Radiometric Study of Phosphate Coatings Formed on Steel in Pretreatment Baths★

CORROSION ◽  
1954 ◽  
Vol 10 (9) ◽  
pp. 285-288 ◽  
Author(s):  
THOMAS F. BOYD ◽  
MICHAEL GALAN ◽  
LEONARD MARKOWITZ
Keyword(s):  
Phosphoric Acid ◽  
Sodium Nitrite ◽  
Sodium Phosphate ◽  
Diammonium Phosphate ◽  
Phosphate Coating ◽  
Sodium Dichromate ◽  
Corrosion Resistant ◽  
Phosphate Coatings ◽  
Corrosion Resistant Coatings ◽  
Sodium Phosphates

Abstract An investigation has been made of the amount of phosphate coating formed on steel by various rustinhibiting solutions. The treatments used were phosphoric acid, phosphoric acid with sodium dichromate and sodium nitrite with diammonium phosphate and with sodium phosphates. No correlation was found between the amount of phosphate coating formed and corrosion resistance. The nature of the coating appears to be the significant factor. The most corrosion resistant coatings were formed by diammonium phosphate-sodium nitrite and sodium phosphate-sodium nitrite treatments, the least by phosphoric acid alone.

Effect of Sodium Nitrite Addition on the Corrosion Resistance of Manganese Phosphate Coating

2020 ◽  
Vol 25 (3) ◽  
pp. 43-50
Author(s):  
Kyong-Sub Min
Keyword(s):  
Corrosion Resistance ◽  
Sodium Nitrite ◽  
Coating Layer ◽  
Phosphate Coating ◽  
Nacl Solution ◽  
Cross Sectional ◽  
Manganese Phosphate ◽  
Eds Analysis ◽  
Phosphate Coatings ◽  
Main Components

This paper describes an effective metal finishing technology for obtaining manganese phosphate coatings on steel. In this study, the effect of sodium nitrite addition on the corrosion resistance of a manganese phosphate coating was investigated. The microstructure, surface morphology, and chemical composition were analyzed by FE-SEM, EDS, and XRD, while the cross-sectional images and thickness of the coating layer were analyzed by FIB. According to the results of the EDS analysis, the main components of the manganese phosphate coating were C, O, P, Mn, and Fe. The XRD results showed that (Mn,Fe)5H2(PO4)4 4H2O in the manganese phosphate coating layer was formed by a chemical reaction between manganese phosphate and elements in the underlying carbon steel. Additionally, electrochemical polarization testing was carried out in order to evaluate the corrosion protection properties of the manganese phosphate coating in a 3.5 wt.% NaCl solution. The corrosion resistance of the phosphate coating was remarkably improved by adding sodium nitrite.

Physical, Chemical, and Crystallographic Characterization of Anodic Coatings on High Strength Aluminum Base Alloys

1976 ◽  
Vol 34 ◽  
pp. 636-637
Author(s):  
R. E. Herfert ◽  
N. T. McDevitt
Keyword(s):  
Sulfuric Acid ◽  
Salt Spray ◽  
High Strength ◽  
Environmental Stability ◽  
Anodic Films ◽  
Sodium Dichromate ◽  
Corrosion Resistant ◽  
Aerospace Applications ◽  
Bond Strengths ◽  
Adhesive Bonded Joints

Durability of adhesive bonded joints in moisture and salt spray environments is essential to USAF aircraft. Structural bonding technology for aerospace applications has depended for many years on the preparation of aluminum surfaces by a sulfuric acid/sodium dichromate (FPL etch) treatment. Recently, specific thin film anodizing techniques, phosphoric acid, and chromic acid anodizing have been developed which not only provide good initial bond strengths but vastly improved environmental durability. These thin anodic films are in contrast to the commonly used thick anodic films such as the sulfuric acid or "hard" sulfuric acid anodic films which are highly corrosion resistant in themselves, but which do not provide good initial bond strengths, particularly in low temperature peel.The objective of this study was to determine the characteristics of anodic films on aluminum alloys that make them corrosion resistant. The chemical composition, physical morphology and structure, and mechanical properties of the thin oxide films were to be defined and correlated with the environmental stability of these surfaces in humidity and salt spray. It is anticipated that anodic film characteristics and corrosion resistance will vary with the anodizing processing conditions.

Functional protective coatings of nickel-based alloys

2019 ◽  
pp. 110-114
Author(s):  
D. A. Gerashchenkov ◽  
T. I. Bobkova ◽  
A. F. Vasiliev ◽  
P. A. Kuznetsov ◽  
E. A. Samodelkin ◽  
...  
Keyword(s):  
Environmental Influence ◽  
Protective Coatings ◽  
Cold Gas Dynamic Spraying ◽  
Functional Elements ◽  
Corrosion Resistant ◽  
Gas Dynamic ◽  
Precision Alloy ◽  
Wear And Corrosion ◽  
High Level ◽  
Corrosion Resistant Coatings

A composition of a precision alloy based on the Ni–Cr–Mo system for wear and corrosion-resistant coatings by supersonic cold gas dynamic spraying has been developed. The optimum coatings composition provides high level of operational properties; its application is very promising for protection of structural and functional elements of marine equipment from aggressive environmental influence.

