Materials Science and Engineering Commons^™

Intergranular And Pitting Corrosion Mechanisms Of Sensitized Aluminum Alloy Aa5083, Clayton Egleston

Williams Honors College, Honors Research Projects

The motivation and objectives of this project is to examine the mechanisms of intergranular corrosion (IGC) and pitting corrosion of sensitized AA5083. In this regard, different characterization techniques were used, including optical analysis of microstructure, cyclic potentiodynamic polarization with Tafel fitting, electrochemical impedance spectroscopy with electrical equivalent circuit (EEC) fitting, and potentiostatic current transient monitoring. The transition from IGC to pitting corrosion occurs when the grain boundaries become saturated with the β-phase (Mg₂Al₃). It was found that AA5083 becomes more vulnerable to pitting corrosion as the degree of sensitization increases.

Non-Destructive Material Analysis Of Metals And Composites Via Thermography, Jonathan R. Doubt, James L. Chapman

Materials Engineering

The Naval Surface Warfare Center, Port Hueneme Division, is interested in the development of non-destructive damage assessment of shipboard materials via drones at distance. Long Pulsed Thermography (LPT), a method of non-destructive evaluation, was investigated as a possible method for detecting damage in metals (5005h24 Al alloy and 1008 carbon steel) and composites (aramid fiber honeycomb sandwich structure) at distances from 0.5 m to 3.0 m. LPT was conducted using two 1000 W can lights to heat the samples, and a FLIR E8-XT thermal camera. The images were then analyzed using ImageJ software to determine if damage could be detected …

Atmospheric Corrosion Of Galvanically Coupled Aluminum Alloys And Carbon Steel, Mitchell Felde

Williams Honors College, Honors Research Projects

Aluminum alloys are a steadily growing material being commonly used in lieu of typical steels. Additional alloying, heat treatment, and other property enhancing processes are expanding the use of these alloys. However, with this expansion, galvanic corrosion is becoming more of an issue in the design stage due to the combination of these alloys with steels. The automotive industry is one industry where the use of aluminum alloys is becoming common practice. Aluminum alloys provide a lightweight aspect over the conventional carbon steel that was used previously. As a result of this transition towards more lightweight materials, galvanic coupling is …

Benefits Of Aluminum: Comparing The Common Materials In The Bar Grating Industry, Joanthan Geiser

Williams Honors College, Honors Research Projects

The main aim of this project is to study the wholistic behavior of the 6xxx series of aluminum for use in the bar grating industry for a waste water treatment environment. This project will study the comparison of certain aluminum 6xxx series alloys to steel, stainless steel, and glass fiber-reinforced plastic. While comparing these materials, it will look at the mechanical properties such as modulus of elasticity, yield strength, and ultimate tensile strength. In addition, the available corrosion test of the 6xxx series aluminum alloys will be examined to find a generalization of the corrosion behavior for this series. A …

The Effects Of Carboxylic Acids In Aluminum Anodizing, Abby E. Koczera

Honors Theses and Capstones

Hard-anodized alumina coatings were formed in sulfuric acid at low temperature and high current density in the presence of carboxylic acid additives. Citric acid, trimesic acid, mellitic acid and ethylenediaminetetraacetic acid (EDTA) were utilized in varying concentrations. The additives were chosen for their capacity to form complexes with tri-valent aluminum and hence impart chemical stability to the coatings. The coatings were sealed in boiling water, and corrosion resistance was observed in a high pH solution of potassium hydroxide. The coatings were examined using scanning electron microscopy (SEM) to assess coating thickness and pore dimensions. Thicker coatings were produced when the …

Investigation Of Outlife Time On The Environmental Durability Of P2-Etched, Adhesively-Bonded Aluminum Alloys Using The Astm Wedge Test, Daniel Gross, Corey Sutton

Materials Engineering

P2 etchant is an environmentally-friendly aluminum etchant which has the potential to replace the Forest Products Laboratory (FPL) etchant as the industry standard. Environmental durability of adhesively-bonded aluminum surfaces etched using a paste version of the P2 etchant were tested using the Boeing-developed wedge test (ASTM D3762 - 03(2010)). This project specifically aimed to examine the relationship between outlife time (the time between etching and adhering) and the ability of bonded aluminum samples to pass the wedge test. Two aluminum alloys, 2024-T3 and 7075-T6, were wedge tested and the etched surfaces examined with an atomic force microscope (AFM) and a …

Surface Modification Of Aluminum Alloys By Plasma Electrolytic Oxidation, Vahid Dehnavi

Electronic Thesis and Dissertation Repository

Plasma Electrolytic Oxidation (PEO) is a surface treatment for the production of ceramic oxide coatings with great properties, such as high wear and corrosion resistance, on metal substrates, particularly aluminum and magnesium alloys. Formation of PEO coatings involves complex processes and mechanisms that are difficult to study. Currently, the PEO process is in a transition phase from research to commercial application, with a primary focus on the corrosion and wear protection of light alloys, and has recently generated interest as a promising surface treatment for biomedical applications.

