DOCSLIB.ORG

Effect of Temperature of Oxalic Acid on the Fabrication of Porous Anodic Alumina from Al-Mn Alloys

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Effect of Temperature of Oxalic Acid on the Fabrication of Porous Anodic Alumina from Al-Mn Alloys Research Article Effect of Temperature of Oxalic Acid on the Fabrication of Porous Anodic Alumina from Al-Mn Alloys C. H. Voon, M. N. Derman, U. Hashim, K. R. Ahmad, and K. L. Foo Institute of Nanoelectronic Engineering, Universiti Malaysia Perlis, Seriab, 01000 Kangar, Perlis, Malaysia Correspondence should be addressed to C. H. Voon; david [email protected] Received 30 December 2012; Accepted 12 April 2013 Academic Editor: Lian Gao Copyright © 2013 C. H. Voon et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The influence of temperature of oxalic acid on the formation of well-ordered porous anodic alumina on Al-0.5 wt% Mn alloyswas studied. Porous anodic alumina has been produced on Al-0.5 wt% Mn substrate by single-step anodising at 50 V in 0.5 M oxalic acid ∘ ∘ at temperature ranged from 5 Cto25 C for 60 minutes. The steady-state current density increased accordingly with the temperature ∘ of oxalic acid. Hexagonal pore arrangement was formed on porous anodic alumina that was formed in oxalic acid of 5, 10 and 15 C ∘ while disordered porous anodic alumina was formed in oxalic acid of 20 and 25 C. The temperature of oxalic acid did not affect the pore diameter and interpore distance of porous anodic alumina. Both rate of increase of thickness and oxide mass increased steadily with increasing temperature of oxalic acid, but the current efficiency decreased as the temperature of oxalic acid increased due to enhanced oxide dissolution from pore wall. 1. Introduction a two-step anodising method for the synthesis of well- ordered PAA. Since then, owing to the commercial potential Porous anodic alumina (PAA) is a self-organizing porous and scientific significance, there has been an ongoing material. After the confirmation of the classical cell model research effort towards the fabrication of well-ordered PAA. proposed by Keller et al. [1], PAA has attracted enormous Prepatterning methods such as imprint lithography [12–14], attraction as inexpensive template for the fabrication of vari- focused ion beam lithography [15], and electron beam ous nanostructured materials without the need of costly and lithography [16] were also developed for the fabrication of complex lithographic techniques [2–6]. PAA is a suitable tem- well-ordered PAA. These methods involved the formation plate for the synthesis of nanostructured materials because of indented concave periodic patterns on the aluminium itscellparameterssuchasporediameter,interporedistance, substrates prior to the anodising process. These patterns and pore depth can be controlled easily by varying anodising servedasguideforthenucleationandgrowthofwell-ordered conditions [7, 8]. The fabrication of nanostructured materials PAA. Besides, high-field anodising was also proposed as an by template synthesis method employs well-ordered PAA alternative for the synthesis of well-ordered PAA [17]. Critical because well-ordered PAA provides regular pore shape and high anodising potential which is the anodising potential narrow distribution of specific pore diameter and interpore required to induce high current density while preventing distance for the synthesis of nanostructured materials of local current density concentration on the aluminium uniform dimensions. Since the properties of nanostructured surfacewasappliedduringthehigh-fieldanodising. materials are significantly influenced by the dimensions, itis Although many techniques for the synthesis of well- important to synthesize nanostructured materials of uniform ordered PAA were reported, these techniques employed dimensions [6, 9, 10]. high purity aluminium (99.99%) substrate as a starting In order to fabricate well-ordered PAA, various material. The cost of high purity aluminium is high and approaches were proposed. First well-ordered PAA was it has limited the commercial potential and applications of realized by Masuda and Fukuda in 1995 [11]. They employ well-ordered PAA in the large-scale template synthesis of 2 nanostructured materials. Therefore there is always a need of the substrates before being subjected to anodising were to find an alternative of high purity aluminium substrate to weighted and recorded. widen the applications of PAA. Compared to high purity Substrates were then anodised under the similar operat- aluminium, the costs of aluminium alloys are relatively low. ing conditions except in oxalic acid of increasing temperature. Thus, anodising of aluminium alloys is a good alternative Lead plate was used as cathode. The distance between the to obtain low-cost template for the synthesis of nanostruc- lead cathode and aluminium anode was 40 mm. Anodising tured materials. However, due to the complexity of the was performed at constant voltage for a sufficient time for anodising of aluminium alloys, there are only a few reports the development of steady-state morphology within the film. on the fabrication of PAA