The Aluminum processing industry benefits greatly after Aluminum anodizing is done. Fundamentally, this reinforces, beautifies and increases its corrosion resistance. This guide here attempts to explain the basic methodologies, techniques, and steps concerning the anodizing procedures. This document serves as a full primer and aimed toward the general public who wishes to grasp the concepts behind anodized aluminum, including design engineers, engineering technologists, and practitioners. As explained earlier, anodizing adopts various processes – understanding the benefits and shortcomings of these will aid readers in grappling with the intricacies of the interface of technical and practical complexities of anodizing. That is why we have crafted this guide in a manner ensuring readers reach the peak of excellence on the topic.
What Is The Anodizing Process of Aluminum Parts?
Anodizing is a process that enhances the existing oxide layer on aluminum parts to improve mechanical properties, aesthetically promote the item, corrosion resistance, and growth of the artificial oxide layer. To perform this process, aluminum parts must be submerged into an electrolytic solution, which, is usually sulfuric acid, and an electric current must pass through it. Exothermically, the process grows an oxide layer on the surface of the aluminum part in which the part can later be dyed or sealed to obtain further value. Other types of anodizing includes Type I (Chromic acid), Type II (sulfuric acid), and Type III (hard anodizing) and all differing in the thickness and attributes to best suit diverse applications.
The aerospace, electronics, and automotive industries extensively use anodizing because of features such as light weight, non conductivity, abrassion resistance surfaces, and the alteration resistant surfaces finishes it renders.
Understanding Anodized Aluminum
The A-sided LTD sheet offer easy permanent marking and a range of capabilities making it suitable for various unique requirements of each client. They also increase the exterior durability of the item, making it resistant to scratches, splits, and rips.
The advanced anodized layer functions as a shield enveloping the aluminum underneath, providing protection from moisture and chemical exposure, likewise applying to Type II anodized shields possessing a thickness of 0.0002 inch to 0.001 inch.
This allows for a higher level of corrosion and oxidation resistance in robust industrial and marine environments.
Type III hard anodizing (over 0.001 inches) or deep hard anodizing provides extreme surface abrasion resistance, exceeding 60 Rockwell C, ideal for aerospace parts and high-wear machinery components. The coating can endure massive thicknesses ranging from 0.001 to 0.004 inches.
Anodizing in itself does not require any form of insulation for electrical isolation where isolation grade is mandated, meaning it is useful for critical electric components that require such features.
Having the anodizing process done with the addition of pores means the anodized aluminum can endlessly be dyed in endless combinations of colors while upholding UV stability. This makes the finish highly resistant to fading and degradation from sunlight.
Anodizing produces a small amount of waste compared to other processes. Unlike other coating techniques, it does not release any VOCs. With aluminum being one of the most easily recyclable metals, the process is more eco-friendly and sustainable.
Anodized aluminum stands out as a primary material in industries that require extensive customization due to the advanced range of techniques and dyes available for anodizing.
Role of An Electrolyte in the Anodizing Process
Anodizing cannot proceed without the presence of an electrolyte: they are needed for the chemical reaction involved in the modification of the oxide layer on the aluminum surface. Generally, anodizing is best performed in sulfuric acid because it yields dense and uniform oxide layers with it’s anodizing electrolytes. Phosphoric acid, chromic acid and even some organic acids can be used as well depending on the desired result.
General purpose anodizing:
Sulfuric acid: 10-20% by weight.
Chromic acid: ~3-10% by weight: Corrosion resistant anodizing for aerospace applications
Phosphoric acid: 15-25% by weight: Used for bonding in adhesion promotion.
Also some organic acids like oxalic acids serve other specific aesthetic purposes.
The properties of each anodized layer vary with changes in electrolyte concentration. Other equally important parameters like temperature, current density, and pH level also need to be controlled in order to achieve optimum coating thickness and porosity in the anodized coating. Take for instance the case of sulfuric acid, which can be performed within the range of 12-24 A/ft² (1.3-2.6 A/dm²) current densities at 20-22°C (68-72°F). Any changes in these parameters would lead to a compromise on the coating’s endurance and aesthetic appeal.