A Study on Mechanical and Tribological Properties of Hot Pressed Al2O3/ZrO2/h-BN/TiO2 Composites

2011 ◽  
Vol 695 ◽  
pp. 417-420 ◽  
Author(s):  
Hyun Hwi Lee ◽  
Seung Ho Kim ◽  
Bhupendra Joshi ◽  
Soo Wohn Lee
Keyword(s):  
Tribological Properties ◽  
Ceramic Composite ◽  
Elevated Temperatures ◽  
Cutting Tools ◽  
High Hardness ◽  
High Melting Point ◽  
Corrosion Resistant ◽  
Mechanical And Tribological Properties ◽  
Chemical Inertness ◽  
Corrosion Resistant Coatings

Oxide ceramics such as alumina and zirconia are industrially utilized as cutting tools, a variety of bearings, biomaterials, and thermal and corrosion-resistant coatings due to their high hardness, chemical inertness, high melting point, and ability to retain mechanical strength at elevated temperatures. In this research, the effect of other ceramic additives (TiO2) and h-BN within alumina(α-Al2O3) and yttria-stabilized tetragonal (Y-TZP) composite was studied with respect to the mechanical and tribological properties. The lowest coefficient of frction of 0.45 was observed for the ZTA ceramic composite with hBN-TiO2. The highest hardness, fracture toughness and flexural strength were obtained as 15.7GPa, 5.2MPam-1/2, 712MPa, respectively.

(Invited) Corrosion Resistant Coatings for PEM Bipolar Plates, Current Collectors, and PTL’s

2021 ◽  
Vol MA2021-02 (37) ◽  
pp. 1112-1112
Author(s):  
Ton Hurkmans ◽  
Frank Schuivens ◽  
Joris Ummels ◽  
Gerry van der Kolk ◽  
Roel Bosch
Keyword(s):  
Bipolar Plates ◽  
Corrosion Resistant ◽  
Current Collectors ◽  
Corrosion Resistant Coatings

Corrosion resistant metal-ceramic composite coatings for tribological applications

2021 ◽  
pp. 1-34
Author(s):  
Peter Renner ◽  
Swarn Jha ◽  
Yan Chen ◽  
Tariq Chagouri ◽  
Serge Kazadi ◽  
...  
Keyword(s):  
Ceramic Composite ◽  
Low Cost ◽  
Composite Coatings ◽  
Salt Spray ◽  
Extreme Environments ◽  
Safe Procedure ◽  
Corrosion Resistant ◽  
Wide Range ◽  
Metal Ceramic ◽  
Corrosion Resistant Coatings

Abstract Effective design of corrosion-resistant coatings is critical for the protection of metals and alloys. Many state-of-the-art corrosion-resistant coatings are unable to satisfy the challenges in extreme environments for tribological applications, such as elevated or cryogenic temperatures, high mechanical loads and impacts, severe wear, chemical attack, or a combination of these. The nature of challenging conditions demands that coatings have high corrosion and wear resistance, sustained friction control, and maintain surface integrity. In this research, multi-performance metal-ceramic composite coatings were developed for applications in harsh environments. These coatings were developed with an easy to fabricate, low-cost, and safe procedure. The coating consisted of boron nitride, graphite, silicon carbide, and transition metals such as chromium or nickel using epoxy as vehicle and bonding agent. Salt spray corrosion tests showed that 1010 carbon steel (1/4 hard temper) substrates lost 20-100× more mass than the coatings. The potentiodynamic polarization study showed better performance of the coatings by seven orders of magnitude in terms of corrosion relative to the substrate. Additionally, the corrosion rates of the coatings with Ni as an additive were five orders of magnitude lower than reported. The coefficient of friction of coatings was as low as 0.1, five to six times lower than that of epoxy and lower than a wide range of epoxy resin-based coatings found in literature. Coatings developed here exhibited potential in applications in challenging environments for tribological applications.

Bioactivity, Wear and Corrosion Resistant Properties of Rare Earth/Calcium Phosphate Composite Coatings

2008 ◽  
Vol 368-372 ◽  
pp. 1194-1197 ◽  
Author(s):  
Chen Ma ◽  
Ying Hui Wang ◽  
Mu Qin Li ◽  
Li Jie Qu
Keyword(s):  
Rare Earth ◽  
Calcium Phosphate ◽  
Composite Coatings ◽  
Xrd Analysis ◽  
Wear Properties ◽  
Corrosion Resistant ◽  
Phosphate Coatings ◽  
Wear And Corrosion ◽  
Micro Arc Oxidation ◽  
Calcium Phosphate Coatings

Rare earth/calcium phosphate composite coatings were fabricated on the surface of Ti-6Al-4V by micro-arc oxidation (MAO) technique. The wear properties and corrosion resistant of rare earth/ calcium phosphate composite coatings in the simulated body fluid (SBF) have been investigated and the bioactivity of the composite coatings were evaluated. The results show that the friction coefficient of the composite coatings in the SBF is only 0.15~0.18 and the anode polarization potential of the coating has been obviously enhanced about 0.18V compared with that of coatings of calcium phosphate coatings. So the composite coatings have excellent wear and corrosion resistant properties. XRD analysis indicates that the composite coatings can induce hydroxyapatite to form on its surface after soaked in SBF for 9d, which shows that the composite coatings own good bioactivity.

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