6055 Aluminum alloy,Aluminum 6055 alloy,E FORU

### **6055 Aluminum Alloy: Product Introduction** **Overview** 6055 aluminum alloy is a modern, heat-treatable Al-Mg-Si-Cu alloy specifically designed to offer an excellent combination of **high strength, good formability, and superior surface finish**. It was developed primarily for automotive body sheet applications where these properties are critical. The alloy can be heat-treated to various tempers (such as T4, T6, T78, T81) to achieve a wide range of property combinations, making it highly versatile for demanding structural and cosmetic applications. --- #### **1. Chemical Composition (Weight %)** The chemical composition is carefully balanced to optimize strength, formability, and brazeability. | Element | Typical / Target (%) | Notes | | :--- | :--- | :--- | | Silicon (Si) | 0.8 - 1.2 | Primary alloying element for strength via Mg₂Si precipitation. | | Iron (Fe) | ≤ 0.20 | Impurity, controlled to maintain formability. | | Copper (Cu) | 0.10 - 0.25 | Enhances strength and age-hardening response. | | Manganese (Mn) | 0.10 - 0.20 | Controls grain structure and improves strength. | | Magnesium (Mg) | 0.50 - 0.9 | Primary alloying element for strength via Mg₂Si precipitation. | | Chromium (Cr) | ≤ 0.10 | Impurity, typically kept low. | | Zinc (Zn) | ≤ 0.10 | Impurity. | | Titanium (Ti) | ≤ 0.10 | Used as a grain refiner. | | Other (Each) | ≤ 0.05 | - | | Other (Total) | ≤ 0.15 | - | | **Aluminum (Al)** | **Balance** | | --- #### **2. Physical Properties** The physical properties are characteristic of the 6xxx series aluminum alloys. | Property | Typical Metric Value | | :--- | :--- | | **Density** | 2.70 g/cm³ | | **Melting Range** | ~ 555 - 650 °C | | **Electrical Conductivity** | ~ 50-55% IACS (T4 temper); decreases in higher strength tempers (T6). | | **Thermal Conductivity** | ~ 170 - 190 W/m·K | | **Coefficient of Thermal Expansion (20-100°C)** | 23.4 x 10⁻⁶ /°C | --- #### **3. Mechanical Properties (Typical by Temper)** The mechanical properties of 6055 are highly dependent on the temper. Key tempers include: * **T4 Temper (Solution Heat-Treated and Naturally Aged):** Characterized by high formability. * **Tensile Strength:** ~ 240 - 280 MPa * **Yield Strength (0.2% Offset):** ~ 120 - 150 MPa * **Elongation:** ~ 22 - 28% * **T6 Temper (Solution Heat-Treated and Artificially Aged):** Provides maximum strength. * **Tensile Strength:** ~ 320 - 360 MPa * **Yield Strength (0.2% Offset):** ~ 300 - 340 MPa * **Elongation:** ~ 10 - 14% * **T78 / T81 Temper (Paint-Bake Temper):** Specifically optimized for automotive applications. The material is formed in T4 state and then gains strength during the paint-curing (bake) cycle, achieving a final strength level between T4 and T6. * **Tensile Strength (after bake):** ~ 290 - 330 MPa * **Yield Strength (after bake):** ~ 250 - 290 MPa --- #### **4. International Standards** 6055 aluminum alloy is recognized in several major international standards, particularly in the automotive sector. * **ASTM (USA):** * **ASTM B209:** Standard Specification for Aluminum and Aluminum-Alloy Sheet and Plate. * **AA (Aluminum Association, USA):** The Aluminum Association officially registers alloy 6055. * **EN (European Standards):** * **EN 485-2:** Specification for chemical composition of wrought aluminum and aluminum alloys. * **EN 573-3:** Specification for mechanical properties of wrought aluminum and aluminum alloys. * **GB (Chinese Standard):** **GB/T 3190** (Wrought Aluminum and Aluminum Alloy Chemical Composition). * **JIS (Japanese Industrial Standards):** May be covered under general A6XXX series classifications. --- #### **5. Product Applications** 6055 is predominantly used in applications requiring a superior surface quality combined with high strength. * **Automotive Body Panels:** The primary application. It is extensively used for: * **Outer Panels:** Doors, hoods, fenders, and liftgates where a Class-A surface finish is critical. * **Inner Structural Panels:** Body-in-white components like reinforcements and brackets. * **Transportation:** For body panels and structural parts in buses, trains, and trailers. * **Architectural Applications:** Where a high-strength, anodizable alloy with a good finish is required. * **Consumer Durables:** For high-end appliances and electronics casings. --- #### **6. Key Characteristics & Advantages** * **High Strength after Paint Bake:** Its key advantage is the significant increase in yield strength (bake-hardening response) during the automotive paint-curing oven cycle, leading to excellent dent resistance in final body panels. * **Excellent Formability:** In the T4 temper, it has high ductility, allowing for complex stamping and forming operations. * **Superior Surface Quality:** It is known for producing an excellent surface finish after painting, which is essential for automotive Class-A surfaces. * **Good Corrosion Resistance:** Inherits the good general corrosion resistance of Al-Mg-Si alloys. * **Good Hemming Performance:** Its mechanical properties allow for clean and crack-free hemming operations, which is crucial for assembling automotive doors and hoods. * **Good Weldability:** It is readily weldable using common techniques like Resistance Spot Welding (RSW) and Metal Inert Gas (MIG) welding. **Disclaimer:** The information provided is typical and for reference purposes. Actual properties can vary based on product form (sheet thickness), specific temper, processing history, and the manufacturer. For critical design and procurement, always consult the manufacturer's certified datasheet and the relevant material standards.

Packing of Standard Packing: Typical bulk packaging includes palletized plastic 5 gallon/25 kg. pails, fiber and steel drums to 1 ton super sacks in full container (FCL) or truck load (T/L) quantities. Research and sample quantities and hygroscopic, oxidizing or other air sensitive materials may be packaged under argon or vacuum. Solutions are packaged in polypropylene, plastic or glass jars up to palletized 1986 gallon liquid totes Special package is available on request.