Significance of Oxide Layer Development Alike II
An anodizing operation has a critical step which is the development and growth of an oxide layer by controlled electrochemical oxidation of aluminum surface. The rate of this elementary anodic reaction is controlled by the specific anodizing procedure implemented. For example:
In Type II Sulfuric Acid Anodizing the oxide layer is moderately decorative and protective, reserved at a thickness between 0.0002 to 0.001 inches (5 to 25 microns).
In Type Hard Coat Anodizing III, the oxide layer at times can be produced to a thickness of 0.001 to 0.004 inches (25 to 100 microns), significantly improving wear and corrosion resistance for use in aerospace and industrial machinery.
The change in composition of the electrolyte, voltages, treatment temperature, and time of treatment can create distinct changes in the pore size and the porosity of the oxide layer. For many changes these parameters need to be controlled to achieve optimal precision. For those decorative applications where close dye absorption is allowable, the dye pores should be capped in order to achieve the best anti-corrosive efficacy, so control over these parameters is important.
How Does Anodizing Aluminum Enhance Corrosion Resistance?
Why Understanding Corrosion Resistance is Important
By applying anodizing, the corrosion resistance of aluminum is improved due to the addition of an anodic oxide layer of aluminum oxide. Anodization processes change existing aluminum oxide into thicker, more effective layers as it uses the electrolytically formed oxide aluminum coating. This coating is far more resistant to moisture, chemicals, and UV radiation than it is to corrosion. Furthermore, other methods of sealing the pores of the oxide layers with additional protective coatings improve oxidation and degradation and ensure reliability in extreme environments. These methods are used in aerospace, automobile, and construction industries as they enhance the reliability and strength of aluminum parts.
How Thin Protective Oxide Films are Produced/ Formed
Anodization is one of the techniques used for aluminum finishing and this is how an aluminum protective oxide layer is formed. In anodization, aluminum is typically oxidized in an electrolytic solution, frequently sulfuric acid, to create an aluminum oxide layer. Depending on the treatment and application requirements , this layer usually attains a thickness somewhere between 5 and 25 micrometers(μm).
Research indicates that the corrosion resistance of aluminum can increase up to 500% with the application of anodized oxide layer in comparison to non anodized aluminum.
Moreover, the surface of anodized aluminum tend to lie between 200 to 400 HV (Vickers Hardness) as opposed to 20-50 HV for non-anodized aluminum. Due to these properties, anodized aluminum has shown to withstand harsh environments subjected to strong abrasive forces and corrosive solvents.
Furthermore, the pore sizes within the oxide layer are usually between 10 to 100 nm (nanometers) allowing specific modification of dyes or seals. The ability to seal the pores with siloxane has demonstrated to diminish the surface permeability by as much as 98%, thereby enhancing resistance to oxidation and wear.
Comparison of Anodizing with Other Metal Treatments
Anodizing: The level of surface hardness achieved is up to 9 Mohs, which is roughly equal to that of a sapphire.
Electroplating: Softer and more scratch prone coatings are added.
Impact can cause chipping but otherwise very durable, that is the nature of Powder Coating.
Anodizing: Sanding and buffing, when used on treated sealed pores, increase resistance to almost 98%.
For Electroplating: Moderate protection is possible with some dependance on the metal in use like a zinc plated sacrificial protection.
Establishing a confining layer is one thing, forming it in surrounding out to be hostile like in case of Powder Coating is a challenge.
Dyes can be applied without fading and numerous color is possible as the metal layer retains the dye in case of anodizing.
Electroplating: Achieving polished and metallic finish but few colors available.
Desirably subdued and gleeming hues avalilable in Powder Coating, but numerous colors leads to exposure to UV rays fading the powder.
