A Novel Micro-Arc Anodising Process for Aluminium Alloys Containing High Silicon

2009 ◽  
Vol 618-619 ◽  
pp. 279-282
Author(s):  
Zhi Ming Shi ◽  
Ming Xing Zhang
Keyword(s):  
Corrosion Resistance ◽  
High Voltage ◽  
Current Density ◽  
Aluminium Alloys ◽  
Al Alloys ◽  
Alkaline Electrolyte ◽  
Microstructure Examination ◽  
High Silicon ◽  
Highly Porous ◽  
Silicon Particles

Although the anodising process has been widely used in surface treatment of Al alloys, the well known sulphuric acid anodising process produces inhomogeneous and highly porous anodised coatings on Al alloys containing high Si due to the inertness of the silicon particles. The present work reports a novel micro-arc anodising process for such high-silicon aluminium alloys. Uniform and thick anodising coatings can be obtained through an anodising process in an alkaline electrolyte under high voltage and low current density conditions. The microstructure examination in SEM indicates that most pores in the coatings have been sealed during the anodising process, thus post-treatment that is normally needed for the currently used anodising process can be eliminated. The coating is very promising in the improvement of corrosion resistance for cast high-silicon aluminium alloys.

scholarly journals Controlling the Formation of Iron-Bearing Intermetallics in Wrought Al Alloys by Melt Conditioned DC (MC-DC) Casting Technology

2015 ◽  
Vol 828-829 ◽  
pp. 43-47 ◽  
Author(s):  
Hu Tian Li ◽  
J.B. Patel ◽  
H.R. Kotadia ◽  
Z. Fan
Keyword(s):  
Corrosion Resistance ◽  
Aluminium Alloys ◽  
Downstream Processing ◽  
Al Alloys ◽  
Grain Refiner ◽  
Casting Technology ◽  
Negative Effect ◽  
Dc Casting ◽  
Primary Aluminium ◽  
Iron Bearing

With the increasing use of recycled aluminium alloys from the end-of-life products more and more iron is accumulated into the compositions of alloys. Sometimes, recycling causes the iron levels to increase beyond the set target levels for down-stream processing. The only way to deal with this impurity currently in industry is to increase the primary aluminium added to the furnace to dilute the melt and re-add all other elements or cast it for re-melting or extrude it for products that is not surface finish critical or required higher corrosion resistance. Formation of small well dispersed spherical a- or small b- Fe-bearing intermetallics, which can be homogenised for shorter times and has no negative effect on downstream processing, would be promising even if the iron levels are above the targeted compositional limits. In the present paper, fine and dispersed Fe-bearing intermetallics have been achieved by Melt Conditioned DC (MC-DC) casting technology, instead of coarser Fe-bearing intermetallics forming network like morphology in the DC castings with grain refiner additions (DC-GR). This suggests feasibility of an increased tolerance of iron levels by melt conditioned DC casting technology.

scholarly journals Pit nucleation on as-cast aluminiuim alloy AW-5083 in 0.01M NaCl

2011 ◽  
Vol 47 (1) ◽  
pp. 79-87 ◽  
Author(s):  
N. Dolic ◽  
J. Malina ◽  
A. Begic-Hadzipasic
Keyword(s):  
Corrosion Resistance ◽  
Aluminium Alloys ◽  
High Strength ◽  
Al Alloys ◽  
Surface Oxide Layer ◽  
Good Corrosion Resistance ◽  
Weight Saving ◽  
Wide Range ◽  
Pit Nucleation ◽  
Cast Condition

The use of aluminium alloys in a wide range of technical applications is related mostly to the two facts: they facilitate weight saving of final products (if compared to the steel) and they are prone to spontaneous passivity due to the coherent surface oxide layer which impedes further reaction of aluminium with the environment. Among the commercial Al alloys, EN AW-5083 alloy is a representative non-heat treatable Al-Mg based alloy which possesses many interesting characteristics as a structural material, such as low price, moderately high strength, high formability in conjunction with superplasticity and good corrosion resistance in marine atmospheres. Aiming to enhance the knowledge of possible interactions of studied alloy EN AW-5083 in as-cast condition with chloride media, electrochemical measurements were used to follow the pitting behaviour in 0.01 M NaCl. The results of tests have shown that susceptibility of alloy to pitting corrosion is strongly influenced by the microstructural constituents of the alloy in as-cast condition.