film from aluminium alloy, and Anodising was conducted at constant voltage of 50 V in ∘ ∘ ∘ ∘ ∘ most of these studies are emphasized on the commercially 0.5 M oxalic acid of 5 C, 10 C, 15 C, 20 C, and 25 C. The ∘ available aluminium alloys [18–21]. Commercially available temperature variance was controlled within ±0.5 C. Cur- aluminium alloys normally consist of Si, Fe, Mg, Mn, and Cu rent density-time curve was recorded during the anodising as alloying elements. These alloying elements have different process. The anodised substrates were rinsed with flowing behaviour during the anodising process. They may promote ethanol followed by deionised water and dried. or hinder the fabrication of well-ordered PAA. Furthermore, Three samples of 5 mm × 5 mm in area each were these alloying elements may react among each other before or sectioned from each anodised substrate. The cross-sections of during the anodising process. The study of synthesis of PAA the substrates were observed under SEM. The thickness of the from commercially available aluminium alloy is therefore PAA film was measured by using software JEOL SmileView difficulttobeanalyzedandconcluded. version 2.1. The steady-state structure of PAA beneath the Manganese (Mn) is one of the major alloying elements initially formed irregular structure was revealed by oxide used in aluminium alloys. It is added up to two percent dissolution treatment. A mixture of chromic acid and phos- to enhance the corrosion resistance of aluminium alloys, phoric acid was prepared from 20 g of chromium(VI) oxide especially in 3xxx series. Tothe best of our knowledge, limited and 35 mL of 85 wt% phosphoric acid in 1000 mL of distilled study was reported on the synthesis of PAA from Al-Mn water.Oneanodisedsubstrateof5mm× 5mminareawas alloys [22]. There is a growing interest in the development then subjected to oxide dissolution treatment in a stirred ∘ of economic alternative for the synthesis of well-ordered mixture of chromic acid and phosphoric acid at 70–80 Cfor PAA. The cost of large-scale production of nanostructured eight hours. The substrate was rinsed thoroughly with ethanol materials can be significantly reduced when the well-ordered followedbydistilledwaterandthendried.Themorphologyof PAA is fabricated from aluminium alloys instead of expensive the treated PAA was observed under SEM. Pore diameter and high purity aluminium. The synthesis of well-ordered PAA interpore distance of PAA were measured by using software from Al-Mn alloys is affected by the anodising parameters JEOL SmileView version 2.1. such as temperature of oxalic acid. Thus, the purpose of this To measure the mass of oxide film formed, the same study is to investigate the effect of temperature of oxalic acid solution which was used for oxide dissolution treatment was on the fabrication of well-ordered PAA on Al-Mn alloys. The prepared. The mass of the anodised substrates of 5 mm × results of this study are important in the optimization of 5 mm in area before being subjected to dissolution process anodising parameters for the fabrication of well-ordered PAA was recorded. The anodised substrate was then stirred in the ∘ from Al-Mn alloys. In this context, we report a study of the mixture at 70–80 C for 8 hours. The substrate was rinsed effect of temperature of oxalic acid on the fabrication of well- thoroughly with ethanol and distilled water and then dried. ordered PAA from Al-0.5 wt% Mn alloys. The weight of the respective substrate was recorded. The difference between the weights of substrate before and after being subjeced to the oxide dissolution treatment is the mass 2. Experimental of the PAA, . The current efficiencies of the anodising of substrate of different Mn content were calculated based on To fabricate Al substrate of 0.5 wt% Mn content, high purity the reported literature [23]. The mass of aluminium metal (99.99%) aluminium pellets and Al-20 wt% Mn master alloys converted to oxide, ( ),wasrelatedtomassbalanceover ∘ Al of respective mass were melted at 850 C. The molten mixture the anodised sample in was then poured into a 25 mm diameter stainless steel cylindrical mould. Substrates of 4 mm in thickness were =( ) +( −), sectioned from casting product. To remove the residual stress Al (1) on the substrates that was formed during the sectioning ∘ process, the substrates were annealed at 450 C for four hours andannealedinfurnacetoroomtemperature. in which and arethemassoftheanodisedsample All substrates were ground by using silicon carbide paper before and after anodising, and these values were recorded up to 2000 grit to remove scratches formed on the substrate previously. Current efficiency is defined as the ratio ofthe surfaces during sectioning process. The substrates were then actual amount of current used for oxide formation relative polished by using alumina polishing suspension of 6 m, to the total current passed. Mass of oxide formed, , 1 m, and 0.05 m successively to achieve mirror-like surface. was determined from the difference between the masses of Substrates were degreased by dipping them in a stirred anodised sample before and after oxide dissolution.