Anodizing: For standard applications the range is from 5 to 25 microns, hard anodizing processes can achieve up to 100 microns.
Electroplating: Coating thickness is usually from 2 to 10 microns.
Powder Coating has a thickness range of 50 to 300 microns.
Anodizing: Capable of sustaining robust thermal stability while withstanding temperatures over 1,200°F (650°C).
Electroplating: Tends to perform poorly at most extreme temperatures but has some level of performance with varying layers.
Powder Coating: Suffers above 300°F (150°C) but is relatively effective below that threshold.
Anodizing: Alternative anodizing methods can achieve lower cost, but only if high performance criteria are met while preserving enduring value.
Electroplating: Carries relatively low-cost decorative scope, but overall can increase expenses aimed at protecting from corrosion.
Powder Coating: Reasonably priced for low-detail bulk work that requires minimal detail.
The conclusion of this analysis makes it clear that the most effective treatment in terms of durability, corrosion resistance, and customizability is anodizing due to its unrivaled adaptability, while alternative methods offer lower cost efficiency without sacrificing performance.
What are the Different Types of Anodizing?
Exploring Type II Anodizing
Anodizing comes with its special preferences, and we may say type II is the one most used: This is the case with anodizing type II or also known as sulfuric acid anodizing. The reason for this is its unrivaled cost effectiveness as well as multifunctional traits. In this method, aluminum is immersed in a sulfuric acid electrolyte solution, and the current is passed through the bath. The resulting layer is begotten in the form of an acid resistant layer which has thickness between 0.5 to 1.0 mils or 12 to 25 microns.
As it is evident, some of the most important defining features of Type II anodizing are moderate resistance to corrosion, good wear resistance and great dye absorption which makes it widely usable for both functional and decorative purposes. We can also notice that finishes of Type II anodized are extensively used in consumer electronics, the automotive industry and architecture.
Corrosion Resistance: Endurance of up to 336 hours of salt spray testing depending on seal used during treatment.
Hardness: The concentration of the salts that create the oxide layer imparts hardness of 200-400 HV Vickers Hardness.
Thickness Tolerance: Control better than ±10% given on anode thickness.
More supportive colors relative to other dyes are available for selection because the absorption capacity of anodized layer dyes is much higher.
This process stands out from the rest when considering a blend of aesthetics, cost-effectiveness, and durability, making it suitable for modern complex tasks.
Additional Characteristics of Type III Anodizing
Demand for endurance and duraibilty is high in aerospace, automotive, and military which is why Type III anodizing is so common. Applications include aircraft components and firearm parts as well as tools where great corrosion resistance provided by hard anodizing is crucial. It is frequently employed in parts exposed to extreme friction or harsh environments due to the protective coating it offers.
Futhermore, Type III anodizing is prefered over the other types so coat hardness is the main consideration.
Disadvantages of Hardcoat Anodizing
Hardcoat anodizing or Type III anodizing has numerous advantages detrimental for applications of high performance:
The layer of anodized attained with Type III, also known as hard anodizing, is usually around 60-70 HRC and 400-600 HV. This level of hardness, even under severe wearing of high friction or continuous movement, ensures superb wearing resistance.
The over 336 hours of resistance to corrosion in salt spray testing (ASTM B117) proves that hardcoat anodized materials are dependable. However, they are only dependable in the absence of moisture, salt or other corrosive agents.
Flexible adaptation comes from being able to increase the conditions of application, but the standard range of coating thickness for hardcoat anodizing is 0.001-0.003 in (25-75 microns).
Insulation for thermal and dielectric strength applications is needed, which builds up to 2000 volts per 0.001 inch burst, displaying the thermal and electrical stress shielding capability of the elements requiring insulation.
While Type III anodized parts are usually light or dark in color, they can be accessorized with some colors. Since the additional colors do not affect the mechanical performance of the parts, this gives more options for customization.
The accuracy in operation and lifecycle of the components is masked by the make them the most popular choice for surface treatment in the industries which need these features.
