2026-01-19
🏭 What is a Billet? The Solidified Recipe
A billet is a solid, cylindrical bar of aluminum alloy, typically 6 to 9 meters in length, with a diameter ranging from 100mm to over 300mm. It is created through a process called **Direct Chill (DC) Casting**:
1. **Melting & Alloying:** Precisely weighed amounts of primary aluminum and alloying elements (Mg, Si, etc.) are melted in a large furnace to create the specific chemical composition, such as **6063 or 6061**.
2. **Refining & Degassing:** The molten metal is treated to remove hydrogen gas and non-metallic impurities, ensuring internal soundness.
3. **Casting:** The clean, liquid alloy is poured into a vertical mold. As it exits the mold, it is immediately cooled by water jets, solidifying into a continuous cylindrical bar.
🔬 Why Billet Quality is Non-Negotiable
The internal structure and purity of the billet directly dictate the extrudability and final properties of the profile. Key quality parameters include:
* **Chemical Composition Uniformity:** The alloying elements must be evenly distributed. Any segregation can lead to inconsistent strength, anodizing color variations, or surface defects in the final profile.
* **Grain Structure:** A fine, equiaxed grain structure is essential. A coarse or columnar grain structure can lead to poor surface finish, reduced mechanical properties, and cracking during extrusion.
* **Low Hydrogen & Inclusion Content:** Trapped gas or solid impurities (oxides, carbides) become internal defects. Under the immense pressure of extrusion, these can surface as **blisters, streaks, or tearing**, ruining the profile's surface and integrity.
⚙️ The FONIRTE Standard: From Raw Material to Reliable Input
We do not accept billets as a commodity. We specify and verify them as a critical engineering input.
* **Strategic Sourcing:** We partner with top-tier aluminum mills that employ advanced casting technology and have robust quality management systems (e.g., compliant with **ISO 9001** and **IATF 16949** for automotive-grade material).
* **Homogenization – The Critical Pre-Process:** Before extrusion, **FONIRTE** billets undergo a mandatory **homogenization heat treatment**. They are heated to a high temperature (~500-580°C) and held for several hours. This process:
* **Dissolves harmful phases** that could cause extrusion defects.
* **Equalizes the chemical composition** throughout the billet.
* **Relieves internal casting stresses.**
This results in a billet with optimal softness, uniformity, and extrudability.
* **Incoming Inspection:** We perform **spectrochemical analysis** to verify composition and may conduct ultrasonic testing to check for internal flaws on critical orders.
**In Essence:** The aluminum billet is the **unsung hero of extrusion quality**. A perfect die and a powerful press cannot compensate for a poor-quality billet. By rigorously controlling the chemistry, structure, and pre-treatment of our billets, **FONIRTE** ensures that the very foundation of our extrusion process is solid. This upstream diligence is what allows us to consistently deliver profiles with **superior surface finish, dimensional accuracy, and mechanical reliability**—qualities that are literally cast in metal from the very beginning.
*Quality is cast, then extruded. It starts with the billet.* ⚙️🧱➡️🏗️