Load more

Recommended publications
  • Brazing Compilation of Literature References from 1973 to 1978
    OCTOBER 1979 BRAZING COMPILATION OF LITERATURE REFERENCES FROM 1973 TO 1978. BY J.C. RÖMER N et hf^rlfi rids E norqy R o soa re h \ oundation ECN does not assume any liability with respect to the use of, or for damages resulting from the use of any information, apparatus, method or process disclosed in this document. Netherlands Energy Research Foundation ECN P.O. Box 1 1755 ZG Petf.n(NH) The Netherlands Telephone (0)2246 - 62».. Telex 57211 ECN-7* OCTOBER 1979 BRAZING COMPILATION OF LITERATURE REFERENCES FROM 1973 T01978. BY J.C. ROMER -2- ABSTRACT This report is a compilation of published literature on high temperature brazing covering the period 1973-1978. The references are listed alphabetically with regard to the base material or combination of base materials to be brazed. Trade names are treated as base materials. The report contains approximately 1500 references, of which 300 are to patents. KEYWORDS BRAZING BRAZING ALLOYS FILLER METALS JOINING - 3 CONTENTS ABSTRACT 1. ALUMINIUM 2. ALUMINIUM (FLVXLESS) 3. ALUMINIUM - BERYLLIUM 4. ALUMINIUM/BORON COMPOSITES 5. ALUMINIUM - COPPER 5.1. Aluminium - graphite 5.2. Aluminium - nickel alloys 5.3. Aluminium - niobium 5.4. Aluminium ~ molyldenum 5.5. Aluminium - stainless steel 5.6. Aluminium - steels 5.7. Aluminium - tantalum 5.8. Aluminium - titanium 5.9. Aluminium - tungsten 6. BERYLLIUM 7. BORONNITRIDE• 8. BRASS 8.1. Brass - aluminium 8.2. Brass - steels 9. BRONZE 9.1. Bronze - stainless steels 10. CERAMICS 10.1. Ceramics - metal - 4 - CERMETS 61 11.1. Cermets - stainless steels 62 COBALT 63 COPPER ALLOYS 64 13.1. Copper alloys - brass 68 13.2.