How is Dye Used in the Anodizing Process?
Color Anodizing Technique
The anodizing dyeing process is the coloring of the porous oxide layer that forms on the surface of the metallurgical parts, mainly Aluminium, and as such, achieves its metallurgical working. Almost always, anodizing dyeing is done after an anodizing layer with a uniform and stable oxide was formed on the surface of the material, by immersion in a dye bath, which is a more porous structure. It is well known that there are many types of dyes available, organic and inorganic, for this purpose which can enhance customization.
The dyeing of anodized parts is followed by a sealing step which enhances and stabilizes the durability of the color. This step also increases the wear, UV radiation, and environmental damage that the part is exposed to. The dye is kept stranded in the oxide layer by pores which are sealed. Type III (hardcoat) anodized parts are less vibrant because of the deposition of a dense layer of oxide. However, suitably applied dyes can be used to make those parts retain strength while ahcieving vibrant colors. This is often seen in parts which are used in aerospace, automotive, and consumer goods where strength and improved aesthetics are required.
Choosing the Right Dye For Your Job
While choosing a dye for your anodizing task, do consider the following:
Application Needs – Determine if the part is merely decorative or has some structural function. This will impact the selection of the color and the dye’s durability.
Lightfastness – For components that will be exposed to the sun and other harsh conditions, use dyes that are not easily damaged by UV light.
Chemical Compatibility – Ensure that the selected dye is compatible with the anodizing process and operational conditions like extreme heat or cold weather and chemical exposure.
Desired Apperance – Ensure the selected dye will meet the specified color requirements and finish, whether glossy, matte, or metallic.
Industry Standards – Check if the dye has some predetermined requirements pertaining to your project or industry such as certain performance specifications or MIL-SPEC standards.
These recommendations enable one to make the most economically advantageous and optimal decisions for the details of an anodizing application.
Consequences of Dye on Anodized Finish
The choices of dye directly coincide with the impact properties and performance of the anodized finish. Below are arguments with data.
There are differences in resistance to UV radiation and other environmental stresses for anodizing dyes. For instance, laboratory studies indicate that organic dyes have the potential to diminish in color by approximately twenty five percent after five hundred hours of UV exposure while inorganic pigments lose less than five percent in the same period.
The application of certain dyes has been proven to enhance the corrosion resistance of the anodized layer better than other dyes. Research shows that the use of performance dyes containing nanoparticles in salt spray environments increases the coating’s resistance by thirty percent when compared to standard dyes.
Thermal stability of anodized finishes is retained under high temperature throughout the range until caled grade 3 ewe x dye is applied. Low grade dyes have shown structural and color permanence at elevated temperatures around 200 degrees centigrade, whereas standard dyes fail at approximately 150 degrees celsius.
Why is Sealing Important After Anodizing Aluminum?
The Role of Sealing in Anodizing
While anodizing increases the performance attributes of aluminum oxid and improves its hardness and wear-resistance, sealing is undoubtedly one of the most important processes that further increases the anodized layer’s functionality and durability. If the aluminum oxide layer is not sealed after anodizing, its porous structure is prone to capture particulate contaminants and can be attacked by corrosion, leading to premature failure. The purpose of sealing is to block pores, which prevents leakage from within the material, thus producing a more durable and stable coating. This is a critical requirement in order to enhance the corrosion resistance of the material and protect it over a long period of time, particularly in hostile environments. Furthermore, sealing assists in anchoring the dyes when colored anodizing is performed so that coloring does not fade or degrade over time. Typical methods of this are hot water sealing where the oxide layer is hydrated or cold sealing where chemicals are used to rapidly achieve a seal.
Methods and Materials for Good Sealing Practices
Sealing with hot water is popular because of its effectiveness. This technique requires dipping the anodized aluminum into deionized water whose temperature is usually maintained between 180°F-212°F (82°C-100°C). This process aids in the hydration of aluminum oxide layer forming a more stable boehmite which plug the pores. Research indicates that the sealing period for optimum corrosion resistance is between 15 and 30 minutes depending on the thickness of the anodized coat. This technique is useful in applications that require very high strength because optimum results can be achieved with very few chemical treatment.
