Annealing Process of Aluminum 6063
During the production of civilian aluminum extruded profiles, 6063 aluminum alloy typically undergoes high-temperature homogenization annealing. At GNEE, the standard homogenization temperature for 6063 alloy ingots is controlled at 560 ± 20°C, with a soaking time of 4–6 hours. Cooling is carried out either by forced air cooling outside the furnace or by rapid water spraying.
Homogenization treatment significantly improves extrusion performance. Compared with non-homogenized ingots, homogenized 6063 ingots can achieve:
6%–10% lower extrusion force
Higher extrusion speed
Improved surface quality
Effect of Homogenization Cooling on 6063 Aluminum Microstructure
The cooling rate after homogenization has a decisive influence on precipitation behavior. When ingots are rapidly cooled after uniform heating:
Mg₂Si dissolves almost completely into the aluminum matrix
Excess silicon dissolves or remains as finely dispersed precipitates
Such ingots can be extruded at lower temperatures while still achieving excellent mechanical properties and a bright surface finish, which is ideal for architectural and industrial profiles.
Energy-Saving Heating Technology for 6063 Aluminum Extrusion
Replacing traditional resistance-heating furnaces with fuel- or gas-fired heating furnaces can significantly reduce energy consumption in aluminum extrusion production.
With proper selection of:
Furnace type
Burner system
Air circulation mode
Uniform and stable heating can be achieved, helping to stabilize the extrusion process and improve product consistency.
After years of optimization, modern combustion-type ingot heating furnaces with over 40% combustion efficiency have been widely adopted. In these systems, 6063 ingots are rapidly heated to above 570°C, soaked briefly, and then cooled in the discharge zone to near extrusion temperature before extrusion.
This process is referred to as semi-homogenization treatment, which fully satisfies the hot extrusion requirements of 6063 aluminum alloy. It eliminates the need for a separate homogenization process, reduces equipment investment, and lowers energy consumption, making it highly cost-effective and suitable for large-scale promotion.
Heat Treatment and Extrusion of Aluminum 6063
1. Ingot Heating for 6063 Aluminum
In aluminum extrusion, temperature control is the most critical factor affecting:
Product quality
Production efficiency
Energy consumption
Die life
For 6063 aluminum, it is essential to prevent premature precipitation of soluble phases during heating and extrusion.
Heating temperature is generally set within the Mg₂Si precipitation range
Rapid heating helps reduce Mg₂Si precipitation time
Typical heating temperatures:
Non-uniform ingots: 460–520 °C
Uniformly cast ingots: 430–480 °C
As extrusion progresses, the temperature in the deformation zone gradually increases. To avoid extrusion cracking, the extrusion speed should be gradually reduced as temperature rises. Final extrusion temperature is adjusted according to profile design and unit pressure.
2. Extrusion Speed Control for 6063 Profiles
Extrusion speed has a direct impact on:
Deformation heat
Metal flow uniformity
Recrystallization and solid solution behavior
Mechanical properties
Surface quality
If extrusion speed is too high, surface defects such as cracks, pitting, and uneven deformation may occur.
For 6063 aluminum profiles, the recommended metal flow rate is typically 20–100 m/min, depending on profile geometry and size.
Modern extrusion lines use programmed and simulated speed control, as well as advanced technologies such as
Isothermal extrusion
CADEX extrusion systems
These technologies automatically adjust extrusion speed to maintain a stable deformation-zone temperature, allowing high-speed extrusion without cracking.
Advanced Cooling and Speed Enhancement Techniques
Several process improvements are used to increase extrusion efficiency:
Induction heating orientation to balance deformation heat
Water-cooled dies, increasing extrusion speed by 30%–50%
Nitrogen or liquid nitrogen–cooled dies, which:
Increase extrusion speed
Extend die life
Improve surface quality
Nitrogen cooling reduces oxidation and aluminum oxide adhesion at the die exit, resulting in cleaner and smoother profiles.
3. Quenching Process of 6063-T5 Aluminum
6063-T5 quenching is designed to retain Mg₂Si in solid solution after extrusion. Once the profile exits the die, it is rapidly cooled to room temperature.
Key points:
Cooling rate directly affects strengthening phase content
Minimum cooling rate for 6063 alloy: 38 °C/min
Air cooling is sufficient for quenching
By adjusting fan configuration and speed, the profile temperature can be reduced to below 60°C before tension straightening.
4. Tension Straightening of 6063 Aluminum Profiles
After extrusion, profiles are pulled by a traction machine, which applies controlled tension synchronized with the extrusion speed.
Tension straightening:
Eliminates bending, twisting, and uneven lengths
Reduces residual stress
Improves mechanical performance
Ensures stable surface quality
This step is especially important for multi-line extrusion and precision architectural profiles.
5. Artificial Aging Efficiency of 6063 Aluminum
Artificial aging requires strict temperature uniformity, with an allowable variation of ±3–5°C.
For 6063 aluminum alloy, typical aging parameters are:
Temperature: ~200 °C
Time: 1–2 hours
To further enhance mechanical strength, some producers age at 180–190°C for 3–4 hours, though this reduces production efficiency.
Summary: Annealing and Extrusion of 6063 Aluminum at GNEE
Through optimized homogenization annealing, precise temperature control, advanced extrusion speed management, and efficient quenching and aging, 6063 aluminum alloy achieves excellent extrusion performance, mechanical properties, and surface finish.
At GNEE, we apply advanced heat treatment and extrusion technologies to supply high-quality 6063 aluminum profiles for architectural, industrial, and precision applications worldwide.
