scholarly journals The Electrochemical Corrosion Properties of PANI/Coal Composites on Magnesium Alloys

2017 ◽  
pp. 4044-4055 ◽  
Author(s):  
Yan Wang ◽  
Keyword(s):  
Magnesium Alloys ◽  
Electrochemical Corrosion ◽  
Corrosion Properties

scholarly journals The Effect of Crystallization and Phase Transformation on the Mechanical and Electrochemical Corrosion Properties of Ni-P Coatings

Coatings ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 447
Author(s):  
Martin Buchtík ◽  
Leoš Doskočil ◽  
Roman Brescher ◽  
Pavel Doležal ◽  
Jiří Másilko ◽  
...  
Keyword(s):  
Phase Transformation ◽  
Crystallite Size ◽  
Electrochemical Corrosion ◽  
Az91 Magnesium Alloy ◽  
Scanning Calorimetry ◽  
Corrosion Properties ◽  
High Phosphorus ◽  
P Content ◽  
Az91 Magnesium ◽  
Increasing Temperature

This paper deals with the study of the crystallization and phase transformation of Ni-P coatings deposited on AZ91 magnesium alloy. Prepared samples were characterized in terms of surface morphology and elemental composition by means of scanning electron microscopy with energy-dispersive spectroscopy analysis. The results of X-ray diffraction analysis and differential scanning calorimetry suggested that increasing the phosphorus content caused Ni-P coatings to develop an amorphous character. The crystallization of Ni was observed at 150, 250, and 300 °C for low-, medium- and high-phosphorus coatings, respectively. The Ni crystallite size increased with increasing temperature and decreasing P content. Conversely, the presence of the Ni3P phase was observed at a maximum peak of 320 °C for the high-phosphorus coating, whereas the crystallization of the Ni3P phase shifted to higher temperatures with decreasing P content. The Ni3P crystallite size increased with increasing temperature and increasing P content. An increase in microhardness due to the arrangement of Ni atoms and Ni3P precipitation was observed. The deposition of as-deposited Ni-P coatings led to an improvement in the corrosion resistance of AZ91. However, the heat treatment of coatings resulted in a deterioration in corrosion properties due to the formation of microcracks.

scholarly journals Effect of Plasma Nitriding Process Conditions on Corrosion Resistance of 440B Martensitic Stainless Steel

2014 ◽  
Vol 8 (3) ◽  
pp. 156-159 ◽  
Author(s):  
Magdalena Łępicka ◽  
Małgorzata Grądzka-Dahlke
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Degradation Products ◽  
Plasma Nitriding ◽  
Electrochemical Corrosion ◽  
Industrial Applications ◽  
Process Conditions ◽  
Corrosion Properties ◽  
Dental Instruments ◽  
Increased Risk

Abstract Martensitic stainless steels are used in a large number of various industrial applications, e.g. molds for plastic injections and glass moldings, automotive components, cutting tools, surgical and dental instruments. The improvement of their tribological and corrosion properties is a problem of high interest especially in medical applications, where patient safety becomes a priority. The paper covers findings from plasma nitrided AISI 440B (PN-EN or DIN X90CrMoV18) stainless steel corrosion resistance studies. Conventionally heat treated and plasma nitrided in N2:H2 reaction gas mixture (50:50, 65:35 and 80:20, respectively) in two different temperature ranges (380 or 450°C) specimens groups were examined. Microscopic observations and electrochemical corrosion tests were performed using a variety of analytical techniques. As obtained findings show, plasma nitriding of AISI 440B stainless steel, regardless of the process temperature, results in reduction of corrosion current density. Nevertheless, applying thermo-chemical process which requires exceeding temperature of about 400°C is not recommended due to increased risk of steel sensitization to intergranular and stress corrosion. According to the results, material ion nitrided in 450°C underwent leaching corrosion processes, which led to significant disproportion in chemical composition of the corroded and corrosion-free areas. The authors suggest further research into corrosion process of plasma nitrided materials and its degradation products.

scholarly journals Composite Layers “MgAl Intermetalic Layer / PVD Coating” Obtained On The AZ91D Magnesium Alloy By Different Hybrid Surface Treatment Methods

2015 ◽  
Vol 60 (2) ◽  
pp. 1031-1035 ◽  
Author(s):  
J. Smolik ◽  
A. Mazurkiewicz ◽  
J. Kacprzyńska-Gołacka ◽  
M. Rydzewski ◽  
M. Szota ◽  
...  
Keyword(s):  
Surface Treatment ◽  
Magnesium Alloys ◽  
Surface Engineering ◽  
Composite Layer ◽  
Electron Beam Evaporation ◽  
Treatment Technology ◽  
Corrosion Properties ◽  
Pvd Coating ◽  
Composite Layers ◽  
Coating Composite

Abstract Magnesium alloys have very interesting physical properties which make them ‘materials of the future’ for tools and machine components in many industry areas. However, very low corrosion and tribological resistance of magnesium alloys hampers the implementation of this material in the industry. One of the methods to improve the properties of magnesium alloys is the application of the solutions of surface engineering like hybrid technologies. In this paper, the authors compare the tribological and corrosion properties of two types of “MgAlitermetalic / PVD coating” composite layers obtained by two different hybrid surface treatment technologies. In the first configuration, the “MgAlitermetalic / PVD coating” composite layer was obtained by multisource hybrid surface treatment technology combining magnetron sputtering (MS), arc evaporation (AE) and vacuum heating methods. The second type of a composite layer was prepared using a hybrid technology combined with a diffusion treatment process in Al-powder and the electron beam evaporation (EB) method. The authors conclude, that even though the application of „MgAlitermetalic / PVD coating” composite layers can be an effective solution to increase the abrasive wear resistance of magnesium alloys, it is not a good solution to increase its corrosion resistance.

The effect of extension twinning on the electrochemical corrosion properties of Mg–Y alloys

2015 ◽  
Vol 618 ◽  
pp. 44-48 ◽  
Author(s):  
Guodong Zou ◽  
Qiuming Peng ◽  
Yanan Wang ◽  
Baozhong Liu
Keyword(s):  
Electrochemical Corrosion ◽  
Corrosion Properties

Microstructure, Mechanical and Corrosion Properties of UNS 32205 Duplex Stainless Steel Weldment Joints by Multipass FCAW

2021 ◽  
Vol 58 (6) ◽  
pp. 332-353
Author(s):  
A. Kisasoz ◽  
M. Tümer ◽  
A. Karaaslan
Keyword(s):  
Arc Welding ◽  
Weld Seam ◽  
Electrochemical Corrosion ◽  
Charpy Impact ◽  
Corrosion Properties ◽  
Cored Wire ◽  
Weld Joints ◽  
Flux Cored Arc Welding ◽  
Mechanical And Corrosion Properties ◽  
Stainless Steel Weldment

Abstract In this study, the effect of multipass welding on the microstructure, mechanical and corrosion properties of the UNS 32205 duplex stainless steels (DSS) is investigated. The UNS 32205 DSS is welded in 3 or 7 passes by flux-cored arc welding (FCAW) using E2209 T1 – 1/4 flux cored wire. The weldments are characterized by light optical microscopy (LOM), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), Feritscope analysis, Charpy impact tests and electrochemical corrosion tests. The results suggest that the multipass FCAW process induces the formation of γ2 in the weld seam. The mechanical and the corrosion properties of the weld joints are affected by the heat input variation and the phase transformations. Especially, the formation of the γ2 in the weld seam results in a decrease in the corrosion resistance of the joint samples.

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