To justify the industrial application of PEO, a more systematic and in-depth study …

An Exploratory Investigation Into How Cold Working Can Affect The Acoustic Performance Of Thin Aluminum Foil In A Ribbon Microphone, Alexander (Alex) Stanley

Materials Engineering

Ribbons of 4 μm thin 99.1% pure aluminum foil were cut and corrugated to replace the stock ribbon in an Apex 205 ribbon microphone. Prior to corrugation, half of the ribbons were sandwiched between two KimWipes and two pieces of cardstock then hammered to impart strain hardening. Each ribbon was placed into the microphone capsule and the frequency response of each ribbon was measured. A 10 second sine sweep from 20-20,000 Hz was played through a KRK Rokit 5 speaker and recorded through a ribbon microphone placed 6 inches away from the speaker cone. The signal generated by the ribbon …

Characterization Of Aluminum-Boron Carbide Particulate Metal Matrix Composites, Eric Blank

Materials Engineering

The analysis of die-cast 380 aluminum-boron carbide particulate metal matrix composites (MMC) was performed in order to see if the samples had the required tensile strength of 300 MPa. 10wt% B4C die-cast samples were produced and tested. Half were heat treated to the T6 condition and the others were left as cast. Using ASTM standard B 557M it was found that the average tensile strength for the as-cast samples was 130 MPa and the heat treated samples had a tensile strength of 93 MPa. These values were both lower than expected. The heat treated samples were not expected to have …

Cracking In Cycloaliphatic Epoxy/Aluminum Composite Electrical Bushings, Keith Alan Parker

Doctoral Dissertations

The problem of cracking in electrical apparatus bushings as a result of thermal stresses was investigated. The bushings were composed of cycloaliphatic epoxy insulators with embedded aluminum conductors. The problem is due to the difference in coefficients of thermal expansion of the two materials. A solution to the problem had been to coat the conductors before they were formed together with the epoxy insulators. The coating was assumed to prevent cracking by allowing movement between the two materials as their dimensions changed during thermal expansion and contraction. The contribution of the coating was to be established.

The hypothesis was that …

The Construction And Operation Of A Universal Specimen Mount With Protective Lead Shield For The Purpose Of Determining Pole Figures Using The Schulz-Decker Transmission Technique, Richard L. Fausner

Bachelors Theses and Reports, 1928 - 1970

It was the purpose of this study to construct a universal mount, to construct a protective lead shield, to operate the instrument, and to provide a pole figure using the transmission method of Schulz and Decker. There are at present several lengthy x-ray methods of determining the grain orientation of metals. These methods are mainly photographic. In order to provide a rapid means of obtaining the necessary information concerning the grain orientation of a metal, a universal mount was constructed.

The Effect Of Germanium On The Current Efficiency In The Electrolysis Of Pure Zinc Sulfate Solution, Keith R. Bock

Bachelors Theses and Reports, 1928 - 1970

It has long been recognized that electrolytic zinc cells are extremely sensitive to impurities. In fact, cer­tain impurities present in amounts as low as 0.1 mg/1 cause a serious loss of current efficiency. Also, the presence of several impurities in the electrolyte may accelerate the detrimental effect of each impurity.

Recrystallization Of High Purity Aluminum, Virgil H. Griswold Jr.

Bachelors Theses and Reports, 1928 - 1970

If a metal is first cold-worked and then heated to a sufficient temperature for an adequate length of time, the hardening properties due to cold-working disappear, and the metal will return more or less to its original state. Upon examination of the microstructure, we find that new grains have replaced the old grains through what is called recrystallization. The final size of the recrystallized grains depends upon three important variables--the degree of cold-work or deforma­tion, annealing temperature, and annealing time.

The Effect Of Manganese On The Age Hardening Of Aluminum-Copper Alloys, Keith P. Burgess

Bachelors Theses and Reports, 1928 - 1970

It is known that age-hardening occurs in alloys of the solid solution type containing a hardening constituent, of a metal or metallic compound which is more soluble in the solvent phase at higher tempertures than at lower temperatures.

The Metallography Of Aluminum Casting Alloys, Donald D. Goehler

Bachelors Theses and Reports, 1928 - 1970

The purpose of this thesis is to supply the Montana School of Mines with an up to date source of information concerning the metallography of aluminum casting alloys. This thesis is designed as a continuing project. Ultimately, it is hoped that a catalog containing all the typical structures of aluminum casting alloys will develop.

The Age-Hardening Of Aluminum With Mgzn2, Sidney E. Worthen

Bachelors Theses and Reports, 1928 - 1970

The purpose of this thesis is to investigate the age-hardening of aluminum with magnesium and zinc in such proportions as to conform to the compound MgZn₂.

Because of a lack of time and proper equipment, the only property investigated was the hardness as indicated by the Rockwell Superficial Hardness Tester.

The Age Hardening Of Silver With Copper-Silicide, Joseph Edward Shaw

Bachelors Theses and Reports, 1928 - 1970

The successful application of the phenomenon of pre­cipitation hardening to aluminum and copper has indicated the possibility of hardening all metals in the same way. The phenomenon of age hardening was discoveredin 1911, and since that time much research has been car­ried on in all parts of the world on various alloy sys­tems.

Structure Of Eutectics, Dilip K. Das

Bachelors Theses and Reports, 1928 - 1970

The present paper is a result of work done on the study of structures of eutectics of a certain eutectic-forming binary systems. In this research work no systems with intermetallic compounds have been studied.

The Electroplating Of Cadmium From Sulfate Solutions, Lewis S. Prater

Bachelors Theses and Reports, 1928 - 1970

It has been proven that cadmium forms a very satisfactory plate on steel, which has to withstand severe corrosion, especially the corrosion of sea water and spray. The metal is now successfully plated electrolytically from cyanide solutions, but wherever work is carried on with cyanide, there is great danger of poisoning to the workers.

The Electrolytic Deposition Of Chromium Upon Aluminum, E. Fults, L. D. Voerge

Bachelors Theses and Reports, 1928 - 1970

The purpose or this investigation is primarily to determine the best conditions for plating chromium on aluminum. The work was carried out with the hope of obtaining coherent deposits, and of determin­ing the conditions under which such deposits may be duplicated.