T5 vs T6 Tempering: Heat Treatment & Mechanical Hardness in Solar Extrusions
Understanding the critical differences between air-cooled T5 and solution-heat-treated artificial precipitation-aged T6 tempers in solar aluminum structures.
Key Engineering Takeaways
- ✓ T6 temper delivers 40% higher mechanical yield strength compared to T5
- ✓ Webster hardness must reach min. 12 HW across every production batch
- ✓ Prevents catastrophic fastener pull-out and flange bending under storm winds
Extrusion Quenching & Artificial Aging Kinetics
When aluminum exits the extrusion press at 500°C, it must be rapidly cooled to hold alloying elements in solid solution. T5 profiles are cooled from elevated temperature shaping and artificially aged. T6 profiles undergo rapid water/forced-air quench followed by 6 to 8 hours in artificial aging precipitation furnaces at 180°C–200°C, nucleating fine Mg2Si needles that block dislocation movement.
Hardness & Yield Strength Benchmarks
T5 temper typically yields 8–10 Webster Hardness (HW) and ~130 MPa yield strength, which is inadequate for gusting wind uplifts. T6 temper guarantees minimum 12–14 HW (approx. 75–85 HB) and yield strength exceeding 200–240 MPa, satisfying Eurocode 9 structural requirements.
Frequently Asked Technical Questions
Why is T5 unsuitable for heavy solar racking?
How is hardness verified during manufacturing?
Require Project Statics Calculation?
Our engineering desk calculates project-specific wind uplift and snow load moment capacities according to Eurocode 9 within 24 hours.