Smelting is the starting point of production for many copper and copper alloy products, and it often requires high purity copper cathode plates with copper content over 99.95%. The highest purity level for for commercial cathode plate will be over 99.99% with oxygen content less than 5PPM. The most popular oxygen-free copper (OFC) is a high-purity copper with minimal oxygen level normally less than 10PPM, and the high purity copper with low oxygen content is crucial for achieving high electrical conductivity and preventing hydrogen embrittlement in hollow conductors.
Melting of Copper Cathode
Important Factors for Making a Sound Copper Smelting for Hollow Conductors
Qualified melting for hollow conductors is critical for ensuring the quality and performance of hollow copper conductors, and Fabmann also focuses on following steps:
√ Material Selection
Choose the appropriate copper grade based on the desired properties of the hollow conductor. For high-conductivity applications, OFC is preferred. Always use high-purity copper cathodes to minimize impurities and ensure consistent composition throughout the melting process, and the copper cathodes shall always be checked before melting process starts.
√ Material Cleanliness
Make sure that the copper cathodes are free from contaminants like oxides, oils, and grease.
Copper Cathode Plates
√ Temperature Control
Precise temperature control is crucial to ensure that the copper melts completely and avoids overheating, which can lead to oxidation and loss of properties.
√ Melt Time
The melt time should be sufficient to allow for complete melting and homogenization of the copper.
√ Stirring Process
Making sure that stable stirring is conducted during melting process, so all chemical components are evenly spread in each melting production.
√ Degassing
Degassing is a crucial step in the melting process, and this technique is designed to improve the quality and properties of the final product. It involves removing dissolved gases, primarily hydrogen and oxygen, from the molten copper to prevent defects and enhance its performance. As you might be aware of that dissolved gases can lead to porosity, which weakens the material and reduces its electrical conductivity. Therefore degassing has following benefits:
1. Minimize porosity.
2. Minimize oxidation, and oxygen is a major contaminant in molten copper, leading to the formation of oxides that can affect the material's properties and electrical conductivity.
3. Improved surface quality, degassing contributes to a smoother and cleaner surface finish for the solidified copper, enhancing its aesthetic appeal and functionality.
4. Enhanced casting properties because degassing improves the fluidity of the molten copper, allowing for better filling of molds and producing castings with finer details and dimensional accuracy.
√ Chemical Composition Control:
Take samples of the molten copper for further analysis and testing to ensure it meets the required specifications. Composition analysis, and this important step to make sure that the molten copper meets the required purity level.
This shall be documented for each melt with full production configuration like melting temperature and melting duration.
Copper Ingot Casting Analysis
The molten copper can be then cast into various shapes like billets, rods and tubes, which are then used as the mother material for forming processes like extrusion, drawing, or seamless tubing which are widely used for hollow copper conductors.