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What Is Copper CNC Machining?
Copper CNC machining involves using computer-controlled tools and machines to fabricate copper materials into desired shapes. The CNC machining process controls complex devices such as mills, grinders, and lathes to make precise and intricate features on copper parts.
Copper is written as Cu and listed as atomic number 29 on the periodic table. It is second only to silver and offers excellent heat and electrical conductivity. It is also antimicrobial and corrosion-resistant, making it an ideal material for different aerospace, automotive, power, and medical applications. The commercially available copper is usually more than 99% pure and 1% impurities, including silver, lead, or oxygen.
Various Grades of Copper for CNC Machining
Copper materials are one of the main categories of commercial metals. Besides, there are various grades of copper materials available for CNC machining. However, these copper grades possess varying properties and compositions, making them suitable for specific machining projects. Consequently, choosing the ideal material for your project may be challenging since you must consider different factors.
The first step in copper CNC machining is to identify the material with the required properties for your copper machined parts. This section discusses the various grades of copper for CNC machining:
Pure Copper
These are typically soft and malleable copper materials. You can add different alloying elements in small volumes to form the dilute grade of pure copper. The alloying modifies one or more primary properties of pure copper to preferred forms. Besides, you can add other alloying elements to the pure copper grade to enhance their toughness.
You’ll find 0.7% total impurities in the composition of commercially pure copper grades. They have UNS designation numbers C10100 to C13000, depending on the elements added and impurity level.
However, pure copper is perfect for creating electrical components like wiring and motors. This grade of copper is also applicable in industrial machining for manufacturing heat exchangers.
Electrolytic Copper
Electrolytic copper materials are originally from cathode copper. As such, cathode copper is a copper with 99.95% purity, processed through electrolysis. Usually, the electrolysis process involves putting copper compounds into a solution and applying sufficient electricity to purify the copper material.
Consequently, most electrolytic copper materials have lower impurities than other copper grades. The most common electrolytic copper material is the C11000. It comprises less than 50 parts per million metallic impurities such as sulfur.
Besides, they possess about 100% IACS (International Annealed Copper Standard) and high electrical conductivity. However, electrolytic copper grades exhibit remarkable ductility, making them perfect for electrical applications such as busbars, windings, wires, and cables.
Oxygen-Free Copper
This grade of copper has the highest purity, containing little to no oxygen content. Oxygen-free copper grades are suitable for electrical copper components due to their high conductivity. As such, the high electrical conductivity of these copper materials makes them ideal for high vacuum electronics. However, C10100 and C10200 are typical examples of this copper grade.
- C10100, or Oxygen-free electronic (OFE), is a pure copper containing about 0.0005% oxygen. Also, it is more expensive than other oxygen-free copper grades.
- C10200, or Oxygen-free (OF), contains 0.001% oxygen content. It offers high electrical conductivity with precisely 100% IACS an equivalent to electrolytic copper materials.
Manufacturers use high-quality cathode copper to create oxygen-free copper materials through induction melting. This production process involves melting the cathode under non-oxidizing conditions created by graphite bath covering. Thus, it reduces the hydrogen content in the working environment.
Free-Machining Copper
Free-machining copper material contains different alloying elements. Typical alloying elements of this copper alloy include zinc, nickel, phosphorous, and tin. These elements further enhance this copper grade’s machinability.
Moreover, brass and bronze are copper alloys and are significant constituents of free-machining copper materials. Brass comprises zinc and copper, offering excellent workability and corrosion-resistant properties.
On the other hand, bronze is an alloy containing tin, copper, and phosphorus with remarkable impact strength and hardness. Free machining coppers are well-suited for extensive copper parts machining range. These include gears, coins, automotive hydraulics, torches, machined electrical components, etc.
The Advantages and Challenges of Copper in CNC Machining
Copper is a versatile CNC machining material compatible with various applications across industries. However, like other metallic materials, copper and its alloys have specific benefits and setbacks in CNC machining. These include:
Advantages
Below are the common benefits of copper machining:
- Copper materials exhibit good formability in cold and hot processes.
- Various cost-effective surface finish treatments work well with CNC-machined copper parts.
- CNC machining copper alloys exhibit high electrical and thermal conductivity and chemical and wear resistance.
- CNC copper parts offer impressive impact strength, ductility, and machinability.
Challenges
The limitations of Copper CNC machining include the following:
- Certain copper materials are incompatible with processes such as coated metal arc welding, spot welding, etc.
- Some copper parts are vulnerable to corrosion in environments with reactive substances due to copper grades’ varying corrosion resistance properties.
Key Considerations for Successful CNC Copper Machining
As the demand for CNC copper parts continues to increase, there are vital tips for successful CNC copper machining. Here are some of these factors in detail:
Choosing the Right Copper Grade
It is crucial to pick the ideal copper material grade most suitable for the intended application before CNC copper machining. For instance, using pure copper to make mechanical components is inappropriate and costly.
However, free-machining copper is the better option due to its cost-effectiveness and excellent machinability. Therefore, it would help to evaluate your copper parts requirements to choose the correct grade for machining.
Design for Manufacturability
Another primary consideration is examining your copper parts’ design requirements and specifications before CNC machining. This ensures your manufactured copper part achieves the required functionality.
As a general thumb rule, employ and maintain a 0.05mm minimum wall thickness in machining aesthetic copper components. More importantly, you can adopt design practices like dimensional checks, avoiding deep pockets with small radii, and reducing parts setups.
