135 research outputs found
Corrosion behaviour of anodised powder metallurgy aluminium-magnesium composites
No full textLink to publisher's homepage at http://www.ttp.net/The corrosion behavior of anodized powder metallurgy Al/2wt%Mg composites reinforced with the short fibre alumina Saffil™ was studied using potentiodynamic polarization in 3. 5% NaCl solutions. The materials under investigation were fabricated using powder metallurgy route. Anodising process has been done to the materials to improve their corrosion resistance. Anodising process were carried out in sulphuric acid solutions with different anodizing voltage, which are fOV, f2V, f4V, f6V and f8V and different concentration of sulphuric acid (5%, %0%, f5%, 20% and 25%). Results from Tafel plot showed that corrosion behavior of PM Al-Mg composites strongly depends on the anodizing parameters. Corrosion resistance increases with the increase in anodizing voltage and concentration of sulphuric acid. The maximum corrosion resistance was recorded by the PM Al-Mg composite anodized using 16V and in the 15% concentration of sulphuric acid
Corrosion behaviour of powder metallurgy aluminium matrix composite reinforced with alumina Saffil™ short fibre
No full textInternational Conference on X-Rays and Related Techniques in Research and Industry (ICXRI 2010) jointly organized by Universiti Malaysia Perlis (UniMAP) and X-Ray Application Malaysia Society (XAPP), 9th - 10th June 2010 at Aseania Resort Langkawi, MalaysiaThe corrosion behaviour of PM Al composite will be affected by the presence of alloying element and reinforcing phase in the composite. This study focused on magnesium and alumina Saffil™ short fibres reinforcement affected to corrosion behaviour of PM AMCs in 3.5wt% NaCl. PM Al composite and PM Al-Mg composite were fabricated from flaky aluminium powder, 2wt% granular magnesium and 15wt% alumina Saffil™ short fibres. The corrosion testing was done using potentiostat Gamry G300 to create Tafel plot and polarization curve. The corrosion effects were analyse using scanning electron microscopy (SEM) and X-ray diffraction analysis (XRD). From experiment, pitting was localized surrounding the magnesium constituents which occur randomly throughout the surface of PM Al-Mg composite. XRD analysis revealed that aluminum oxide (δ-Al Al1.67O4), aluminium hydroxide (Al (OH)3) and aluminium oxide (α-Al2O3) phases were detected in oxide film. The corrosion current density (Icrit) of PM Al composite is lower than PM Al-Mg composite which is 2.0 x 10-1 A/cm2 and 4.0 x10-1 A/cm2, respectively. Magnesium is used as inhibitor in corrosion behaviour of PM Al-Mg composite have been changed and protected with a stable formation of oxide film. The corrosion resistance of PM Al-composite was decreased with the presence of alumina Saffil™ short fibres in composite due to discontinuities in oxide film provided the corrosion initiated in sample
Effect of anodizing parameters on the growth of porous anodic aluminum oxide on al-mn alloys
No full textThe 2nd
International Malaysia-Ireland Joint
Symposium on Engineering, Science and Business 2012 (IMiEJS2012) jointly organized by Universiti Malaysia Perlis and Athlone Institute of Technology in collaboration with The Ministry of Higher Education (MOHE) Malaysia, Education Malaysia and Malaysia Postgraduates Student Association Ireland (MyPSI), 18th - 19th June 2012 at Putra World Trade Center (PWTC), Kuala Lumpur, Malaysia.In this study, the effect of manganese content, anodizing voltage and concentration of
electrolyte on pore nucleation process during anodizing was studied from current density versus time
transient. It was found that the addition of manganese into the aluminum substrate retarded the pore
nucleation process and reduced the steady state current density. Increasing the anodizing voltage
facilitated the pore nucleation and increased the overall current density. However, when the
anodizing voltage is 70V, dielectric breakdown occurred. When the concentration of electrolyte was
increased, no changes to the pore nucleation stage occurred. The overall current density increased
when the concentration of electrolyte increased
Corrosion behavior of Al-Cu-Ni-Y alloys
