Introduction to Zinc Alloy

Zinc alloys are a group of versatile metal compositions that combine the element zinc with one or more other metals to enhance their physical, chemical, and mechanical properties. These alloys find wide-ranging applications across various industries, thanks to their unique characteristics and performance advantages. From well-known brass alloys to specialized zinc-based alloys like Zamak and ZA alloys, zinc alloys offer a diverse range of properties that make them suitable for applications such as casting, plating, forging, and even as biodegradable materials.

In this article, we will delve into the world of zinc alloys, exploring their definition, characteristics, properties, various types, and extensive range of applications. Additionally, we aim to provide you with valuable insights by addressing frequently asked questions, enabling you to develop a deeper understanding of zinc alloys. the picture on the left shows some common zinc alloy products, which can be customized to your specifications through our convenient online CNC machining services.

What Is Zinc Alloy?

Zinc alloys are metal compositions that incorporate zinc as the primary constituent, often combined with other metals. These alloys exhibit a range of desirable properties, including high strength, hardness, and excellent electrical conductivity. They are particularly well-suited for casting processes, allowing the creation of intricate and multi-faceted shapes with high dimensional accuracy.

Zinc alloys are commonly used in various industries due to their structural integrity and ability to form complex shapes. When used in die casting, alloy zinc is often alloyed with aluminum, copper, and magnesium, with other elements considered impurities and limited within specified ranges. Zinc-based alloys are favored for die casting due to their high ductility, excellent impact strength, and the ease of achieving thin walls and smooth surfaces for subsequent plating and painting.

What Is the History of Zinc Alloy?

Zinc alloys have a rich history, with their development dating back to the 1950s and 1970s, pioneered by companies such as Noranda, New Jersey Zinc Co. Ltd., St. Joe Mineral Co., and the International Lead Zinc Research Organization (ILZRO). These alloys were created to compete with bronze, cast iron, and aluminum, offering high strength, excellent bearing properties, and lower energy requirements for melting, making them suitable for various casting methods.

On the other hand, the development of zinc alloy has brought significant benefits to various industries. Its excellent mechanical properties make it irreplaceable in the manufacturing industry. In addition, the versatility of zinc-alloy allows the production of parts with complex shapes and high dimensional accuracy. For example, most of the CNC car parts we often make are made of zinc alloy.

What Is the Other Term for Zinc Alloy?

Another term for zinc alloy is “pot metal.” “Pot metal” is a colloquial term used to describe low-melting-point alloys that often contain zinc as the primary component. These alloys are melted and cast in a pot or crucible and are known for their affordability and ease of casting.

What Is Zinc Alloy Made Of?

Zinc alloys are typically composed of zinc as the primary component combined with other metals. Commonly used alloying elements include aluminum, copper, magnesium, and traces of other metals. These additional elements help enhance the strength, hardness, corrosion resistance, and other desired characteristics of the zinc alloy.

How Is Zinc Alloy Made?

Zinc alloys are typically made through a process called alloying, where zinc is combined with other metals to achieve the desired composition and properties.

One common technique for making zinc alloys is melting and mixing. The alloying elements, such as aluminum, copper, and magnesium, are added to molten zinc in precise proportions. The mixture is then thoroughly stirred or agitated to ensure homogeneity. This molten alloy is then cast into the desired shape using various casting methods like die casting, investment casting, or sand casting.

Another method is the pre-alloying process, where the alloying elements are combined with zinc in solid form. This is typically done by melting or sintering zinc with the alloying elements. The resulting pre-alloyed material is then further processed, such as through melting or powder metallurgy techniques, to create the final zinc-alloy.

How Is Zinc Alloy Processed?

Zinc alloys undergo various processing techniques to shape them into desired forms and enhance their properties. Here are some common processes used for zinc alloy processing:

1. Die Casting

Die casting is a popular method for shaping zinc alloys. Molten zinc alloy is injected under high pressure into a steel mold or die. The alloy rapidly solidifies within the die, creating the desired shape. Zinc die casting allows for the production of complex and precise zinc die parts with high dimensional accuracy.

2. Investment Casting

Also known as lost wax casting, investment casting involves creating a wax pattern of the desired part. The wax pattern is then coated with a ceramic shell, and the wax is melted out, leaving a cavity. Molten zinc alloy is poured into the cavity, filling the space. Once cooled and solidified, the ceramic shell is removed, revealing the final cast part.

