to adhere so well that the GaAs crystal would fracture before the film would pull free of the substrate. The influence of ion beam mixing on the quality of adhesion was tested and only in the cases of depositions under the less optimum conditions, where the adhesion was poor, could an improvement be made in the adhesive properties.

Characterization of homoepitaxial diamond films by Electron microscopy

1991 ◽  
Vol 49 ◽  
pp. 880-881
Author(s):  
D.P. Malta ◽  
S.A. Willard ◽  
R.A. Rudder ◽  
G.C. Hudson ◽  
J.B. Posthill ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Surface Defects ◽  
Substrate Surface ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Polycrystalline Diamond ◽  
Large Degree ◽  
Rf Plasma ◽  
Semiconducting Diamond

Semiconducting diamond films have the potential for use as a material in which to build active electronic devices capable of operating at high temperatures or in high radiation environments. A major goal of current device-related diamond research is to achieve a high quality epitaxial film on an inexpensive, readily available, non-native substrate. One step in the process of achieving this goal is understanding the nucleation and growth processes of diamond films on diamond substrates. Electron microscopy has already proven invaluable for assessing polycrystalline diamond films grown on nonnative surfaces.The quality of the grown diamond film depends on several factors, one of which is the quality of the diamond substrate. Substrates commercially available today have often been found to have scratched surfaces resulting from the polishing process (Fig. 1a). Electron beam-induced current (EBIC) imaging shows that electrically active sub-surface defects can be present to a large degree (Fig. 1c). Growth of homoepitaxial diamond films by rf plasma-enhanced chemical vapor deposition (PECVD) has been found to planarize the scratched substrate surface (Fig. 1b).

Improvement in Gate Dielectric Quality of Ultra Thin a: SiN:H MNS Capacitor by Hydrogen Etching of the Substrate

2002 ◽  
Vol 716 ◽  
Author(s):  
Parag C. Waghmare ◽  
Samadhan B. Patil ◽  
Rajiv O. Dusane ◽  
V.Ramgopal Rao
Keyword(s):  
Silicon Nitride ◽  
Gate Dielectric ◽  
Substrate Surface ◽  
Scaling Limit ◽  
Tunneling Current ◽  
Chemical Vapor ◽  
Poor Performance ◽  
State Density ◽  
Direct Tunneling Current

AbstractTo extend the scaling limit of thermal SiO2, in the ultra thin regime when the direct tunneling current becomes significant, members of our group embarked on a program to explore the potential of silicon nitride as an alternative gate dielectric. Silicon nitride can be deposited using several CVD methods and its properties significantly depend on the method of deposition. Although these CVD methods can give good physical properties, the electrical properties of devices made with CVD silicon nitride show very poor performance related to very poor interface, poor stability, presence of large quantity of bulk traps and high gate leakage current. We have employed the rather newly developed Hot Wire Chemical Vapor Deposition (HWCVD) technique to develop the a:SiN:H material. From the results of large number of optimization experiments we propose the atomic hydrogen of the substrate surface prior to deposition to improve the quality of gate dielectric. Our preliminary results of these efforts show a five times improvement in the fixed charges and interface state density.

Environmental Impact Evaluation of Istanbul Wastewater Treatment and Marine Disposal Systems

1992 ◽  
Vol 25 (9) ◽  
pp. 85-92 ◽  
Author(s):  
I. Ozturk ◽  
T. Zambal ◽  
A. Samsunlu ◽  
E. Göknel
Keyword(s):  
Water Quality ◽  
Wastewater Treatment ◽  
Environmental Impact ◽  
Quality Parameters ◽  
Sea Of Marmara ◽  
General Evaluation ◽  
Marine Outfall ◽  
Secondary Stage ◽  
Pre Treatment

Metropolitan Istanbul Wastewater Treatment System contains 14 marine outfalls, seven of which include secondary stage biological treatment processes. The others have only mechanical treatment units including bar screens and grit chambers. Only one mechanical pre-treatment and marine disposal system, Yenikapi plant, has been operated since 1988 among these 14 plants and six of them are ready for construction. In this paper, the environmental impact of Yenikapi pretreatment and marine disposal system on the water quality of the Bosphorus and the Sea of Marmara has been investigated. Long term water quality measurements which were performed in pre-and post-dischange applications have been evaluated. Water quality parameters including pH, DO, BODs, TKN, P and total coliforms were measured at various sampling stations around the discharge points. A general evaluation of marine outfall systems to be constructed in the scope of Istanbul wastewater treatment project, on the water quality of the Sea of Marmara and the Bosphorus has been presented.

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