Copper Rod Forging:From Material Selection to Precision Processing

Material selection: Select appropriate copper rod materials (e.g., pure copper (T2), phosphorus-deoxidized copper (TP2)) based on the product's final application requirements, such as conductivity, corrosion resistance, or decorative properties.

1. Cutting: Use cutting equipment to slice long copper rods into blanks of required dimensions for forging.

Step 2: Heating

1. Loading into furnace: Place the copper rod billet into the heating furnace (e.g., box furnace or induction furnace).
2. Temperature control: Heat the copper rod to a specific "forging temperature". For pure copper, this temperature range is typically between 750°C and 900°C. At this temperature, the copper exhibits a bright orange-red color.

• Temperature is too low: poor plasticity, easy to crack.
• Excessive temperature: It is easy to produce "overburning" phenomenon, which leads to coarse grains, grain boundary oxidation and material scrap.

Step 3: Forging and forming (the core process)

This is the process of heating the copper rod blank and shaping it into the target shape by external force.

1. Primary forging (drawing or upsetting):

• Drawing: An increase in the length of a copper rod with a decrease in its cross-sectional area achieved by hammering. It is commonly used for manufacturing shafts and rod-shaped components.
• Brazing: A process where copper bars are hammered to reduce their length and increase their cross-sectional area. It is commonly used for manufacturing disc-shaped components such as flanges and gears.

1. Forming and Forging: Craftsmen use various tools such as mallets, hammers, flat hammers, and shaping hammers to perform precise shaping on an anvil. This process may include:

• Bending: Forging a copper rod into the desired curvature or angle.
• Twist: Rotate one part of a copper rod relative to the other.
• Punching: Creating holes in red-hot copper.

· Key Points:

• Strike while the iron is hot: Forging must be performed continuously and rapidly while the copper is hot. Once the temperature drops below the recrystallization temperature (approximately 500°C), the material must be reheated in the furnace.
• Multiple heat treatments: Complex workpieces typically require repeated cycles of heating, forging, and reheating to achieve the desired properties.

Step 4: Cool down

After forging, the cooling method of the workpiece has a direct effect on its final properties.

• Air cooling: Natural cooling in air. This is the most commonly used method, resulting in more uniform tissue distribution.
• Water cooling/quenching: For certain copper alloys with specific requirements, rapid cooling may be employed to achieve particular properties, though pure copper rarely utilizes this method.

Step 5: Subsequent Processing and Finishing

Forging is only the forming of the blank, to become a qualified product, it also needs a series of follow-up processing.

1. Heat treatment (annealing): After forging, the copper material has work hardening and residual stress. Through annealing treatment, the grain size can be refined, plasticity can be restored, and stress can be eliminated.
2. Cleaning: Remove the oxide scale (copper slag) and oil contamination from the forging surface.
3. Correction: Corrects minor deformations that may occur during the cooling process.
4. Mechanical finishing:

• Cutting: Remove excess material and flash to achieve precise dimensions.
• Welding: For complex structures, multiple forged components may need to be professionally welded together.
• Polishing: Enhances surface smoothness to meet decorative or functional requirements.
• Drilling/Drilling: Create holes and threads for installation.