    [Show full text]
  • Isinox Metaltec Private Limited
    +91-8042974287 Isinox Metaltec Private Limited https://www.indiamart.com/isinoxalloys/ Isinox Metaltec Private Limited is one of the renowned names occupied in manufacturing and exporting an inclusive collection of products comprising Aluminium Alloy Wire and Copper Cladding Wire. About Us Incepted in the year 2013, Isinox Metaltec Private Limited is one of the excellent business organization effortlessly engrossed in manufacturing and exporting a range of products which include Aluminium Alloy Wire and Copper Cladding Wire. Made in adherence with the prevailing market set standards, we guarantee that only optimal-class material and different modern tools and machines are used in their improvement procedure. In compliance with the trends and advancements taking place in the market, these are especially applauded. Underneath the path of our mentor Mr. Ravi Bansal, we have finished massive popularity and credibility of our customers. For more information, please visit https://www.indiamart.com/isinoxalloys/profile.html ALUMINIUM ALLOY WIRES P r o d u c t s 5052 Aluminium Alloy Wire Aluminum Alloy Wire Aluminum Alloy TIG Welding 5056 Aluminium Alloy Wire Wire ALUMINUM WELDING WIRE P r o d u c t s Aluminium Alloy Wire for 5052 Aluminum Alloy Wire Water-Bottle Carrier 1050 Aluminum Wire 2011 Aluminium Alloy Wire ALUMINIUM ALLOY WIRE P r o d u c t s 1060 1080 1085 High Quality Aluminium Alloy Wire For Aluminum Wire Used In Refrigerator Grilles Aluminium Alloy Wire For 1120 Aluminium Alloy Wire Clothes Pegs ALUMINUM WIRE P r o d u c t s 5154
    [Show full text]
  • Application of a State Variable Description of Inelastic Deformation to Geological Materials
    APPLICATION OF A STATE VARIABLE DESCRIPTION OF INELASTIC DEFORMATION TO GEOLOGICAL MATERIALS A thesis submitted for the degree of Doctor of Philosophy (University of London) and for the Diploma of University College by Stephen John Covey-Crump Department of Geological Sciences, University College London, Gower Street, London, WC1E 6BT ProQuest Number: 10630768 All rights reserved INFORMATION TO ALL USERS The quality of this reproduction is dependent upon the quality of the copy submitted. In the unlikely event that the author did not send a com plete manuscript and there are missing pages, these will be noted. Also, if material had to be removed, a note will indicate the deletion. uest ProQuest 10630768 Published by ProQuest LLC(2017). Copyright of the Dissertation is held by the Author. All rights reserved. This work is protected against unauthorized copying under Title 17, United States C ode Microform Edition © ProQuest LLC. ProQuest LLC. 789 East Eisenhower Parkway P.O. Box 1346 Ann Arbor, Ml 48106- 1346 2 ABSTRACT The work reported in this thesis is an investigation of the potential for employing non­ steady-state constitutive relations to describe the inelastic deformation properties of rock forming minerals. Attempts to determine generally applicable constitutive equations for inelastic deformation are complicated by the severe path dependence of the deformation response and by the wide range of mechanisms by which that deformation is accomplished. In the geological literature it has been normal practice to circumvent these problems by approximating the deformation as occurring at steady-state. This presents difficulties for the description of deformation by inherently transient mechanisms, for the description of small strain deformation, and for the reliability of extrapolating laboratory mechanical properties to geological deformation conditions.
    [Show full text]
  • Guide to High Performance Alloys
    Table of Contents Alloy Guide 3 The Alloys of Materion Brush Performance Alloys 4 Chemical Composition 6 Alloy Products 6 Physical Properties 8 Product Guide 10 Strip and Wire Temper Designations 11 Strip 12 Strip Product Specifications 13 Spring Bend Limits of Strip Alloys 19 Wire 20 Rod, Bar, Tube and Plate Temper Designations 22 Rod and Bar 22 Tube 26 Plate and Rolled Bar 29 MoldMAX® and PROtherm™ Plastic Tooling Alloys 31 ToughMet® and Alloy 25 Oilfield Products 32 Alloy 25 Drill String Temper (25 DST) 33 BrushCAST® Casting Ingot & Master Alloys 34 Forged and Extruded Finished Components 36 Cast Shapes 37 Recommended Replacements for Discontinued Alloys 38 Materion Brush Performance Alloys Value-Added Services 39 Custom Fabrication Capabilities 40 Customer Technical Service 40 Other Services 42 Processing and Fabrication Guide 43 Heat Treating Fundamentals 44 Forming of Strip 47 Cleaning and Finishing 50 Joining 51 Machining 53 Hardness 56 Microstructures 57 Other Attributes and Application Engineering Data 59 Fatigue Strength 60 Stress Relaxation Resistance 62 Corrosion Resistance 64 Magnetic Properties 67 Galling Resistance 68 Bearing Properties 69 Friction & Wear Properties 69 Resilience and Toughness 70 Elevated Temperature Properties 71 Cryogenic Properties 72 Other Attributes 72 Your Supplier 73 Company and Corporate History 74 Materion Corporate Profile 75 Brush Performance Alloys Mining & Manufacturing 77 Product Distribution 78 Customer Service 79 Quality 80 Health and Safety, Environment and Recycling 81 Alloy Guide The copper and nickel alloys commonly supplied in wrought product form are highlighted in this section. Wrought products are those in which final shape is achieved by working rather than by casting.