No full textLink to publisher's homepage at http://www.ttp.net/Al based alloy has been widely used in various industries. This research paper aims at the investigation onto the effect of the percentage of Cu and Ni alloying elements in the corrosion behavior of Al-Cu-Ni alloys. The alloys were characterized by microstructural analysis, physical properties analysis, electrochemical analysis, and phase analysis. By observing the microstructure of the samples, it shows that the dendritic microstructures are occurs. The addition of Ni reveals columnar twinned dendritic to the longitudinal direction of cast ingots. While the addition of Cu increases the density of the sample. The Vickers microhardness test shows that the sample Al86- Ni5-Cu3-Y6 reached the optimum of the hardness value which is 51.36 HV. Tafel Plot that performed shows that Al86-Ni5-Cu3-Y6 has the highest Polarization Resistance, Rp, 2 031.82 kΩ and lowest corrosion rate, 0.00380 mm per year. An alloy with high Rp value is highly resistant to corrosion
A study on the effect of modified electrolyte to the formation of AAO membrane in anodising process
No full textLink to publisher's homepage at http://www.scientific.net/The formation of anodic aluminium oxide (AAO) membrane in anodising process has been studied. The anodising process was done in two different type of electrolyte which are single phosphoric acid and a mixture of phosphoric acid and acetic acid. This study was done to determine the influence of this mixed electrolyte toward the formation of AAO membrane. The anodising voltage was control from 90V to 130V while concentration, time, and temperature were kept constant at 1M, 60 minute and 15°C respectively. The characterisation of the AAO membrane was done by using scanning electron microscopy (SEM). The results of this study confirm that the addition of organic acid in the acidic based electrolyte resulted to the larger pores size of AAO membrane
Electrochemical characterisation of hybrid activators for aluminium sacrificial anodes in natural sea water
No full textLink to publisher's homepage at http://mycc.my/This paper reports on the electrochemical behaviour of as-cast Al-Zn-Mg alloys activated by tin (Sn) and ruthenium dioxide (RuO2) in natural sea water. The potential and advantages of Sn and RuO2 as hybrid activators in Al-Zn-Mg alloys will be studied by using direct (DC) and alternating (AC) current electrochemical measurement techniques. The morphology of the alloys' corroded surface was studied using a scanning electron microscope (SEM). This study showed that the addition of 1.5%wt. Sn as an alloying element gave a stable corrosion free process that can be achieved after 2 ks of immersion. The results also showed that RuO2 catalytic coating applied on the surface of Al-Zn-Mg-Sn alloy slightly shifted the values of open circuit potential (OCP) towards a more electropositive direction as compared to Al-Zn-Mg-Sn without RuO2. The morphology of the corroded surface of Al-Zn-Mg-Sn alloy coated with RuO2 showed a more uniform corrosion attack with the formation of porous and fibrous mud-like cracks on the outer layer. This type of corrosion morphology features were believed to facilitate ionic species adsorption and diffusion through corrosion product layer at solution-alloy interface. Electrochemical impedance spectroscopy (EIS) showed that both Sn and RuO2 are capable to activate Al-Zn-Mg-Sn alloy in sea water by modifying the electrical properties of the oxide layer, reducing resistance to polarisation Rp values and thus, activating and accelerating the aluminium alloy dissolution process
AMCSKUK®: Aluminium Matrix Composite from AL SCRAP and Short Fibre-Alumina
No full textEkspo ini berlangsung di Dewan Sek. Men. Putra, Kangar, Perlis.Application of the AMCSKUK using in small automotive component like screw washer, bolt, and nut. Can be used to replace current product made by particle reinforced metal matrix composit
Study of erosion corrosion in oil and gas industry
No full textThis project is about study of the erosion corrosion in oil and gas industries based
on the samples from Petronas Gas Processing Plant. The microstructure and hardness analysis was done to the sample ASTM A 105 Carbon Steel (elbow that failed due to erosion corrosion). Found that the microstructure and hardness of failed samples was altered and different compared to new sample (with same grade of carbon steel). Experiment on erosion corrosion was design in order to get more understanding on erosion corrosion mechanism. Result of experiment shown weight loss of the sample is 6 grams for 37 hours experiment. In order to measured corrosion rate of the sample, tafel plot (electrochemical techniques of corrosion measurement) was run by using Gamry
Instruments. From data gathered, the corrosion rate of ASTM A 105 carbon steel in Sodium Chloride environment is 3.070682E-03 millimeter per year (mm/year)
Titled optimisation of anodising parameter with oxalic acid for the formation of anodic aluminium oxide
No full textAccess is limited to UniMAP community.This thesis discussed on the optimisation of anodizing parameter with oxalic
acid for the formation of anodic aluminium oxide (AAO) by using Taguchi Methods.