Set the Appropriate Feed Rate
The feed rate is the speed at which the cutting tool delivers precise cuts on the workpiece material. As a result, it would be best to set the appropriate feed rate before CNC machining copper parts. This is because it influences the CNC copper parts’ surface finishes, quality, and life span. Besides, using a high feed rate can result in extreme tool wear over time as copper heat quickly.
Select the Appropriate Tool Material
There are various grades of copper with varying solidity and machinability. Pure copper is a very soft metal, resulting in high chip formation and tool wear. A build-up edge can occur, causing poor surface finishing of CNC machined copper parts.
Therefore, choosing the suitable tool material for machining your copper parts is pivotal. Carbide or high-speed steel tools with sharp edges and shiny surfaces are ideal for CNC machining copper parts. More importantly, sharpen your cutting tools always before CNC machining copper.
Surface Finishing for Copper CNC Machined Parts
Surface finishes are post-processing treatments that enhance copper parts’ surface aesthetics and functionality. Here are some of the standard surface finishes suitable for copper parts:
Media Blasting
The media blasting surface finish technique helps to conceal the machining flaws or defects in copper CNC machined parts. This process offers a more subtle, duller, and durable finish.
Electroplating
Copper electroplating offers a protective layer on your copper machined parts’ external surface to prevent oxidation. It is effective in prolonging the lifespan of your copper parts. The electroplating process treats the metal plates without compromising their electrical and thermal conductivity.
Electropolishing
Electropolishing involves removing a microscopic material layer from the surface of the copper parts. The material removed often ranges from 0.00254mm to 0.0635mm in width. Consequentially, this strategy makes the surface of the copper CNC machined parts smoother and shiny. Electropolishing enhances the surface of machined copper parts, preventing them from corrosion.
Different Types of CNC Machining Methods for Copper
Although machinists and product engineers use extensive metal machining services to make different metal parts in various industries, some machining methods are only ideal for specific metals. However, you can cut copper alloys with varying forms of machining. Typical CNC machining methods for copper include:
CNC Milling
CNC milling is a computer-controlled method that automates the rotating cutting tools’ feed rate, machining speed, and movement when milling copper. The CNC milling copper process uses multi-point cutting tools that rotate and move across the copper workpiece’s surface. The tool makes consistent and precise cuts slowly till it forms the desired shape and size.
Machinists often use CNC mills to cut copper alloys, producing precise and intricate products due to their machinability properties. The 2-flute carbide end mill is the commonly used cutting tool for copper milling.
Moreover, product designers utilize the CNC copper milling process to create diverse design features for copper machined parts. Typical examples of these features include grooves, contours, notches, flat surfaces, holes, pockets, etc.
CNC Turning
The turning method requires holding the copper workpiece in a fixed position. As such, the cutting tools remain stationary as it approaches the workpiece. Consequently, the turning tool gradually reduces the copper material’s size to the desired dimension when it rotates at the programmed speed.
CNC turning is a cost-effective and highly adaptable machining technique. It allows rapid manufacturing of high-precision copper products. As a result, it is an ideal method for machining several mechanical and electrical equipment, including radiators, electrical wire connectors, bus bars, valves, etc.
CNC Machining Copper Applications
The different grades of coppers have extensive applications across industries ranging from consumer goods to transport, electrical, and construction. Even though copper is a versatile material, its compatible post-processing treatments help further to increase its resistance to corrosive elements and wear.
Typical applications of CNC machining copper include:
- Electrical connectors
- Heat exchangers
- Bearings and gears
- Gas welding nozzles
- Radiators
AT-Machining: Your Best Partner for Copper CNC Machining
This article has carefully discussed the copper CNC machining process. Now that you understand the different grades of copper CNC machining, machining methods for copper, and surface finishes for CNC machined copper parts, you should be able to determine the suitable copper material for your project. Choosing the right copper material that matches your product design and partnering with the ideal manufacturer with specialized process knowledge impacts the success of your manufacturing project.
AT-Machining is the ideal partner when you need the assistance of a reliable CNC copper machining services expert. We are a reliable copper CNC services provider with professional experience machining precise, superior-quality copper parts for innovative companies.
Our innovative machines and a team of skilled machinists and engineers allow us to offer customer-designed copper components. Contact us today; let’s handle your prototyping and copper parts manufacturing needs.
FAQs
What Is the Best Copper for CNC Machining?
The best copper for machining is 101 copper. It exhibits excellent conductivity as a result of its 99.9% purity. Generally, CNC machines can effectively fabricate this copper into desired shapes and sizes due to its impressive ductility. Engineers often use this metal in various applications as it is more cost-effective.
Is It Hard to Machine Copper?
You may find it difficult to machine copper in its pure form because of its high ductility and toughness. However, alloying copper with zinc, nickel, silicon, aluminum, or tin would be best. This changes the composition of the metal material. As a result, it becomes more machinable and allows machining to precise tolerances.
Can a CNC Machine Cut Copper Materials?
CNC machines make precise and accurate cuts on copper and its alloys to make copper products with excellent surface quality. As such, the copper CNC machining method offers high repeatability levels that help machine copper parts that meet stringent requirements and specifications easily.
Are Copper Materials Suitable for Machining?
Copper and its different alloys exhibit high corrosion resistance, making them well-suited for manufacturing various parts like industrial machinery and engines—additionally, the copper sulfate layer, which copper forms on its layer, offers further protection from corrosion.
