Copper and copper alloy is a manufacturing process that involves shaping copper & copper alloy into various cross sectional profiles by forcing it through a die. This production solution employs solely compressive, not tensile, forces, allowing for significant deformation of the copper without the risk of fracturing the material, and this versatile technique allows for the production of complex shapes with high precision and excellent surface finish, making it ideal for a wide range of applications.
What are the hot extrusion processes?
Extrusion is a complex production process that transforms raw copper billets into various shaped profiles. To achieve high quality extrusion including close tolerance, surface finish as well as mechanical properties, you need to follow a controlled steps. The following steps are essential:
1. Billet Preparation, it's always the very first step. It starts from casting molten copper into cylindrical billets of the desired diameter. The casting process ensures a homogeneous microstructure and uniform composition within the billet. After casting, the cast billets may undergo homogenization treatment to eliminate any microstructural inconsistencies and improve the overall uniformity of the material. Next step is to scalp billet surface for removing surface imperfections or impurities that could affect the extrusion process. Once above steps are finished, the billet is preheated to a specific temperature, typically between 700°C and 900°C, depending on the copper alloy and desired extrusion parameters. It's worthwhile to know that preheating enhances the ductility of the copper, making it easier to deform during extrusion.
2. Extrusion, extrusion has few processes. The first step is to lubricate the billet to reduce friction between the billet and the extrusion die. The lubricant also helps to prevent surface defects and improve the flow of the copper through the die. Loading and pushing by a hydraulic press, the billet will go through a the die, and the pressure required for extrusion depends on the cross-sectional area of the profile, the copper alloy, and the extrusion temperature. Once the copper goes through the die, the desired cross-sectional profile will be formed.
3. Cooling and Finishing, the extruded profile such as copper busbar is put onto a run-out table, where it is cooled by air. It is critical to achieve a rapid cooling because this process can prevent recrystallization and maintain the desired microstructure.
4. Straightening, the extruded profile may be straightened if necessary to remove any curvature or distortion caused during the extrusion process.
5. The extruded profile is cut to the desired length.
Extruded Copper Tube
How to do quality control for copper & copper alloy extrusion?
Quality control of copper extrusion involves a series of inspections and tests throughout the extrusion process, from raw material to finished product. Fabmann has accumulated rich experiences, and below is the summary:
1. Incoming Material Inspection, the QC always starts from raw material analysis which is chemical composition check. Verifying the chemical composition is the foundation to ensure that the raw material meets the specified alloy requirements. Spectrographic analysis or other analytical techniques can be used for this purpose. Examine the microstructure of the billets to ensure they are free from defects or inclusions that could affect the extrusion process and final product quality, and spectrometer is commonly used for microstructure evaluation. Of course, dimensional inspection is very basic control.
2. Temperature Monitoring, control of preheating temperature of the billet preheating temperature and the extrusion temperature is important to secure the desired properties.
3. Extrusion Pressure, control the extrusion pressure to ensure that it is sufficient to achieve the desired deformation without causing defects or excessive force on the equipment.
4. Extrusion Speed, Monitor and control the extrusion speed to ensure it is optimized for the specific profile and alloy to achieve the desired surface finish and dimensional accuracy.
5. Lubrication, lubrication is applied evenly and consistently to minimize friction and prevent surface defects.
6. Visual Inspection, regular extrusion process inspection on visible defects, such as surface cracks, scratches, or dimensional inconsistencies.
7. Dimension, measure the dimensions of the extruded profiles at regular intervals to ensure they meet the specified tolerances.
8. Straightness & Twist Inspection
9. Mechanical Property, depending on the application, conduct mechanical tests to determine the strength, hardness, and other relevant properties of the extruded profiles.
10. Non-Destructive Testing (NDT), employ NDT techniques, such as ultrasonic testing or eddy current testing, to detect internal defects or inconsistencies that may not be visible on the surface.
11. Traceability, maintain detailed records of all quality control inspections and tests, including the results and any corrective actions taken. Implement a system for traceability to track the materials and processes used for each batch of extruded profiles.
In conclusion, copper extrusion is a complex and multi-step process that requires careful control and expertise to produce high-quality products. By understanding the complete extrusion process, we can help you to optimize the operations and ensure that the extruded copper profiles meet the required specifications for various industrial and consumer applications. Fabmann implements a robust quality control program is essential for copper and copper alloy extrusion to ensure product quality, consistency, and customer satisfaction. By following these guidelines and continuously improving quality control practices, we can produce high-quality extruded copper products to meet your demands for various industrial and consumer applications.
How many types of Copper Extrusions?
