Copper Forging Guide

01 Jan.,2024

 

Copper has been used by humans for thousands of years and is one of the earliest metals to be discovered and utilized in a variety of applications. 

Evidence suggests that copper was being used as early as 10,000 years ago. 

Copper is an ideal metal to work with—it can be easily shaped into tools for a variety of purposes. 

Its abundance in nature also makes it relatively easy to access and its low melting point allows it to be melted down quickly and efficiently. 

By far the easiest method to manufacture metal products and parts with copper is through forging since the process allows for higher precision in creating various shapes due to the controlled deformation of the metal when it is forged. 

Additionally, because only small amounts of force are required during the forging process, there is less distortion or warping, which results in better accuracy than with many other production techniques.

In this guide, we will go over some of the major topics concerning copper forgings, including the copper forging process, the types of alloys used, as well as the properties and applications of copper forgings.

What Are the Types of Copper Alloys Used in Forging

The most common type of copper alloy used in forging is brass, which is made from a combination of copper and zinc. 

Brass is highly resistant to corrosion and can be easily molded into intricate forms, making it an ideal choice for forging products.

Another widely used copper alloy that is frequently forged is bronze—it consists of copper combined with tin and sometimes contains other metals like aluminum or silicon. 

Bronze has excellent wear-resistance properties, making it suitable for manufacturing items that require long-term durability.

Other copper alloys that are well-suited for forging include:

  • High copper
  • Leaded copper
  • Copper-nickel
  • Nickel-silver

A short description of each is given below.

High Copper Alloys

These alloys are mostly composed of copper (at least 94%), with a little bit of silver and tin added in.

High copper alloys are known for their exceptional strength, durability, and corrosion resistance. 

Other elements, such as zinc, nickel, iron, and aluminum, may be added to enhance the strength and corrosion resistance of these alloys further while still allowing them to maintain good electrical conductivity.

Leaded Copper

Leaded copper is mostly made up of copper and lead, yet it can be combined with other metals such as zinc, aluminum, tin, or nickel as well. 

It is commonly used in electrical applications since it has very good thermal and electrical conductivity. 

Adding lead to copper adds several benefits, such as increased strength and improved workability. 

Since leaded copper offers superior machining properties, it is suitable for use in precision engineering applications, where accurate shapes need to be formed quickly. 

However, due to its lead content, it may not be suitable for certain applications where contact with food is required, as trace amounts of lead can be toxic if ingested.

Copper-Nickel

As the name suggests, copper-nickel is made from both copper and nickel. This alloy has a unique set of properties that make it ideal for marine applications.

Due to its resistance to saltwater corrosion, copper-nickel can be used to manufacture many marine components and for ship repairs.

Copper-nickel forgings are strong and durable, yet they also tend to be lightweight. 

Moreover, they resist many forms of corrosion and remain sturdy at very high temperatures (up to 750 °F, or 400 °C).

Nickel-Silver

Nickel-silver is a copper-nickel-zinc alloy. It has been used for centuries in the manufacturing of coins, jewelry, and other items due to its distinctive metallic color.

Due to its strong resemblance to sterling silver, the alloy is also known as German silver, despite containing no actual silver. 

Unlike sterling silver, this copper alloy will not corrode when exposed to water or air, making it ideal for outdoor applications.

Nickel-silver is often referred to as an “anti-tarnish” alloy because it resists tarnishing and corrosion more than other copper alloys such as brass or bronze. 

The material’s composition makes it highly malleable under heat, making it easier to forge than many other metals with similar properties.

The above-mentioned copper alloys lend themselves well to forging due to their malleability, durability, availability, and cost-effectiveness. 

Furthermore, even though they come in many different colors and strengths, the forging process for each one is generally the same. 

How Is Copper Forged

The copper forging process involves the application of heat and pressure to manipulate copper into the desired shape. 

While there are different methods to forge copper alloys, they will almost always follow the following steps:

  1. A die is created from a block of metal that has been cut into the desired shape and size. 
  1. The die is heated to a temperature between 1350-1700 °F (732-927 °C) before being placed on top of hot copper ingots. 
  1. A hammer is used to strike down on the ingots, forcing them into the desired shape, while also increasing the volume and changing the internal grain structure.