3. Sand Casting

Sand casting involves creating a mold using a mixture of sand and a binder. The mold is formed by compacting the sand mixture around a pattern of the desired part. Molten zinc alloy is then poured into the mold, allowing it to solidify. After cooling, the mold is broken away, and the cast part is obtained. Sand casting is suitable for larger and less intricate components.

4. Machining

Machining processes, such as milling, drilling, and turning, can be used to shape and refine zinc alloy parts. Machining is commonly employed to achieve tight tolerances, fine details, and specific surface finishes on cast or forged zinc alloy components.

5. Surface Treatment

Zinc alloys can undergo surface treatments to enhance their appearance, corrosion resistance, or other properties. Common surface treatments include plating (such as chrome or nickel plating), painting, powder coating, and anodizing.

These processing techniques allow for the creation of a wide range of zinc alloy components used in various industries, including automotive, electronics, construction, and more.

What Are the Characteristics of Zinc Alloy?

Zinc alloys possess several characteristics that make them desirable for a wide range of applications. Here are some key characteristics of zinc alloys:

1. Excellent Castability: Zinc alloys have excellent fluidity and low melting points, making them highly castable. They can be easily molded into intricate shapes and thin-walled structures, allowing for the production of complex parts with high dimensional accuracy.

2. Good Strength: Zinc alloys offer good strength and hardness, comparable to some other non-ferrous metals. They can withstand moderate loads and provide structural integrity for various applications.

3. Corrosion Resistance: Zinc alloys exhibit excellent corrosion resistance, particularly when compared to other base metals. This corrosion resistance is further enhanced by the formation of a protective oxide layer on the surface of the alloy, which helps to prevent further oxidation.

4. Enhanced Surface Finish: Zinc alloys can achieve smooth and aesthetically pleasing surface finishes. They are often used for decorative applications where a high-quality appearance is desired. Zinc alloys can be easily plated with various metals to further enhance their surface properties.

5. High Thermal and Electrical Conductivity: Zinc alloys have good thermal and electrical conductivity, enabling efficient heat dissipation and electrical conductivity in applications that require such properties.

6. Good Casting and Joining Properties: Zinc alloys have low melting points, which allow for cost-effective casting processes such as die casting and investment casting. They also exhibit good joining properties, enabling easy welding, soldering, and brazing.

7. Recyclability: Zinc alloys are highly recyclable, and the recycling process consumes significantly less energy compared to primary production. This makes zinc alloys an environmentally friendly choice.

What Color Is Zinc Alloy?

Without any processing, zinc alloy will show the same bright silver tone as zinc, but many times the zinc alloys we see contain other metals or additives, so some zinc alloys will show other colors.

What Does Zinc Alloy Look Like?

Zinc alloys have a metallic appearance similar to other metals. In their raw form, zinc alloys typically have a bright silver color, resembling the appearance of pure zinc. However, some zinc alloys may have a slightly bluish or yellowish tint due to the presence of other alloying elements. The surface finish of zinc alloys can range from smooth and polished to textured, depending on the manufacturing process and any post-processing treatments.

Additionally, zinc alloys can be further customized with various surface treatments, such as plating or painting, which can provide a wide range of colors and finishes, including silver, gold, black, or other shades. The final appearance of a zinc alloy is influenced by factors such as its composition, processing techniques, and any additional surface treatments applied to meet specific functional or aesthetic requirements. The image below shows an example of a zinc alloy:


What Are the Different Types of Zinc Alloys?

There are numerous types of zinc alloys available, each with its own unique composition and specific properties. Here are some different types of zinc alloys:

1. Zamak Alloys

Zamak alloys are a family of zinc alloys that contain aluminum, magnesium, and copper as the primary alloying elements. The most common Zamak alloys include Zamak 3, Zamak 5, and Zamak 2, which offer a balance of strength, castability, and dimensional stability.

2. ZA Alloys

ZA alloys, also known as zinc-aluminum alloys, are zinc alloys that contain higher aluminum content compared to Zamak alloys. ZA alloys provide improved mechanical properties, including higher strength, hardness, and wear resistance. Common examples include ZA-8, ZA-27, and ZA-12.