    [Show full text]
  • Substitute Magnetic Materials
    Substitute magnetic materials VED PRAKASH M AGNETIC materials are classified into two main induction behind the magnetising field and can be quanti- groups : soft magnetic materials and permanent tatively judged from the value of coercive force of the magnets. Soft magnetic materials are used on material, the smaller the coercive force the smaller being tonnage scale as cores of transformers and armatures the hysteresis loss. Both the coercive force and the per- of dynamos and motors and principally work in a.c. meability are structure sensitive properties and are circuits. Permanent magnets can deliver a constant influenced by metallurgical factors like interstitial im- amount of energy in it given air gap with or without purities, grain size, lattice imperfection , crystal anisotropy any external aid and are used in a wide variety of electri- mangetostriction . Any treatment or condition, which cal and electronic instruments such as electricity meters, leads to it strain - free lattice and the lowest value of ammeters, voltmeters, loud speakers, telephones. tele- magnetostriction and crystal anisotropy. will lead to the printers, motors, generators, televisions, lifting devices, lowest values of coercive force and highest permeabilities. etc. The manufacture of soft and permanent magnet In short , low coercive force. high permeability, high materials presents a number of problems. They either electrical resistance and excellent rollability are some of contain metals like nickel and cobalt which do not occur the important factors which make a ,citable soft magnetic in India or require high grade starting materials which material . The cost of the melting, rolling and annealing, are not manufactured at present or offer processing to achieve the best magnetic properties may however, difficulties.
    [Show full text]
  • THE EFFECT of INTERLAYERS on Dlsslmllar FRICTION WELD PROPERTIES
    THE EFFECT OF INTERLAYERS ON DlSSlMlLAR FRICTION WELD PROPERTIES Cuauhtemoc Maldonado-Zepeda A thesis subrnitted in conformity with the requirements for the degree of Doctor in Applied Science Graduate Department of Metallurgy & Materials Science University of Toronto O Copyright by Cuauhtemoc Maldonado-Zepeda (2001) National Library Bibliothèque nationale 1*1 of Canada du Canada Acquisitions and Acquisitions et Bibliographic Services services bibliographiques 395 Wellington Street 395. rue Wellington Ottawa ON K1A ON4 Ottawa ON KIA ON4 Canada Canada Your nk, Votm réldrmce Our bire None référence The author has granted a non- L'auteur a accordé une Licence non exclusive licence allowing the exclusive permettant à la National Libraqr of Canada to Bibliothèque nationale du Canada de reproduce, loan, distriiute or sell reproduire, prêter, distribuer ou copies of this thesis in microform, vendre des copies de cette thèse sous paper or electronic formats. la forme de microfiche/film, de reproduction sur papier ou sur format électronique. The author retains ownership of the L'auteur conserve la propriété du copyright in this thesis. Neither the droit d'auteur qui protège cette thèse. thesis nor substantial extracts f?om it Ni la thèse ni des extraits substantiels may be printed or otheTWise de celle-ci ne doivent être imprimés reproduced without the author's ou autrement reproduits sans son permission. autorisation. THE EFFECT OF INTERLAYERS ON DlSSlMlLAR FRICTION WELD PROPERTIES Doctor in Applied Science (2001) Cuauhtemoc Maldonado-Zepeda Graduate Department of Metallurgy & Materials Science University of Toronto ABSTUACT The influence of silver interlayers on the metallurgical and mechanical properties of dissimilar aluminium alloy/stainless steel friction welds are investigated.