During one-step of anodization technique is performed, porous of AAO has been
formed at the surface layer in the presence of oxalic acid. Since the pH value of oxalic
acid is below than 5, it is suitable to produce nanoporous oxide layer. Regularity is
defined as the structure with small or large size in pore formation, distance between
each pore and the arrangement of AAO formed. The challenges in growing AAO are
such as to get the specific size as we targeted to have and the regularity of the pores.
Based on the literature review, four main anodizing parameters which are electrolyte
temperature, electrolyte concentration, voltage and time should be well control so that
the pore size and regularity can be control. In order to study the formation of AAO at
the minimum size of pores and better regularity, anodizing parameter is optimized by
L9 Taguchi Orthogonal Array. Scanning Electron Microscope (SEM) is used to
observe the regularity of the pores and to measuring the pores size while X-Ray
diffraction (XRD) is used to study the crystallinity structure of AAO. From the result,
20℃, 0.3M, 40V and 30 minutes are selected as the most optimum combination of
anodizing parameter in order to study the pore size while 20℃, 0.4M, 25V and 30
minutes are selected as the most optimum parameter for regularity of AAO. The
percentage influence of each main factor for pore size is also calculated to be 67% for
electrolyte temperature and the rest which are electrolyte concentration, voltage and
time give the same percentage (11%). Meanwhile, the percentage influence for
regularity aspect are 39%, 37% 19% and 5% for voltage, electrolyte temperature,
electrolyte concentration and time respectively. X-Ray Diffraction (XRD) analysis
proved that aluminium oxide is presence after being anodized
Conductive coating strategy for Magnesium alloy as a surface protection and reliability
No full textThe methods and technologies in various coatings for magnesium alloys are studied. The magnesium alloy used in this final year project is AZ91D, which is still in very early using stages in semiconductor industry. This final year project is carried out to study on AZ91D applications and properties, especially the corrosion resistance of AZ91D. One of the most commercial solutions to prevent corrosion of AZ91D is by coated the material with a protective layer, which is called coating. Without proper coating, AZ91D is not adequate for use in harsh service conditions, as they are intrinsically highly reactive and usually have relatively poor corrosion resistance, which restricts the application of AZ91D in practical environments. Besides of corrosion resistance, coatings are also important in soldering, cosmetic, shielding, hardness and
so on. There are four coating methods studied in these final year project, which are electroless nickel plating, zirconium plating, shadan passivation and spray painting. Those coatings have different function and usage, thus several testing involve surface protection and reliability
properties is done to investigate, compare and determine type of coating which is the most suitable and feasible to be used. The testing involved are salt spray test, humidity test, temperature shock resistance test, dry tape adhesion test, Vickers hardness test, Norman abrasion resistance test and cross sectioning. From result obtained, spray painting have greater corrosion resistance than other coating designated for this project, but very poor reliability when subjected to sudden temperature change. Electroless nickel plating with thickest coating layer is able to provide appropriate hardness and unquestionable abrasion resistance far better than other coating sample
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