3. Zinc-Copper Alloys

These alloys primarily consist of zinc and copper, with copper content ranging from a few percentage points to over 30%. Zinc-copper alloys offer enhanced strength, corrosion resistance, and electrical conductivity. They are commonly used in electrical and electronic applications.

4. Zinc-Nickel Alloys

Zinc-nickel alloys are zinc-based alloys that contain a significant amount of nickel. These alloys provide excellent corrosion resistance, even in harsh environments. They are frequently used in industries such as automotive, aerospace, and electronics.

5. Zinc-Tin Alloys

Zinc-tin alloys combine zinc with tin as the primary alloying element. These alloys offer improved casting properties and are often utilized in die-casting applications where high fluidity and dimensional accuracy are required.

6. Other Custom Alloys

In addition to the mentioned alloys, there are various custom zinc alloys tailored for specific applications. These alloys can include additional elements such as lead, bismuth, or silver to impart specific properties like improved machinability or enhanced melting range.

What Are the Properties of Zinc Alloy?

There are many types of zinc alloys. Each zinc Alloy contains different alloy components and will exhibit different properties. In the table below, we summarize some common general properties of alloy zinc:

What Are the Physical Properties of Zinc Alloy?

The table below lists some physical properties of zinc alloy:

Zinc Alloy Physical Properties Table
AlloyMelting Point (°C)Density (g/cm³)Hardness (Brinell)Tensile Strength (MPa)Yield Strength (MPa)Elongation (%)Thermal Conductivity (W/(m·K))Electrical Conductivity (% IACS)Coefficient of Thermal Expansion (x10^(-6) /°C)Examples of Applications
Zamak 3385-3906.682-91230-270150-200 2-51132727.4Automotive parts, electrical connectors, consumer goods
Zamak 5380-3866.685-96290-320230-260 2-51092726.7Hardware, structural components, electrical components
Zamak 2380-3866.7105-125280-320220-250 2-51052727.4Brackets, handles, fittings
ZA-8 (Zamak 8)365-3856.580-90250-290170-220 2-51162927.4Industrial machinery components, automotive parts
ZA-27480-4956.4130-160310-365200-230 2-51162526.7Gears, brackets, marine components
ZA-12375-3906.780-100235-275150-180 2-51132626.7Pump housings, valve bodies, electrical connectors

What Are the Chemical Properties of Zinc Alloy?

The table below lists some chemical properties of zinc alloy:

Zinc Alloy Chemical Property Table
AlloyCompositionCorrosion ResistanceGalvanic Compatibility
Zamak 34% Aluminum, 1% CopperGoodGood
Zamak 54% Aluminum, 1% Copper, 0.03% MagnesiumGoodGood
Zamak 23% Aluminum, 3% CopperGoodGood
ZA-8 (Zamak 8)8% Aluminum, 3% CopperGoodGood
ZA-2727% Aluminum, 2.2% CopperExcellentGood
ZA-1212% Aluminum, 3% CopperGoodGood

What Are the Mechanical Properties of Zinc Alloy?

The table below lists some mechanical properties of zinc alloy:

Zinc Alloy Mechanical Properties Table
AlloyTensile Strength (MPa)Yield Strength (MPa)Hardness (Brinell)Elongation (%)
Zamak 3230-270150-20082-91 2-5
Zamak 5290-320230-26085-96 2-5
Zamak 2280-320220-250105-125 2-5
ZA-8 (Zamak 8)250-290170-22080-90 2-5
ZA-27310-365200-230130-160 2-5
ZA-12235-275150-18080-100 2-5

What Are the Benefits of Zinc Alloys?

Zinc alloys offer several benefits, making them a popular choice in various applications. Here are some of the advantages of zinc alloys:

1. Excellent castability: Zinc alloys can be easily molded into complex shapes and intricate details with high precision, making them suitable for intricate parts and components.

2. Good dimensional stability: Zinc alloys exhibit minimal shrinkage during solidification, resulting in excellent dimensional stability. This property allows for close tolerances and consistent part dimensions, reducing the need for additional machining or post-processing operations.

3. Corrosion resistance: Zinc alloy’s natural formation of a protective zinc oxide layer on the surface helps prevent corrosion and extends the lifespan of the parts.

4. Excellent finishing characteristics: Zinc alloys readily accept a variety of surface finishes, including plating, painting, and powder coating. They have good adhesion properties, allowing for high-quality finishes with enhanced aesthetics and protection against corrosion.