CORROSIRON

Alloy Digest ◽  
1953 ◽  
Vol 2 (10) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Cast Iron ◽  
Physical Properties ◽  
Tensile Properties ◽  
Corrosion Resistant ◽  
High Silicon

Abstract CORROSIRON is a high silicon corrosion resistant cast iron containing 14.5% Silicon. This datasheet provides information on composition, physical properties, hardness, and tensile properties. It also includes information on corrosion resistance as well as machining and joining. Filing Code: CI-3. Producer or source: Pacific Foundry Company Ltd.

DURICHLOR 51M

Alloy Digest ◽  
1996 ◽  
Vol 45 (4) ◽  
Keyword(s):  
Compressive Strength ◽  
Corrosion Resistance ◽  
Hydrochloric Acid ◽  
Physical Properties ◽  
Tensile Properties ◽  
Silicon Iron ◽  
Chlorine Gas ◽  
High Silicon

Abstract Durichlor 51M is a high silicon iron for corrosive services, especially in the handling of hydrochloric acid in all concentrations. It is also very resistant to most chlorine gas and many destructive chloride-containing solutions. The alloy is treated at melting by argon ladle degassing. This datasheet provides information on composition, physical properties, hardness, tensile properties, and compressive strength. It also includes information on corrosion resistance as well as machining and joining. Filing Code: FE-109. Producer or source: The Duriron Company Inc.

DURICHLOR 51 SUPERCHLOR

Alloy Digest ◽  
1993 ◽  
Vol 42 (1) ◽  
Keyword(s):  
Compressive Strength ◽  
Corrosion Resistance ◽  
Hydrochloric Acid ◽  
Physical Properties ◽  
Tensile Properties ◽  
Silicon Iron ◽  
Chlorine Gas ◽  
High Silicon

Abstract DURICHLOR 51 SUPERCHLOR is a vacuum treated high silicon iron for corrosive services, especially in the handling of hydrochloric acid in all concentrations. It is also very resistant to most chlorine gas and many destructive chloride-containing solutions. This datasheet provides information on composition, physical properties, hardness, tensile properties, and compressive strength. It also includes information on corrosion resistance as well as machining and joining. Filing Code: FE-98. Producer or source: The Duriron Company Inc.

ALUMINUM A413.0

Alloy Digest ◽  
1984 ◽  
Vol 33 (5) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Shear Strength ◽  
Physical Properties ◽  
Tensile Properties ◽  
Base Alloy ◽  
Heat Treating ◽  
Aluminum Base Alloy ◽  
Thin Walled ◽  
High Silicon ◽  
Aluminum Base

Abstract ALUMINUM A413.0 is a high-silicon (nominally 12%), aluminum-base alloy. It is recommended for applications where excellent castability and resistance to corrosion are required. Typical uses comprise miscellaneous thin-walled and intricately designed castings for such items as meter cases and automobile fittings. This datasheet provides information on composition, physical properties, elasticity, tensile properties, and shear strength as well as fatigue. It also includes information on corrosion resistance as well as casting, heat treating, machining, and joining. Filing Code: Al-251. Producer or source: Various aluminum companies.

URANUS S1

Alloy Digest ◽  
1999 ◽  
Vol 48 (7) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Shear Strength ◽  
High Temperature ◽  
Nitric Acid ◽  
Physical Properties ◽  
Tensile Properties ◽  
Intergranular Corrosion ◽  
Heat Treating ◽  
Temperature Performance ◽  
High Silicon

Abstract URANUS S1 is the development of 15 years research into alloys containing high silicon contents (4% here) to resist the transpassive intergranular corrosion from such chemicals as concentrated nitric acid. This datasheet provides information on composition, physical properties, elasticity, tensile properties, and shear strength. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, and joining. Filing Code: SS-751. Producer or source: Cruesot-Marrel.

scholarly journals Structure, Corrosion Resistance, Mechanical and Tribological Properties of ZrB2 and Zr-B-N Coatings

