Usinage du cuivre : Conception, usinage, finition et autres conseils

Copper, a versatile metal, is prized for its beautiful finish and useful applications, from art to cookware. It also offers excellent material and electrical properties, making it valuable for engineering intricate components like EDM electrodes. However, copper machining can be challenging due to its toughness. To make it more workable, copper is often mixed with metals like aluminum, zinc, silicon, and tin to create alloys like brass, bronze, and nickel-silver, each suited for specific machining tasks.

This article will explore copper machining techniques, important considerations, diverse applications, and essential machining services. Join us as we simplify the world of copper machining, empowering you with the knowledge to work effectively with this versatile metal.

Key Considerations for Copper CNC Machining

Machining copper involves carefully considering several factors, including cutting techniques, part design, tool selection, and machining conditions. These elements are interconnected and require optimization to achieve desired outcomes.

Optimizing Part Design

Copper is a valuable material, and its cost can vary significantly based on size and application. To maximize efficiency and minimize costs, strategically designing copper parts is essential. Consider copper’s advantages, such as thermal conductivity and specific heat capacity, when deciding where to incorporate it.

Copper is often used in heat exchangers, laser components, and electrical systems. Efficient design is crucial for parts with holes or those that require turning to minimize material wastage.

Choosing the Right Grade of Copper

The appropriate copper grade is critical, depending on the part’s intended use. Common grades include Copper 101 and Copper 110. Copper 101 is purer but less machinable than Copper 110.

Copper 110 offers better machinability and electrical conductivity, making it suitable for applications like busbars. Additionally, manufacturers reserve copper 101 for critical parts that require maximum efficiency. Consider the elasticity of the chosen grade, especially for turning jobs.

Working with Copper

Copper precision machining depends on various parameters, including cutting tools, speed, coolant, and feed rate.

• Cutting Tools: High-speed steels (HSS) and cemented carbides are commonly used cutting tools for copper machining. These are wear-resistant, hard, and tough, improving tool life and smooth machining.
• Cutting Speed: Cutting speed is a crucial factor affecting tool life. Adjust cutting speed based on the tool material, with carbide tools typically requiring a slightly lower speed.
• Cutting Fluid: The use of cutting fluid in copper machining depends on the job’s requirements for cooling and lubrication. Emulsified oils work well for cooling, while low-viscosity oil is ideal for lubrication.
• Vitesse d'alimentation : Carefully control the feed rate to avoid excessive temperature rise at the tool and workpiece interface, which can result in a poor surface finish.

Post-Processing Copper Parts

Post-processing techniques can enhance the surface finish and properties of copper parts. Common methods include anodizing, electropolishing, and electroplating. These copper machining processes help improve corrosion and chemical resistance by applying a protective coating to the copper part’s surface.

Common Copper Machining Techniques

Machining copper presents unique challenges due to its high flexibility, plasticity, and toughness. However, alloying copper with zinc, tin, aluminum, silicon, and nickel significantly enhances its machinability. These copper alloys often require less cutting force than other materials of similar strength. Having said that, below are some common copper machining processes that are considered by professionals offering copper machining services to ensure precision production:

CNC Milling for Copper

You can efficiently machine copper alloys with various methods, including CNC copper milling. This automated process employs computerized controls to manage multi-point rotary cutting tools. As these tools rotate and traverse the workpiece’s surface, they gradually shape it to the desired specifications. CNC  copper milling is versatile, allowing the creation of grooves, contours, notches, holes, pockets, slots, and flat surfaces.

Here are key considerations for copper milling copper or its alloys:

• Utilize common cutting materials like carbide application groups (N10 and N20) or HSS grades.
• Increase tool life by reducing cutting speed by 10%.
• When machining a copper cast alloy with a cast skin, decrease cutting speed by 15% for carbide tools or 20% for HSS grade tools.

CNC Turning for Copper

CNC turning is another effective method for machining copper, where the tool remains stationary while the workpiece moves to achieve the desired shape. This adaptable approach is commonly used to create electronic and mechanical components.

When working with copper, please pay close attention to speed due to its excellent thermal conductivity, which can lead to increased tool wear over time. Consider the following tips for CNC-turning copper or copper alloys:

• Set the cutting tool edge angle between 70° and 95°.
• For softer types of copper that can easily smear, choose a cutting tool with an edge angle close to 90˚.
• Maintain a constant cutting depth and reduce the cutting tool edge angle to minimize tool stress, prolong tool life, and increase cutting speed.
• Making the angle between the main and smaller cutting edges bigger helps the tool manage more force and lowers heat stress.

Design Considerations for Copper Precision Machining

Creating designs with copper-machined parts requires careful consideration of several key factors. Copper, known for its unique properties, should be used judiciously in designs due to its cost. Leveraging copper for its exceptional properties can be achieved by incorporating it strategically into your designs.