5. High strength-to-weight ratio: Zinc alloys offer a favorable strength-to-weight ratio, meaning they provide good strength and mechanical properties while being relatively lightweight. This property makes them advantageous for applications where weight reduction is desired without compromising structural integrity.

6. Good electrical conductivity: Zinc alloys, especially those with copper as an alloying element, exhibit good electrical conductivity. This makes them suitable for applications where electrical conductivity is required, such as electrical connectors and components.

7. Cost-effectiveness: Zinc alloys are cost-effective compared to many other metals and alloys. The abundance of zinc as a raw material, combined with its ease of processing and recyclability, contributes to its affordability.

What Are the Limitations of Zinc Alloys?

Zinc alloys, while versatile and widely used, do have some limitations. Here are a few of them:

1. Low melting point: One limitation of zinc alloys is their relatively low melting point compared to other metals. This can restrict their use in high-temperature applications where the operating temperatures exceed the alloy’s melting point.

2. Limited strength at elevated temperatures: Zinc alloys tend to experience a significant reduction in strength and hardness when exposed to high temperatures. This can limit their suitability for applications that require high mechanical properties in elevated temperature environments.

3. Susceptibility to corrosion: While zinc alloys offer good corrosion resistance in many environments, they can still be susceptible to certain types of corrosion, such as galvanic corrosion when in contact with dissimilar metals. Proper coatings or surface treatments may be required to enhance their corrosion resistance in specific applications.

4. Limited load-bearing capabilities: Compared to some other metals, zinc alloys generally have lower strength and load-bearing capabilities. They may not be suitable for applications that require high structural integrity or heavy load-bearing capacities.

5. Limited wear resistance: Zinc alloys may exhibit lower wear resistance compared to some other metals and alloys. In applications where components are subjected to significant friction or abrasive wear, additional protective measures or alternative materials may be more suitable.

It’s important to note that the limitations mentioned above are general and can vary depending on the zinc alloy’s specific composition, processing, and application. Despite these limitations, zinc alloys are widely used in numerous industries due to their favorable combination of properties and cost-effectiveness.

What Is Zinc Alloy Used for?

Zinc alloys find application in various industries and sectors due to their favorable properties. Here are some common uses of zinc alloys:

1. Automotive industry

Zinc alloys are widely used in the automotive industry for parts and components such as door handles, locks, brackets, fuel system components, and interior trims. Their combination of strength, corrosion resistance, and cost-effectiveness makes them suitable for these applications.

2. Electrical and electronics

Zinc alloys are utilized in electrical and electronic applications where good electrical conductivity, corrosion resistance, and dimensional stability are required. Examples include connectors, sockets, switches, circuit breakers, and various housings for electronic devices.

3. Construction and architecture

Zinc alloys are used in the construction industry for architectural applications such as window frames, door frames, hardware, and decorative elements. Their corrosion resistance and ability to be easily formed into complex shapes make them suitable for such applications.

4. Consumer goods

Zinc alloys are commonly found in a wide range of consumer goods, including furniture hardware, bathroom fixtures, kitchen appliances, and decorative accessories. Their ability to be cast into intricate designs, combined with good corrosion resistance, makes them popular in these applications.

5. Medical equipment

Zinc alloys are utilized in medical equipment and devices due to their biocompatibility, dimensional accuracy, and ease of sterilization. They can be found in components such as surgical instruments, orthopedic implants, and dental equipment.

6. Defense and aerospace

Zinc alloys are used in defense and aerospace applications where lightweight materials with good strength and corrosion resistance are required. They can be found in components such as aircraft fittings, fasteners, and ammunition casings.

7. Marine industry

Zinc alloys are employed in the marine industry for applications that require corrosion resistance in saltwater environments. They are used in marine hardware, fittings, and components exposed to seawater or harsh marine conditions.

What Type of Metal Is Zinc Alloy?

Zinc alloy is a non-ferrous metal alloy. It is primarily composed of zinc as the base metal, along with other alloying elements. Non-ferrous metals are metals that do not contain iron as the primary component.

What Is Stronger Zinc Alloy or Stainless Steel?

