6063 Aluminum Tempers Overview
Aluminum alloy 6063 is available in several commonly used temper conditions, allowing its mechanical and physical properties to be tailored for different applications. At GNEE, the most frequently supplied tempers for 6063 aluminum include:
Annealed (O temper): Fully softened wrought alloy
6063-T4: Solution heat treated and naturally aged
6063-T6: Solution heat treated and artificially aged
Each temper provides a different balance of strength, ductility, and processing performance, making 6063 aluminum highly versatile for architectural and industrial uses.
Physical Properties of 6063 Aluminum Alloy
6063 aluminum exhibits stable physical and thermal characteristics, which contribute to its popularity in construction and extrusion applications.
Typical Physical Properties of 6063 Aluminum
Melting Point: ~655 °C
Density: 2.70 g/cm³
Coefficient of Thermal Expansion: 23.5 × 10⁻⁶ /K
Modulus of Elasticity: ~69.5 GPa
Thermal Conductivity: ~201 W/m·K
Electrical Conductivity: ~52% IACS
Electrical Resistivity: ~0.033 × 10⁻⁶ Ω·m
These properties remain consistent across different tempers, making design calculations reliable and predictable.
Element Optimization in 6063-T5 Aluminum Profiles
For 6063-T5 aluminum profiles used in construction, achieving the required mechanical performance depends heavily on precise chemical composition control. When processing conditions are identical, higher magnesium and silicon content generally leads to increased yield strength and tensile strength.
In 6063 aluminum alloys, the primary strengthening phase is Mg₂Si.
Mg₂Si Strengthening Mechanism in 6063 Aluminum
The Mg₂Si phase consists of two magnesium atoms and one silicon atom, with relative atomic masses of 24.31 for magnesium and 28.09 for silicon. Based on this composition, the theoretical Mg:Si mass ratio in Mg₂Si is 1.73:1.
Mg:Si > 1.73: Excess magnesium remains after Mg₂Si formation
Mg:Si < 1.73: Excess silicon is present alongside Mg₂Si
Maintaining the correct balance is essential for optimal strengthening.
Influence of Magnesium and Silicon on 6063 Mechanical Properties
Excessive magnesium can negatively affect mechanical properties and increase production costs. In practice:
Magnesium content is typically controlled at around 0.5%
Total Mg₂Si content is maintained at approximately 0.79%
When the alloy contains 0.01% excess silicon, the tensile strength (σB) can reach about 218 MPa, exceeding standard performance requirements. Increasing excess silicon from 0.01% to 0.13% can raise σB to approximately 250 MPa, an improvement of about 14.6%.
Composition Control Strategy for 6063 Aluminum Alloy
To ensure sufficient Mg₂Si formation, it is necessary to account for silicon loss caused by impurities such as iron (Fe) and manganese (Mn). During actual alloy batching, GNEE carefully controls the composition to keep Mg:Si below 1.73, preventing excess magnesium from reducing the strengthening effect.
Recommended Composition Range for 6063 Aluminum
Magnesium (Mg): 0.45%–0.65%
Silicon (Si): 0.35%–0.50%
Mg:Si Ratio: 1.25 – 1.30
Iron (Fe): ≤ 0.10% – 0.25%
Manganese (Mn): ≤ 0.10%
This optimized balance ensures excellent mechanical performance, cost efficiency, and stable extrusion quality.
6063 Aluminum Phase Relationship (Al–Mg₂Si)
The pseudo-binary Al–Mg₂Si phase diagram at an Mg:Si weight ratio of 1.73:1 illustrates how the average solid composition shifts under non-equilibrium conditions typical of industrial solidification. This behavior explains the importance of precise element control in achieving consistent properties in 6063 aluminum products.
Summary from GNEE
Through controlled temper selection and precise magnesium–silicon optimization, 6063 aluminum alloy achieves an excellent balance of strength, extrudability, and surface quality. GNEE supplies high-quality 6063 aluminum products designed to meet demanding architectural and industrial standards.
