Aluminum 6060

Aluminum 6060 is a medium-strength, highly extrudable alloy ideal for CNC machining of structural and decorative components in architectural, automotive, and consumer applications requiring superior surface finish and corrosion resistance.

Introduction to Aluminum 6060

Aluminum 6060 is a medium-strength 6xxx series aluminum alloy known for its excellent extrudability, corrosion resistance, and aesthetic surface finish. It contains lower magnesium and silicon content compared to 6061, making it easier to form, weld, and anodize while maintaining sufficient mechanical strength for architectural and structural applications.

Aluminum 6060 is commonly used in CNC machining of profiles, trim components, piping, and frames for industries such as construction, automotive, and transportation, where lightweight precision parts with decorative or anodized surfaces are required.

Chemical, Physical, and Mechanical Properties of Aluminum 6060

Chemical Composition (Typical)

Element	Composition Range (wt.%)	Key Role
Aluminum (Al)	Balance	Base metal, provides corrosion resistance and formability
Silicon (Si)	0.30–0.60	Strengthens alloy and improves extrudability
Magnesium (Mg)	0.35–0.60	Increases strength through solid solution hardening
Iron (Fe)	≤0.30	Residual element
Manganese (Mn)	≤0.10	Grain refinement
Copper (Cu)	≤0.10	Enhances machinability
Zinc (Zn)	≤0.15	Residual element
Chromium (Cr)	≤0.05	Grain structure stabilization
Others	≤0.15 (total)	Combined residuals

Physical Properties

Property	Value (Typical)	Test Standard/Condition
Density	2.70 g/cm³	ASTM B311
Melting Range	610–650°C	ASTM E299
Thermal Conductivity	200 W/m·K at 25°C	ASTM E1952
Electrical Conductivity	53% IACS at 20°C	ASTM B193
Coefficient of Expansion	23.4 µm/m·°C	ASTM E228
Specific Heat Capacity	897 J/kg·K	ASTM E1269
Elastic Modulus	69 GPa	ASTM E111

Mechanical Properties (T6 Temper)

Property	Value (Typical)	Test Standard
Tensile Strength	190–215 MPa	ASTM E8/E8M
Yield Strength (0.2%)	150–170 MPa	ASTM E8/E8M
Elongation	≥10%	ASTM E8/E8M
Hardness	60–70 HB	ASTM E10
Fatigue Strength	~80 MPa	ASTM E466
Impact Resistance	Moderate	ASTM E23

Key Characteristics of Aluminum 6060

Superior Extrudability (EN 573-3): Aluminum 6060 offers exceptional extrudability compared to other 6xxx alloys, enabling complex cross-sectional CNC profiles and seamless integration with architectural systems.

Excellent Corrosion Resistance: Suitable for exterior applications in mild to moderate environments. Forms a passive oxide layer that resists pitting and oxidation in architectural, transportation, and marine uses.

Good Surface Finish and Anodizing Response (ISO 7599): Capable of bright or decorative anodizing with uniform tone and clarity—ideal for visible trim, panels, and frames.

Moderate Strength for Lightweight Structures: Compared to 6061, it provides slightly lower strength but better formability and weldability, making it a strong candidate for aesthetic and functional components.

Weldable Using Standard Processes: Performs well with MIG and TIG welding using ER4045 or ER5356 filler, with minimal loss in corrosion resistance in the heat-affected zone (HAZ).

CNC Machining Challenges and Solutions for Aluminum 6060

Machining Challenges

Moderately Soft Alloy: May cause smearing or burring during high-speed finishing.
Chip Evacuation in Thin Profiles: Complex extrusions may trap chips, leading to tool breakage if not properly cleared.
Tool Adhesion Risks: Similar to other 6xxx alloys, requires tool coatings to avoid material build-up.

Optimized Machining Strategies

Tool Selection

Parameter	Recommendation	Rationale
Tool Material	DLC- or TiCN-coated carbide tools	Reduces built-up edge and friction
Geometry	Sharp rake angle, mirror-polished flutes	Ensures fine finish and chip removal
Cutting Speed	250–400 m/min	Prevents tool loading and thermal distortion
Feed Rate	0.10–0.25 mm/rev	Ensures dimensional control without chatter
Coolant	Mist or flood	Reduces thermal softening and improves surface finish

Aluminum 6060 Cutting Parameters (ISO 513 Compliance)

Operation	Speed (m/min)	Feed (mm/rev)	Depth of Cut (mm)	Coolant Pressure (bar)
Roughing	250–300	0.15–0.25	2.0–3.5	25–35 (Flood)
Finishing	300–400	0.05–0.10	0.2–0.8	30–50 (Mist/Flood)

Surface Treatment for Aluminum 6060 CNC Parts

Anodizing: Ideal for decorative and functional components. Thicknesses of 10–25 µm (Type II) or 25–50 µm (hard coat) improve durability.
Powder Coating: Adds 60–100 µm of commercial and consumer products protection. Compatible with RAL color standards.
Electropolishing: Useful for small profiles or brackets with critical smoothness requirements.
Passivation: Often used before painting or anodizing for optimal coating adhesion.
Brushing: Standard finishing method for visible surfaces. Achieves Ra 1.0–1.6 µm for matte textures.
Alodine Coating: Suitable for electrical enclosures and painted parts that require a conductive base.
UV Coating: Prevents yellowing or UV degradation in clear-finished display or framing parts.
Lacquer Coating: Applied for extra surface clarity or gloss on decorative trims.