    [Show full text]
  • Properties of Some Metals and Alloys
    Properties of Some Metals and Alloys COPPER AND COPPER ALLOYS • WHITE METALS AND ALLOYS • ALUMINUM AND ALLOYS • MAGNESIUM ALLOYS • TITANIUM ALLOYS • RESISTANCE HEATING ALLOYS • MAGNETIC ALLOYS • CON- TROLLED EXPANSION AND CON- STANT — MODULUS ALLOYS • NICKEL AND ALLOYS • MONEL* NICKEL- COPPER ALLOYS • INCOLOY* NICKEL- IRON-CHROMIUM ALLOYS • INCONEL* NICKEL-CHROMIUM-IRON ALLOYS • NIMONIC* NICKEL-CHROMIUM ALLOYS • HASTELLOY* ALLOYS • CHLORIMET* ALLOYS • ILLIUM* ALLOYS • HIGH TEMPERATURE-HIGH STRENGTH ALLOYS • IRON AND STEEL ALLOYS • CAST IRON ALLOYS • WROUGHT STAINLESS STEEL • CAST CORROSION AND HEAT RESISTANT ALLOYS* REFRACTORY METALS AND ALLOYS • PRECIOUS METALS Copyright 1982, The International Nickel Company, Inc. Properties of Some Metals INTRODUCTION The information assembled in this publication has and Alloys been obtained from various sources. The chemical compositions and the mechanical and physical proper- ties are typical for the metals and alloys listed. The sources that have been most helpful are the metal and alloy producers, ALLOY DIGEST, WOLDMAN’S ENGI- NEERING ALLOYS, International Nickel’s publications and UNIFIED NUMBERING SYSTEM for METALS and ALLOYS. These data are presented to facilitate general compari- son and are not intended for specification or design purposes. Variations from these typical values can be expected and will be dependent upon mill practice and material form and size. Strength is generally higher, and ductility correspondingly lower, in the smaller sizes of rods and bars and in cold-drawn wire; the converse is true for the larger sizes. In the case of carbon, alloy and hardenable stainless steels, mechanical proper- ties and hardnesses vary widely with the particular heat treatment used. REFERENCES Many of the alloys listed in this publication are marketed under well-known trademarks of their pro- ducers, and an effort has been made to associate such trademarks with the applicable materials listed herein.
    [Show full text]
  • PRODUCTION of ALUMINIUM BASED COMPOSITES REINFORCED with EMBEDDED Niti by FRICTION STIR WELDING
    PRODUCTION OF ALUMINIUM BASED COMPOSITES REINFORCED WITH EMBEDDED NiTi BY FRICTION STIR WELDING Luís Gonçalves Mendes Dissertação para a obtenção do grau de Mestre em Engenharia Mecânica Orientadora: Professora Doutora Rosa Maria Mendes Miranda, Faculdade de Ciências e Tecnologia Co-orientador: Professor Doutor Telmo Jorge Gomes dos Santos, Faculdade de Ciências e Tecnologia Dezembro de 2012 AGRADECIMENTOS Gostaria de expressar minha gratidão a todos aqueles que, de alguma forma, estiveram envolvidos nesta investigação, sem os quais teria sido impossível apresentar este trabalho. À Professora Rosa Miranda a minha mais profunda gratidão, por me convidar para este desafiador e pioneiro projeto, pelo apoio dado, pelo interesse despertado e tempo investido e pelos conhecimentos transmitidos ao longo deste curso. Ao meu co-orientador o Professor Telmo Santos pelo seu apoio e trabalho em domínios cruciais para o desenvolvimento desta investigação. Ao Professor Pedro Vilaça pelas instalações e suporte técnico durante o trabalho experimental na STM IST. Também, a minha gratidão para com o Professor Pamies Teixeira pelo seu aconselhamento muito bem-vindo. À Professora Raquel Brás pelo seu interesse e apoio, nos ensaios de vibração. Gostaria de agradecer ao Professor Braz Fernandes por todo o seu apoio, tempo investido, interesse e pelo material fornecido. Bem como ao Professor Mahesh e Professor Alexandre Velhinho. À Professora Virgínia Infante pelo apoio técnico e caracterização mecânica realizada no IST. A minha profunda gratidão ao Mestre João Gandra pela total disponibilidade e energia, sem a qual, não teria sido possível realizar este trabalho. Acima de tudo, pelo apoio e amizade. Ao Sr. António Campos e Sr.