Choosing Copper for Specific Reasons

Having specific reasons is essential when opting for copper or copper alloy parts. Copper offers high corrosion resistance, excellent electrical and thermal conductivity, ease of soldering, high ductility, and machinability when alloyed. Incorporating copper into your design should align with maximizing these benefits.

Selecting the Appropriate Material Grade

During the design phase, selecting the right grade of copper is crucial for your application. Using pure copper (C101), with its 99.99% copper purity, can be challenging and costly for mechanical parts.

In contrast, C110, while still providing good conductivity, is generally easier to machine and more cost-effective. The choice of material grade should align with the critical properties required for your design’s function.

Designing for Manufacturability

Design for Manufacturability (DFM) principles should always guide your design process, regardless of the material used. Fictiv recommends optimizing tolerances while retaining necessary functionality, minimizing dimension inspections, avoiding deep pockets with small radii, and limiting part setups. When designing copper parts, keep these best practices in mind:

• Maintain a minimum wall thickness of 0.5 mm.
• For CNC milling, think about using parts up to 1200 x 500 x 152 mm in size, and for CNC turning, parts up to 152 x 394 mm.
• For undercuts, we suggest square profiles, full-radius, or dovetail profiles.

Finishing Guidelines for Copper Machined Products

Lorsqu'il s'agit de copper CNC machining, achieving the desired finish is critical. There are various considerations to keep in mind to ensure your copper parts meet your surface finish requirements effectively.

Optimizing Copper CNC Machining Parameters

Surface finish control begins within the copper machining processes themselves. Certain copper machining techniques can be adjusted to influence the surface quality of the machined parts. One key factor to focus on is the nose or tool corner radius.

The nose radius is pivotal in determining finish quality for softer and pure copper alloys. Minimizing the nose radius is essential, not only to prevent smearing of softer metals but also to reduce surface roughness.

A smaller nose radius produces a higher-quality cut surface by minimizing feed marks. In this context, wiper inserts are preferable to traditional nose radius tools, as they enhance the surface finish without altering the feed rate.

Post-Processing Options for Finish

Besides improving cuivre cutting techniques, you can also use finishing methods afterward to get the look you want.

• Hand Polishing: While labor-intensive, hand polishing can produce an aesthetically pleasing surface shine.
• Media Blasting: This technique creates a uniform matte finish and effectively conceals minor flaws in the surface.
• Electropolishing: Particularly well-suited for copper due to its exceptional electrical conductivity, electropolishing brightens and enhances the appearance of copper parts. It is an excellent choice for achieving a refined finish.

Applications of Machined Copper Parts

Copper cutting offers many opportunities in different areas because of its special features and flexibility. Let’s explore some key areas where machined copper parts shine:

1. Mechanical Applications

Copper’s exceptional thermal conductivity and high resistance to corrosion make it an invaluable choice for mechanical components. In this domain, you’ll find copper put to excellent use in crafting:

• Heat Exchangers: Copper’s heat conductivity is key to efficiently transferring thermal energy.
• Radiators: Copper’s durability and heat dissipation properties make it a prime candidate for radiator construction.
• Paliers: Copper’s anti-friction qualities and resistance to wear contribute to the longevity of bearings.
• Gas Welding Nozzles: Precision-machined copper nozzles play a vital role in welding processes.
• Plumbing Components: Copper’s resistance to corrosion makes it a trusted material for plumbing fixtures.

2. Electrical and Electronics

Copper’s stellar electrical conductivity opens the door to many applications in the electrical and electronics realm. Here, machined copper finds its way into:

• Bus Bars: Copper’s conductivity makes it an ideal choice for bus bars, facilitating the efficient flow of electrical current.
• Electrical Components: Connectors, windings, and terminals benefit from copper’s electrical prowess.
• General Wiring: Due to its reliability, copper wiring is a staple in countless electrical installations.

3. Diverse Industrial Uses

Beyond its thermal and electrical attributes, copper’s non-magnetic nature and versatility find application in various industrial sectors, proving its worth in:

• Fabrication: Copper machining solutions are crucial in producing precise components for diverse industries.
• Aérospatiale: Copper’s reliability extends to aerospace applications, where precision and performance are paramount.
• Automobile: From electrical systems to engine components, machined copper plays a role in enhancing automotive performance.
• Renewable Energy: Copper is used in green energy solutions like solar panels and wind turbines because it conducts electricity well.

Conclusion

In conclusion, as you delve into copper machining solutions encompassing design, precision machining, and finishing of copper machining processes, you must explore the full spectrum of mechanical and chemical finishing options. This comprehensive evaluation will help you achieve the desired quality and functionality of your copper-machined components.

Furthermore, selecting a proficient CNC copper machining services of professionals like Prototool ensures your parts are impeccably machined and delivered punctually, aligning precisely with your specifications. This synergy of meticulous craftsmanship and reliable expertise is the key to success in copper CNC machining.