As for cold sealing, it relies on chemical agents such as nickel fluoride or cobalt sealants to effect pore closure at lower temperatures 70°F to 90°F (21°C to 32°C). This method uses less energy and is quicker, requiring only 2 to 10 minutes of treatment. Data suggests under certain conditions, processes utilizing cold sealing accomplishes the same level of corrosion resistance as hot water sealing. However, cold sealing tends to be less reliable for severe environmental impacts and is typically applied where quick and economical measures are favored.
Data from the comparison of hot water sealing to cold sealing suggest that the former has a slight edge on sustained exposure to chloride pitting corrosion, as samples with hot water sealing showed increased corrosion potential (Ecorr) of around 20% compared to cold sealing. Furthermore, evaluations on retention of color indicate that hot water sealing performs better by up to 10% in stability of dye against UV exposure when compared to accelerated testing, making it more effective for applications where enduring brilliance is needed.
How Sealing Enhances Adhesion and Wear Resistance
Figures below show the performance differences from controlled experiments with hot water versus cold sealing.
- Hot Water Sealing: Achieved an Ecorr improvement of approximately 20%, indicating superior long term resistance to chloride induced pitting corrosion.
- Cold Sealing: Lower Ecorr improvement compared to hot water sealing; clearly less effective in harsh environments.
- Hot Water Sealing: Showed up to 10% better dye retention in accelerated UV exposure tests, critical for maintaining color vibrancy outdoors.
- Cold Sealing: Experienced significant fading over time under UV exposure compared to Haw Water.
- Hot Water Sealing: Increased adhesion strength by approximately 15% compared to unsealed or cold sealed samples.
- Cold Sealing: Clear increases in adhesion strength but less suitable for applications requiring strong bonding.
- Hot Water Sealing: Improved surface wear resistance due to denser crystalline sealing layer formation.
- Cold Sealing: Moderate wear resistance but less durable compared to hot water processing.
- Hot Water Sealing: Requires longer processing times, generally ~20-30 minutes depending on the substrate and desired properties.
- Cold Sealing: Typically done in 5 to 10 minutes, making it appropriate for high-volume production lines, because of faster processing time.
The information outlines the two techniques’ advantages and disadvantages, where hot water sealing is optimal in durability and performance, while cold sealing is more appropriate for speed and cost-effectiveness.
What are the Applications of Anodized Aluminum Parts in Industry?
Applications of Anodized Coating in Aerospace
Due to the anodized aluminum coatings ‘s extreme strength, the aerospace industry uses them. The anodized layer Otypically shields the base metal from moisture and oxygen, which are critical factors in abrasion resistant surfaces. protective components in the aerospace industry.
As with odher alloy constituents and process parameters, anodizing results in anodized coatings hardness value of Vickers 200 to 600 HV. This provides some amount of surface mechanical wear and sustained damage.
Anodized aluminum exhibits corrosion from fog, salt and humid environment with satisfactory degradation. It meets the requirements of basic MIL-A-8625, Type II or Type III. Salt spray tests frequently show more than unsheathed 200-500 hours.
The pore structure of anodized layers ensures proper interfacial adhesion for splash paints, primers, and therefore, greater strength in worn coated structures. These attributes increase the robust and construction of aircraft fuselage, the limbs structural wings and parts where lightweight airplane features withstand harsh environmental weather extremes such as severe changes.
Application of Anodized Aluminum in Consumer Electronics
The application of anodized aluminum in consumer electronics stems from its advantages as compared to other materials. The following details are its benefits as well as practical uses:
Vickers Hardness (HV) 200 – 600
Improved scratch, mechanical, and wear resistance.
Long-lasting with mild abrasion.
Resistance to salt and humid weather.