Metals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1194
Author(s):  
Philipp Kiryukhantsev-Korneev ◽  
Alina Sytchenko ◽  
Yuriy Kaplanskii ◽  
Alexander Sheveyko ◽  
Stepan Vorotilo ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Tribological Properties ◽  
Current Density ◽  
Corrosion Current Density ◽  
Elastic Recovery ◽  
Optical Emission ◽  
Corrosion Current ◽  
Impact Testing ◽  
Total Oxidation ◽  
Mechanical And Tribological Properties

The coatings ZrB2 and Zr-B-N were deposited by magnetron sputtering of ZrB2 target in Ar and Ar–15%N2 atmospheres. The structure and properties of the coatings were investigated via scanning and transmission electron microscopy, energy dispersion analysis, optical profilometry, glowing discharge optical emission spectroscopy and X-ray diffraction analysis. Mechanical and tribological properties of the coatings were investigated using nanoindentation, “pin-on-disc” tribological testing and “ball-on-plate” impact testing. Free corrosion potential and corrosion current density were measured by electrochemical testing in 1N H2SO4 and 3.5%NaCl solutions. The oxidation resistance of the coatings was investigated in the 600–800 °С temperature interval. The coatings deposited in Ar contained 4–11 nm grains of the h-ZrB2 phase along with free boron. Nitrogen-containing coatings consisted of finer crystals (1–4 nm) of h-ZrB2, separated by interlayers of amorphous a-BN. Both types of coatings featured hardness of 22–23 GPa; however, the introduction of nitrogen decreased the coating’s elastic modulus from 342 to 266 GPa and increased the elastic recovery from 62 to 72%, which enhanced the wear resistance of the coatings. N-doped coatings demonstrated a relatively low friction coefficient of 0.4 and a specific wear rate of ~1.3 × 10−6 mm3N−1m−1. Electrochemical investigations revealed that the introduction of nitrogen into the coatings resulted in the decrease of corrosion current density in 3.5% NaCl and 1N H2SO4 solution up to 3.5 and 5 times, correspondingly. The superior corrosion resistance of Zr-В-N coatings was related to the finer grains size and increased volume of the BN phase. The samples ZrB2 and Zr-B-N resisted oxidation at 600 °C. N-free coatings resisted oxidation (up to 800 °С) and the diffusion of metallic elements from the substrate better. In contrast, Zr-B-N coatings experienced total oxidation and formed loose oxide layers, which could be easily removed from the substrate.

scholarly journals Analysis of Electric Field and Current Density for Different Electrode Configuration of XLPE Insulation

2018 ◽  
Vol 7 (3.36) ◽  
pp. 127 ◽  
Author(s):  
Nishanthi Sunthrasakaran ◽  
Nor Akmal Mohd Jamail ◽  
Qamarul Ezani Kamarudin ◽  
Sujeetha Gunabalan
Keyword(s):  
Electric Field ◽  
Power System ◽  
Field Distribution ◽  
High Voltage ◽  
Current Density ◽  
Electric Field Distribution ◽  
Electrical Power ◽  
High Electric Field ◽  
Electrode Configuration ◽  
Maximum Electric Field

The most important aspect influencing the circumstance and characteristics of electrical discharges is the distribution of electric field in the gap of electrodes. The study of discharge performance requires details on the variation of maximum electric field around the electrode. In electrical power system, the insulation of high voltage power system usually subjected with high electric field. The high electric field causes the degradation performance of insulation and electrical breakdown start to occur. Generally, the standard sphere gaps widely used for protective device in electrical power equipment. This project is study about the electric field distribution and current density for different electrode configuration with XLPE barrier. Hence, the different electrode configuration influences the electric field distribution. This project mainly involves the simulation in order to evaluate the maximum electric field for different electrode configuration. Finite Element Method (FEM) software has been used in this project to perform the simulation. This project also discusses the breakdown characteristics of the XLPE. The accurate evaluation of electric field distribution and maximum electric field is an essential for the determination of discharge behavior of high voltage apparatus and components. The degree of uniformity is very low for pointed rod-plane when compared to other two electrode configurations. The non- uniform electric distribution creates electrical stress within the surface of dielectric barrier. As a conclusion, when the gap distance between the electrodes increase the electric field decrease.  

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