    [Show full text]
  • Effect of Some Anions on Corrosion Behaviour of 1060,1100 and 5052 Aluminium Alloys in Orthophosphoric Acid
    Indian Journal of Chemical Technology Vol. 4, March 1997, pp. 101-109 Effect of some anions on corrosion behaviour of 1060,1100 and 5052 aluminium alloys in orthophosphoric acid R S Dubey", R Sagar Dubey, Y D Upadhya &. S N Upadhyay Department of Chemical Engineering and Technology, Institute of Technology, Banaras Hindu University, Varanasi 221 005,'India Received 26 August 1996; accepted 26 November 1996 The effect of chromate, citrate, thiocyanate, tartarate, oxalate and ferrocyanide ions on the corro- sion behaviour of 1060, 1100 and 5052 aluminium alloys in 1% orthophosphoric acid has been studied by weight loss technique at 30 and 40 ± OSC, whereas corrosion behaviour of 1100 aluminium alloy in the presence of above anions was studied by potentiostatic polarisation technique. It was observed that these anions play a decisive role in determining the ease with which the above alloys undergo dissolu- tion in orthophosphoric acid. Chromates, oxalates and ferrocyanides worked as corrosion inhibitors, whereas citrates, tartarates and thiocyanates accelerated the corrosion reaction at all the concentrations (0.01-0.2%) investigated. The stability of the surface film formed in the presence of these anions were closely related to the stability constant of metal-chelate complexes. The presence of anions in aqueous solutions plays of the interesting examples of corrosion inhibitors. an important role in determining the corrosion be- These are ions or molecules with the two or more haviour of aluminium and its alloys. An anion may atoms containing an unshared pair of electrons. act either as a corrosion inhibitor or as an acceler- They donate the lone pair of electrons to the ca- ator.
    [Show full text]
  • Effect of Current Mode on the Plasma Discharge
    Materials and Contact Characterisation IX 3 EFFECT OF CURRENT MODE ON THE PLASMA DISCHARGE, MICROSTRUCTURE AND CORROSION RESISTANCE OF OXIDE COATINGS PRODUCED ON 1100 ALUMINUM ALLOY BY PLASMA ELECTROLYTIC OXIDATION RIYAD O. HUSSEIN1, XUEYUAN NIE2 & DEREK O. NORTHWOOD2 1Natural Sciences Division, Higher Colleges of Technology, United Arab Emirates 2Department of Mechanical, Automotive and Materials Engineering, University of Windsor, Canada ABSTRACT Oxide coatings were produced on an 1100 aluminum alloy using a plasma electrolytic oxidation (PEO) process in an alkali-silicate electrolyte. Three different current modes were investigated, namely DC, unipolar and bipolar. Optical emission spectroscopy (OES) was used to characterize the plasma in terms of the plasma electron concentration and temperature. SEM and EDS were used to characterize the surface morphology and the cross-sectional structure of the coatings. Potentiodynamic polarization corrosion testing was performed in 3.5 wt% NaCl solution for both uncoated and coated samples. Plasma electron temperatures were in the range of 4,500 K to 10,000 K. The plasma characteristics, including sparking, have been related to the surface morphology of the coating. The coating morphology, microstructure and corrosion resistance varied with current mode. A bipolar current mode produced a higher quality (surface morphology, compactness and corrosion resistance) coating than either a DC or unipolar mode. Keywords: PEO coatings, process parameters, plasma characteristics, soft sparking, coating quality, corrosion. 1 INTRODUCTION Aluminum and its alloys are important structural materials in the automotive, aerospace and transportation industries [1], [2]. In order to improve surface properties, such as wear and corrosion resistance, various surface treatments have been employed including electrochemical treatments, chemical treatments and coatings [3], [4].