Salt spray test endurance of over 200 to 500 hours without surface degradation.
Best for portable electronics with changing environmental exposure (smartphones, tablets).
Low weight of aluminum is maintained.
Best suited for ergonomic and portable design of the product without affecting structural integrity.
Surface dyeing increases design potential.
Branded professional look of the product casing and its accessories.
Enhanced convection due to improved surface emissivity.
Usually in devices that need high thermal regulation like laptops and gaming consoles.
Easily branded enabling coatings and paints due to porous anodized surfaces.
Improvements in durability of electronics against usage wear and time.
Anodized aluminum makes the manufacture of lightweight, durable, and consumer appealing electronics such as smartphones, laptops, and wearable devices easier.
Benefits of Architectural Metal Finishes
Owing to its aesthetic versatility and physical strength, anodized aluminium is one of the major architectural metals. The following details list its many benefits.
Aluminum has withstood the test of time for decades without losing its shape or aesthetics. Testing demonstrates that anodized coatings aged 25 years of outdoor exposure, especially when sealed to prevent contamination and moisture, preservation secured structural integrity.
The anodization treatment is effective in increasing surface protection against oxidation and corrosive elements. Some studies indicate that Aluminum can also withstand harsh environments such as salt spray for over 1000 hours without incurring corrosion damage compliant to ASTM B117 standards.
Combining modern methods to dye anodized aluminum during the anodization stage ensures maximum resistance to color fading. This is vital for external building cladding and facades which require strong resistance to UV radiation.
The eco-friendliness of anodized aluminum is striking as it can be recycled 100 percent. Its durability reduces maintenance efforts which increases the rate of replacements which in turn leads to certifications for eco-friendly buildings like LEED.
The increased effect of anodized surfaces on emmisivity assists in thermal control by enhancing energy efficiency when used in sunshades or panels set externally while also aiding in thermal regulation. Various laboratory studies suggest that unlike non-anodized metals, vertically mounted reflective exhaust systems tend to radiate and displace 15%-20% more heat than is required, depending on certain conditions.
These facts highlight the significance of anodized aluminum in architecture entails the alloying of finishing techniques because it combines use with ornamentation without neglecting ecological factors.
Frequently Asked Questions (FAQs)
Q: What is aluminum anodizing and why is it important?
A: Anodizing aluminum is an electrolytic process that increases the anodic oxide layer of aluminum anodizes protective coating which is hard and corrosion resistant. Not only does the process provide more protection from corrosion, but also helps in applying different colors for surface finish, which is both functional and appealing.
Q: How does the anodizing process work?
A: Anodizing involves immersing substrates, in this case aluminum, into electrolyte baths for anodizing, usually acids like sulfuric or chromic acid. Following this, an electric current is passed through the system, which leads to oxidation of part surface resulting in a porous oxide layer which can be colored using various dyes or sealed for better protection.
Q: What are the differences between type II and type III anodizing?
A: Type II anodizing also called as standard anodizing uses sulphuric acid for anodization and gets moderate level anodic coating thickness which is suitable for most of decorative and protective uses. Type III anodizing, also called hard anodizing results in thicker and more durable anodized coating which is very hard and resistant to abrasion and is commonly used in parts like automotive components.
Q: Can anodizing impact the electrical conductivity property of aluminum?
A: Indeed, anodizing impacts aluminum’s electrical conductivity. Designs which warrant that the metal is in a usable state where conductivity does not pose a challenge needs to pay close attention to where anodized coatings are utilized because anodized coatings serve as insulators which sever conductivity in metals.
Q: What are the advantages of anodized aluminum in comparison to untreated aluminum?
A: Unlike untreated aluminum, anodized aluminum provides several advantages. The anodic coating possesses superior resistance to corrosion, added surface hardness, and has the ability to accept most dyes. In addition, surfaces of metals which have undergone anodizing tend to have enhanced wear and abrasion resistance when compared to untreated aluminum.
