CNC Machining 2011 (AlCu6BiPb) — 2xxx Series Material
This article provides essential technical information about 2011 (AlCu6BiPb), a free-machining aluminum alloy from the 2xxx series, alloyed with copper (Cu) and containing bismuth (Bi) and lead (Pb) as chip-breaking additives. 2011 is the premier choice for high-speed CNC machining of complex parts requiring excellent surface finish and tight tolerances. Its machinability rating of 90% (compared to 100% for 6061-T6) makes it ideal for automatic screw machines and multi-spindle lathes. Dongguan Stirling Metal Products Co., Ltd. leverages this alloy’s properties for precision components in automotive, hydraulic, and electronic applications.
Chemical Composition (ASTM B211 / EN 573-3)
| Element | Content (%) | Role |
|---|---|---|
| Aluminum (Al) | Balance (approx. 93.7 – 95.5) | Base metal |
| Copper (Cu) | 5.0 – 6.0 | Primary strengthening element; enables precipitation hardening |
| Bismuth (Bi) | 0.20 – 0.60 | Chip breaker; improves machinability |
| Lead (Pb) | 0.20 – 0.60 | Chip breaker; reduces friction |
| Iron (Fe) | ≤ 0.70 | Impurity; controlled for ductility |
| Silicon (Si) | ≤ 0.40 | Impurity |
| Zinc (Zn) | ≤ 0.30 | Trace |
| Titanium (Ti) | ≤ 0.15 | Grain refiner |
| Others (each) | ≤ 0.05 | – |
| Others (total) | ≤ 0.15 | – |
Mechanical Properties (Typical, T3 and T8 Tempers)
| Property | T3 Temper | T8 Temper | Standard (ASTM B211) |
|---|---|---|---|
| Tensile Strength (MPa) | 310 – 350 | 370 – 410 | ≥ 310 (T3) |
| Yield Strength (0.2% offset, MPa) | 240 – 280 | 300 – 340 | ≥ 240 (T3) |
| Elongation (%) | 10 – 15 | 8 – 12 | ≥ 8 (T3) |
| Hardness (HBW) | 95 – 110 | 115 – 130 | – |
| Shear Strength (MPa) | 190 – 210 | 220 – 240 | – |
| Modulus of Elasticity (GPa) | 71 | 71 | – |
| Fatigue Strength (MPa, 10^7 cycles) | ~110 | ~130 | – |
CNC Machining Parameters
2011 is designed for high-speed machining with excellent chip control. Use sharp, polished carbide tools and high cutting speeds to maximize productivity. The following parameters are for H13 carbide with TiB2 or DLC coating.
| Operation | Cutting Speed (m/min) | Feed (mm/rev) | Depth of Cut (mm) | Coolant |
|---|---|---|---|---|
| Turning (rough) | 350 – 550 | 0.12 – 0.30 | 1.0 – 3.0 | Water-miscible (5-8%) |
| Turning (finish) | 450 – 650 | 0.05 – 0.15 | 0.2 – 0.5 | Mist or air blast |
| Milling (rough) | 300 – 500 | 0.10 – 0.25 (mm/tooth) | 1.0 – 2.0 | Water-miscible |
| Milling (finish) | 400 – 600 | 0.04 – 0.12 (mm/tooth) | 0.2 – 0.5 | Mist or air blast |
| Drilling | 150 – 250 | 0.08 – 0.20 | – | Water-miscible |
Applications
- Automotive: Fuel system components, hydraulic valve bodies, and sensor housings requiring complex geometries and tight tolerances.
- Hydraulics & Pneumatics: Fittings, connectors, and manifold blocks where pressure tightness is critical.
- Electronics: Connector pins, terminals, and heat sinks requiring high electrical conductivity and precision threading.
- General Machining: Screw machine parts, bushings, and fasteners produced in high volumes.
- Custom CNC Parts: Complex prototypes and production runs with demanding surface finish requirements.
CNC Machining Tips
Tool Material: Carbide (ISO K10/K20) with TiB2 or DLC coating to reduce friction and BUE. For high-volume production, polycrystalline diamond (PCD) tools extend tool life significantly.
Coating: TiB2 (titanium diboride) is preferred for aluminum; DLC also works well. Avoid TiAlN as it reacts with aluminum.
Coolant: Water-miscible coolant at 5-8% for roughing; mist or dry for finishing to prevent staining. 2011 contains lead, so coolant filtration is important for environmental compliance.
Heat Treatment: 2011 is precipitation hardenable. T3 (solution heat treated and cold worked) is standard for machining. T8 (solution heat treated, cold worked, and artificially aged) offers higher strength but reduced machinability.
Chip Control: The Bi and Pb additives produce small, broken chips. Use positive rake inserts and high feed rates. Avoid stringy chips by maintaining sharp tools.
Surface Finish: Achievable Ra 0.2 – 0.8 µm. For threaded parts, use thread rolling after machining for improved fatigue life.
Why Choose Professional CNC Machining
Precision CNC machining of 2011 aluminum requires expertise in high-speed machining, chip management, and tolerance control. Dongguan Stirling Metal Products Co., Ltd. utilizes Swiss-type lathes and multi-axis machining centers to produce complex parts with ±0.005 mm accuracy. Our one-stop service includes material sourcing (with MTC), machining, surface treatment (anodizing, passivation), and quality inspection (CMM, optical comparators). From prototype to high-volume production, we deliver consistent quality for your 2011 components.
Published: 2025-03-21
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