    [Show full text]
  • Influence of Dislocations on Hydrogen Diffusion and Trapping in an Al-Zn-Mg Aluminium Alloy
    OATAO is an open access repository that collects the work of Toulouse researchers and makes it freely available over the web where possible This is a Publisher’s version published in: http://oatao.univ-toulouse.fr/24132 Official URL: https://doi.org/10.1016/j.matdes.2019.107901 To cite this version: Oger, Loïc and Malard, Benoît and Odemer, Grégory and Peguet, Lionel and Blanc, Christine Influence of dislocations on hydrogen diffusion and trapping in an Al-Zn-Mg aluminium alloy. (2019) Materials & Design, 180. 1-11. ISSN 0264-1275 Any correspondence concerning this service should be sent to the repository administrator: [email protected] Materials and Design 180 (2019) 107901 Contents lists available at ScienceDirect Materials and Design journal homepage: www.elsevier.com/locate/matdes Influence of dislocations on hydrogen diffusion and trapping in an Al-Zn-Mg aluminium alloy L. Oger a,b, B. Malard a, G. Odemer a,L.Peguetb,C.Blanca,⁎ a CIRIMAT, Université de Toulouse, CNRS, INPT-ENSIACET, 4 Allée Emile Monso, BP 44362, 31030 Toulouse Cedex 4, France b Constellium Technology Center, 725 rue Aristide Bergès, CS 10027, 38341 Voreppe cedex, France HIGHLIGHTS GRAPHICAL ABSTRACT • The higher the density of motionless dislocations, the lower the H-induced elongation to failure loss. • H trapping by motionless dislocations limited H diffusion and decreased the H amount at grain boundaries. • H trapping by motionless dislocations promoted a brittle transgranular fracture. article info abstract Article history: Cu-lean Al-Zn-Mg alloys are known to be susceptible to hydrogen embrittlement (HE), which currently limits Received 29 March 2019 their use in automotive industry.
    [Show full text]
  • Optimisation of Process Parameter for Friction Stir Welding of Aluminium Alloy Using Cylindrical Pin Profile
    International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395 -0056 Volume: 04 Issue: 02 | Feb -2017 www.irjet.net p-ISSN: 2395-0072 Optimisation of Process parameter for Friction Stir Welding of Aluminium alloy using cylindrical pin profile Khwaja Muzammil1, Prof. R.D.Shelke2 1 Student,Dept of Mechanical engineering, Everest College of Engineering, Maharashtra, India 2 Professor,Dept of Mechanical engineering, Everest College of Engineering, Maharashtra, India ------------------------------------------------------------------------------***--------------------------------------------------------------------------------- Abstract Objective: Friction Stir Welding is a solid state joining process combining deformation heating and mechanical work to obtain high quality, defect free joints. The objective of the present work is to evaluate the tensile properties of FSW butt joint. In this work, three process parameters such as spindle speed, welding speed and plunge depth were considered for friction stir welding .As it is difficult to perform number of experiments to find out the level combinations which yield good mechanical properties like tensile strength, TaguchiL9 orthogonal array is used to reduce the number of experiment. The material is bought and are cut into specific material and polished. They are then welded based on the different experiment obtained from Taguchi method. After welding is done the metals are cut as per the specific standard. The results are then analyzed using Taguchi method Keywords: Aluminum Alloys, Axial Force, Friction-Stir Welding, Microstructure, Tensile Strength 1. Introduction Friction Stir Welding (FSW) was invented at The Welding Institute (TWI) of the United Kingdom (Cambridge) in 1991 as a solid state joining technique and was initially applied to Aluminum Alloys (Dawes C and Thomas W, TWI Bull, 1995; Thomas W M, etal., 1991).
    [Show full text]