Stainless steel generally offers higher strength compared to zinc alloy. Stainless steel is a robust alloy that combines iron, chromium, and other elements, providing superior mechanical properties and durability. It is commonly used in applications requiring high strength and resistance to corrosion, such as structural components and industrial equipment. Zinc alloys, on the other hand, offer moderate strength and are valued for their castability, corrosion resistance, and cost-effectiveness rather than exceptional strength. While both materials have their respective advantages, stainless steel generally exhibits greater strength characteristics.

What Is the Difference Between Zinc Alloy and Nickel-free?

Zinc alloy and nickel-free refer to different aspects of materials, particularly about allergies and sensitivities:

Zinc alloy refers to a type of metallic material composed mainly of zinc, while nickel-free refers to materials or products that do not contain nickel or contain only minimal amounts to prevent allergic reactions in individuals sensitive to nickel.

What Does a Zinc Alloy Have to Do with Brass?

Brass and zinc alloy are related because brass is a type of zinc alloy. Brass is a metallic alloy that is primarily composed of copper and zinc. The exact composition of brass can vary, but it typically contains around 60-80% copper and 20-40% zinc. The addition of zinc to copper alters the properties of the alloy, making it more malleable, corrosion-resistant, and suitable for various applications. Brass is valued for its attractive golden color, durability, and versatility. It is commonly used in musical instruments, plumbing fittings, decorative hardware, and electrical connectors, among other applications. So, in essence, zinc alloy is an integral part of brass composition.

Which Zinc Alloy Is Best for Prototyping?

When it comes to choosing a zinc alloy for prototyping, Zamak alloys are often considered a popular choice. Zamak is a family of zinc alloys that typically contain varying amounts of aluminum, copper, and sometimes smaller additions of other elements. Zamak alloys are known for their good castability, dimensional stability, and excellent surface finish, making them suitable for prototyping applications. Zamak 3, in particular, is commonly used for prototyping due to its balance of strength, hardness, and ease of casting. It is often selected for its ability to replicate fine details and intricate shapes accurately.

Is Zinc Alloy Heavier than Aluminum?

Yes, zinc alloy is generally heavier than aluminum. The density of zinc is higher than that of aluminum, which means that a given volume of zinc alloy will weigh more than the same volume of aluminum. This is one of the reasons why aluminum is often chosen for applications where weight reduction is a priority, such as in the automotive and aerospace industries. Aluminum’s lightweight nature, combined with its favorable strength-to-weight ratio, makes it a preferred choice for many applications that require a balance between strength and weight.

Is Zinc Alloy Stronger than Aluminum?

Zinc alloy is generally not as strong as aluminum. Aluminum is known for its favorable strength-to-weight ratio, offering good mechanical properties and high strength. It is widely used in applications that require structural integrity and load-bearing capabilities. On the other hand, while zinc alloys can exhibit reasonable strength properties, they generally do not possess the same level of strength as aluminum.

Is Zinc Alloy Stronger than Brass?

Yes, Zinc alloy is generally stronger than brass. While brass exhibits good strength and hardness, zinc alloys tend to have higher strength properties.

Is Zinc Alloy Stronger than Steel?

Zinc alloy is generally not stronger than steel. Steel is known for its exceptional strength properties, making it one of the strongest and most widely used construction materials. Steel alloys are composed primarily of iron, with small amounts of carbon and other alloying elements. On the other hand, while zinc alloys can exhibit reasonable strength properties, they generally do not possess the same level of strength as steel.

Is Zinc Alloy the Same As Pewter?

No, zinc alloy is not the same as pewter. Pewter is a specific type of alloy that traditionally consists primarily of tin, along with small amounts of copper, antimony, and other metals. It has a low melting point and is known for its malleability, making it easy to work with for various applications such as decorative items, jewelry, and tableware.

Zinc alloy, on the other hand, refers to a group of alloys that have zinc as the primary base metal, often combined with other elements such as aluminum, copper, and magnesium. Zinc alloys offer a range of properties and are commonly used in various industries, including automotive, electronics, and manufacturing.

While both pewter and zinc alloy contain zinc as an ingredient, they have different compositions, melting points, and applications. Pewter has a higher tin content and is generally used for its aesthetic appeal, while zinc alloys are valued for their mechanical properties, corrosion resistance, and cost-effectiveness in a wide range of applications.


This article serves as a comprehensive introduction to zinc alloy, covering its definition, wide range of applications, and notable advantages. Additionally, we have included a section of frequently asked questions (FAQs) to provide further insights. If you have any inquiries or require additional information, please don’t hesitate to reach out to our team.