Q: In what ways might the performance of the anodized metal be affected by the thickness of anodizing applied to it?
A: The performance of anodized metals, as well as their reliability and protective features, are deeply dependent on the sturdiness provided by the anodizing thickness. Metals with thicker anodic coatings tend to be shielded from corrosion and damage more than those with thinner coatings, thus making them ideal for harsh conditions. But, certain application conditions may have differing optimal thickness requirements that are not uniform across all applications.
Q: Are aluminum alloys able to undergo anodization?
A: Yes, it is possible to anodize aluminum alloys. The anodizing quality and peculiarity of the anodic coating can vary based on the alloy composition. Some alloys tend to produce better results when anodizing is applied, therefore, selection of the aluminum alloy has to be done with utmost care if certain results are aimed at.
Q: A help me understand, what is the purpose of anodizing bath in the process of anodizing?
A: The anodizing bath has significant importance in the anodizing process in that it stores the anodizing solution which is mostly an acidic medium like sulphuric or chromic acid. This bath is responsible for the electrochemical reaction that occurs to yield anodic coatings of aluminum. Significant changes in the features and the quality of the film forming on the substrate aluminum is highly possible with alterations in the composition and temperature of the bath.
Q: Is it possible to mechanically anodize stainless steel, or any other metal besides aluminum?
A: Anodizing does not apply to stainless steel; directly electrolytic oxidizing steel forms a coating that does not adhere to stainless steel. Unlike aluminum, stainless steel does not develop an anodic coating by electrolytic oxidation, and other techniques are employed to improve steel’s surface characteristics.
Reference Sources
1. “A Review on Anodizing of Aerospace Aluminum Alloys for Corrosion Protection”
- Authors: Mariana Paz Martínez-Viademonte, S. Abrahami, T. Hack, M. Burchardt, H. Terryn
- Publication Date: November 18, 2020
- Summary: This review discusses the anodizing process as a corrosion protection method for aerospace aluminum alloys. It highlights the importance of anodic oxide layers in enhancing corrosion resistance and structural integrity. The paper covers the principles of anodic oxide protection, the effects of anodizing parameters, and the challenges associated with chromic acid anodizing (CAA) and its environmentally friendly alternatives.
- Methodology: The authors conducted a comprehensive literature review, analyzing various studies on anodizing processes, parameters, and their effects on corrosion resistance in aerospace applications(Martínez-Viademonte et al., 2020).
2. “Influence of the Composition of Electrolyte for Hard Anodizing of Aluminum on the Characteristics of Oxide Layer”
- Authors: M. Student, I. Pohrelyuk, V. Hvozdetskyi, H. Veselivska, Kh. R. Zadorozhna, R. Mardarevych, Yu.V. Dzioba
- Publication Date: September 1, 2021
- Summary: This study investigates how different electrolyte compositions affect the characteristics of oxide layers formed during hard anodizing of aluminum. The findings indicate that the composition of the electrolyte significantly influences the thickness, hardness, and corrosion resistance of the anodized layer.
- Methodology: The authors performed experiments using various electrolyte compositions and analyzed the resulting oxide layers through techniques such as scanning electron microscopy (SEM) and electrochemical tests to evaluate their properties(Student et al., 2021, pp. 1–8).
3. “Dry Sliding Behavior of an Aluminum Alloy after Innovative Hard Anodizing Treatments”
- Authors: C. Soffritti, A. Fortini, Anna Nastruzzi, R. Sola, M. Merlin, G. L. Garagnani
- Publication Date: June 1, 2021
- Summary: This paper evaluates the tribological performance of anodized aluminum alloys subjected to different hard anodizing treatments. The study finds that innovative anodizing treatments can significantly improve the wear resistance and friction properties of aluminum alloys.
- Methodology: The authors conducted wear tests using a pin-on-disc tribometer and analyzed the microstructure and mechanical properties of the anodized layers using SEM and other characterization techniques(Soffritti et al., 2021).