Extrusion is a compressive forming manufacturing process that creates lengths of shaped cross-sections from metal billets. The process utilizes high force to squeeze the material through a shaped die and achieve the final desired shape and size. The die is made with a material with wear resistance and higher hot strength to ensure precise cross-sections and a smooth surface. Extrusion has been a preferred production solution due to its manufacturing speed, relatively low cost, and resulting smooth finishes. There are different extrusion solutions available depending on the material to be extruded and its application, and they are:
√ Direct extrusion, the most common process, the billet slides against walls of a heated container to be extruded through the die. The frictional forces at the container wall exert significant force back on the ram, and this frictional work is typically on the same order of magnitude as the work needed to reduce the cross-section of the billet.
√ Indirect extrusion, the die is instead pushed into the container holding the billet, providing a more uniform flow that results in more consistent diameters and microstructures. Indirect extrusion results in less frictional loss and is therefore a faster process that is easier on equipment.
√ Hydrostatic extrusion, it uses a hydraulic press to push a billet of metal through a die, forming it into the desired shape. This method is particularly well-suited for extruding copper due to its high ductility and ability to withstand high pressures.
√ Hot extrusions are done above the recrystallization temperature of the metal to be formed helping to prevent work hardening during the process and allowing large changes in shape. Hot copper extrusions are normally done between 600 and 1000˚C. Using temperatures above the dynamic recrystallization temperature results in a uniform fine grain structure in the final extrusion product.
√ Cold Extrusion, it is a metal forming process that involves shaping a copper billet at room temperature by forcing it through a die using a high-pressure press. This method utilizes the high ductility and work-hardening properties of copper to achieve precise shapes and improved mechanical strength.
√ Impact Extrusion, it is a high-speed metal forming process that utilizes a high-velocity impact to force a metal billet through a die, shaping it into the desired form. This method is particularly well-suited for producing small, intricate parts with high detail and dimensional accuracy.
Although extrusion can be extremely efficient for certain cross-sectional shapes, there are limits to its efficiency. The cross-sectional area of the part exceeds above 3 square inches, the extruded profile tends to curve slightly when it comes out of the die. Plus it is difficult to straighten by cold drawing, and therefore asymmetrical parts also tend to be difficult to make for the same reason.
What are the advantages of copper extrusion?
√ Precise and Complex Shapes, it can produce intricate profiles with tight tolerances, making it suitable for applications requiring high precision.
√ Good Surface Finish, it can result in smooth, consistent surface finishes, reducing the need for further polishing or finishing steps.
√ High Production Rates, it is a high-volume process, allowing for the efficient production of large quantities of copper profiles.
√ Material Efficiency, this process minimizes material waste, making it an environmentally friendly option.
√ Versatility, copper extrusion can be used with various copper alloys, offering a wide range of properties to meet specific application requirements.
√ Economy, considering the simplicity of the extrusion process, which also entails minimal use of resources, the cost of each pound of extrusion is so much lower than that of cast metals.
Even with all of these benefits, it is still important to note that extrusion's success will still depend on the quality of copper and copper alloy to be extruded. It is always mandatory to use superior quality copper material to produce durable and resilient extrusions.
What are the applications for extruded copper & copper alloy products?
Due to the versatility of copper extrusion, the production of extrusion is widely used for various industries including:
Extruded copper and copper alloys find extensive applications in various industrial sectors due to their unique combination of properties, including:
√ Electrical Industry, extruded copper bars and tubes such as busbars and conductors in power generation, transmission, and distribution systems due to their high electrical conductivity and ability to handle large currents.
Extruded copper windings are used in transformers and motors due to their high electrical conductivity and ability to withstand high temperatures.
√ Automotive Industry, extruded copper tubes are used in radiators and heat exchangers due to their excellent thermal conductivity and ability to withstand high temperatures and pressures.
√ Aerospace Industry, extruded copper tubes are used in heat exchangers for aircraft engines and environmental control systems due to their excellent thermal conductivity and ability to withstand extreme temperatures.
√ Chemical and Petrochemical Industry, extruded copper products such as valves and fittings, extruded copper tubes are used in heat exchangers for chemical processes due to their excellent thermal conductivity and ability to withstand corrosive fluids. Extruded nickel alloys tubes are used for piping and tubing in chemical and petrochemical plants due to their high corrosion resistance and ability to withstand high temperatures and pressures.
√ Marine Industry, the extruded nickel copper piping and components are widely used in shipbuilding due to their high corrosion resistance and ability to withstand marine environments.
√ Offshore Oil and Gas
Extruded copper and copper alloys play a vital role in various industrial applications due to their unique combination of properties. Their high electrical and thermal conductivity, corrosion resistance, strength, and ductility make them essential materials for power generation, electronics, automotive, aerospace, chemical, and marine industries. Our team focus process control, and our quality control consistently covers following perspectives:
√ Tensile
√ Emission Spectrometer
√ Rockwell Hardness
√ Conductivity
√ Resistivity
√ Hydrogen Embrittlement
√ Oxygen PPM Analysis
√ Atomic Absorption Spectrometer Testing
√ Grain Size Evaluation
By leveraging the advantages of extruded copper and copper alloys, Fabmann can help you to achieve improved performance, efficiency, and innovation in your operations.