At Ruitai, we offer extensive manufacturing capabilities and provide value-added services to cater to all your prototyping and production needs. We are pleased to offer you a complimentary quote at your convenience. Feel free to get in touch with us for any inquiries or to discuss your requirements.


We would like to emphasize that the data content presented in this article is intended for reference purposes only. The information provided is based on our current knowledge and is offered in good faith. However, Ruitai Mould cannot guarantee the completeness, accuracy, or validity of the information provided, either explicitly or implicitly.

Addressing Common Zinc Alloys Questions:

Q1: Does zinc alloy tarnish?
A1: Zinc alloy can tarnish over time, especially when exposed to air, moisture, and certain chemicals.

Q2: Does zinc alloy rust?
A2: Zinc alloy itself does not rust, as rust refers specifically to the oxidation of iron and steel. However, if the zinc coating or protective layer on the alloy gets damaged, it can lead to corrosion.

Q3: Does zinc alloy turn green?
A3: Zinc alloys, when exposed to certain environmental conditions, can develop a greenish patina or corrosion layer, similar to what is commonly seen with brass or copper.

Q4: Does zinc alloy have nickel?
A4: Zinc alloy can contain small amounts of nickel, depending on the specific composition of the alloy. However, nickel is not typically a primary component of zinc alloys.

Q5: Does saltwater cause zinc alloy to rust?
A5: Saltwater can accelerate the corrosion process of zinc alloy, potentially leading to rust or corrosion if the protective layer on the alloy is damaged.

Q6: Does zinc alloy change colors with wear?
A6: Zinc alloy can undergo color changes with wear, especially if the surface coating or finish is subject to abrasion or chemical reactions.

Q7: Is zinc alloy safe?
A7: Zinc alloy is generally considered safe for common applications.

Q8: Is zinc alloy strong?
A8: Zinc alloy has moderate strength properties, but it is generally not as strong as materials like steel or some other metals.

Q9: Is zinc alloy magnetic?
A9: Zinc alloy is not typically magnetic, as it does not contain magnetic elements like iron or nickel.

Q10: Is zinc alloy waterproof?
A10: Zinc alloy is not inherently waterproof. It can be susceptible to corrosion and damage when exposed to moisture and certain environmental conditions.

Q11: Is zinc alloy a good metal?
A11: Zinc alloy has its own set of advantages and applications. It offers good castability, and corrosion resistance, and can be cost-effective for various industries and purposes.

Q12: Is zinc alloy durable?
A12: Zinc alloy can be durable depending on the specific application and conditions. It can withstand normal wear and tear, but it may not be as durable as some other metals in certain demanding environments.

Q13: Is zinc alloy a composite?
A13: Zinc alloy is not considered a composite material. It is a solid alloy made by combining zinc with other elements.

Q14: Is zinc alloy a precious metal?
A14: No, zinc alloy is not considered a precious metal. Precious metals typically include gold, silver, and platinum.

Q15: Is zinc alloy conductive?
A15: Zinc alloy has relatively low electrical conductivity compared to other metals such as copper or aluminum. However, it can still conduct electricity to some extent.

Q16: Is zinc alloy corrosion-resistant?
A16: Zinc alloy can exhibit good corrosion resistance, particularly when a protective layer or coating is applied. However, it may not be as corrosion resistant as some other metals or alloys.

Q17: Is zinc alloy ferrous?
A17: No, zinc alloy is not ferrous. Ferrous metals contain iron, whereas zinc alloy is primarily composed of zinc with other non-ferrous elements.

Q18: Is zinc alloy sustainable?
A18: Zinc is a naturally abundant element, and zinc alloy can be recycled. Therefore, it can be considered a sustainable material option.

Q19: Is zinc alloy weldable?
A19: Zinc alloy can be challenging to weld due to its low melting point and potential for vaporization during welding.

Q20: Can you silver plate zinc alloy?
A20: Yes, zinc alloy can be silver plated through electroplating processes. Silver plating can enhance the appearance and provide additional corrosion resistance.

Q21: Can zinc alloy be anodized?
A21: No, zinc alloy cannot be anodized in the same way as aluminum. Anodizing is a specific electrochemical process applicable to aluminum and some other metals but not zinc alloys.