Typically, after these three steps, the shaped copper goes through a heat treatment process. The most common types are annealing, tempering, solutionizing, quenching, and aging.

A brief explanation of each is given below:

Annealing

During annealing, the material is heated and then slowly cooled to soften it, improve its ductility, and reduce or eliminate stresses caused by plastic deformation or machining operations.

Tempering

Tempering involves heating a material to a specific temperature, then cooling it quickly with water or oil.

It is similar to annealing but involves heating the material at lower temperatures to reduce brittleness while maintaining strength.

Solutionizing

This process involves heating an alloy above its solvus temperature, which causes insoluble constituents to dissolve into the material’s matrix. 

In this way, the process can modify alloy composition as well as grain size and structure.

Quenching

Quenching heat treatment involves rapidly cooling the material in oil or water after it has been heated to a specific temperature for a defined period of time. 

This helps increase the strength of metals by hardening the microstructure, making them more resistant to fracture and wear.

Aging

Aging is a thermochemical process used to improve the physical properties of metals and alloys. 

The process involves heating a metal or alloy to a specific temperature for an extended period of time, usually followed by cooling at a slower rate than normal tempering processes. 

This allows the grains and precipitates within the material’s microstructure to rearrange themselves and create more uniform grain sizes.

Each of the above heat treatment methods requires a cooldown period to avoid brittleness.

Forging copper and applying any of the heat treatments previously listed is a proven strategy to enhance and increase the properties of the forged copper and its various alloys. 

What Are the Properties of Copper Forgings

The properties of copper forgings are diverse and depend on the copper alloy selected, as well as the intended application for the part being forged. 

Many copper forgings undergo additional treatments like heat treatment or surface hardening to further enhance their performance in service.

A breakdown of the physical, mechanical, and chemical properties of forged copper is given below.

  • Good tensile strength
  • High machinability
  • Durability
  • Malleability
  • Ductility
  • Flexibility
  • Formidability
  • Lightweight
  • Thermal conductivity
  • Electrical conductivity
  • Corrosion-resistant properties (copper oxide) 
  • Cost-effective
  • Non-magnetic
  • Non-sparking
  • Antimicrobial 

All these beneficial properties make forged copper an ideal choice for many custom metal parts projects.

What Are the Applications of Copper Forgings

The most common uses for copper forgings include plumbing fixtures, electrical connectors, and vessels for the transportation of liquids, such as pumps and valves. 

Copper forgings are also often used to manufacture radiators, heat exchangers, and cooling systems due to their superior heat transfer capabilities.

Additionally, copper forgings are strong, reliable, and can be formed into a variety of shapes and sizes. 

Because of this, industries such as electronics, plumbing, aerospace and automotive industries, oil and gas extraction, and power generation use them extensively for a variety of applications.

A list of copper alloy forging applications within these industries is given below:

  • Generator components
  • Electrical wiring
  • Aircraft engine components
  • Motor assembly parts
  • Car suspension parts
  • Compression systems
  • Hollow insulators
  • Wind turbines
  • Industrial pumps
  • Busbars
  • Pipes
  • Valves
  • Fittings
  • Fixtures
  • Tubes

As can be seen from the above list, forged copper is often used in components that require high precision and strength. 

The popularity of copper forgings within the industries previously mentioned has also led other industries to explore their uses in their applications.

Industries where accuracy and hygiene are key to success such as robotics and medical equipment, are finding copper forgings to be extremely beneficial. 

As manufacturing technology continues to advance and more enhanced metallurgic processes become available, copper forgings are likely to be used in an increasing number of applications.

Conclusion

Copper forging is an excellent way to craft custom metals for many different kinds of projects. 

Getting the best results requires a great deal of skill and precision. 

Nevertheless, with the right tools and forging techniques, manufacturers can create strong and durable components that work efficiently in corrosive environments and handle strong electrical currents with ease. 

With this guide, we’ve attempted to increase your understanding of the different kinds of copper forgings. 

We hope it’s given you useful insights into their properties and applications and the ways in which they can meet your particular project requirements. 

Now that you have a more in-depth knowledge of the copper forging process and copper forgings in general, why not call an expert metal manufacturer who specializes in copper forging fabrication and give it a try?

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