Aluminum 1100
Introduction to Aluminum 1100
Aluminum 1100 is a commercially pure aluminum alloy (≥99.0% Al) known for its excellent corrosion resistance, high thermal conductivity, and superior workability. While it offers low strength compared to other aluminum grades, it remains ideal for applications where strength is secondary to formability, electrical/thermal conductivity, and chemical stability.
Widely used in CNC machining of lightweight, corrosion-resistant parts, Aluminum 1100 is common in heat exchangers, food and chemical processing equipment, signage, and electronics components.
Chemical, Physical, and Mechanical Properties of Aluminum 1100
Chemical Composition (Typical)
Element | Composition Range (wt.%) | Key Role |
|---|---|---|
Aluminum (Al) | ≥99.0 | Base metal providing high corrosion resistance and ductility |
Copper (Cu) | ≤0.05–0.20 | Slight strength enhancement |
Iron (Fe) | ≤0.95 | Residual element |
Silicon (Si) | ≤0.95 | Residual element |
Zinc (Zn) | ≤0.10 | Residual element |
Manganese (Mn) | ≤0.05 | Residual element |
Magnesium (Mg) | ≤0.05 | Residual element |
Others (Each) | ≤0.05 | Total residuals ≤0.15 |
Physical Properties
Property | Value (Typical) | Test Standard/Condition |
|---|---|---|
Density | 2.71 g/cm³ | ASTM B311 |
Melting Point | 643°C | ASTM E299 |
Thermal Conductivity | 222 W/m·K at 25°C | ASTM E1952 |
Electrical Conductivity | 59% IACS at 20°C | ASTM B193 |
Coefficient of Expansion | 24.0 µm/m·°C | ASTM E228 |
Specific Heat Capacity | 900 J/kg·K | ASTM E1269 |
Elastic Modulus | 69 GPa | ASTM E111 |
Mechanical Properties (H14 Temper)
Property | Value (Typical) | Test Standard |
|---|---|---|
Tensile Strength | 150–165 MPa | ASTM E8/E8M |
Yield Strength (0.2%) | 125 MPa | ASTM E8/E8M |
Elongation | ≥10% | ASTM E8/E8M |
Hardness | 35 HB | ASTM E10 |
Fatigue Strength | 55 MPa | ASTM E466 |
Impact Resistance | High | ASTM E23 |
Key Characteristics of Aluminum 1100
Superior Workability and Formability: 1100 is the most ductile aluminum alloy, easily drawn, spun, or bent to tight radii without cracking—ideal for deep-drawn parts and complex CNC-formed geometries.
Excellent Corrosion Resistance: Resists atmospheric and chemical corrosion, especially in neutral and mildly acidic environments. Used in food-grade and marine-adjacent applications.
Outstanding Thermal and Electrical Conductivity: Thermal conductivity of 222 W/m·K and electrical conductivity of 59% IACS makes it ideal for heat sinks, busbars, and electronic thermal management housings.
Low Mechanical Strength: Yield strength around 125 MPa, so not suitable for load-bearing applications without reinforcement. It is commonly used for cosmetic or functional parts with minimal stress.
Non-Heat Treatable: Strengthened only by cold working (strain hardening), with H14 and H18 tempers offering a good compromise between formability and durability.
CNC Machining Challenges and Solutions for Aluminum 1100
Machining Challenges
Gummy Chip Formation: High ductility can lead to poor chip breakage and smearing.
Built-Up Edge (BUE): Material tends to adhere to cutting tools, dulling edges.
Soft Surface Susceptibility: More prone to galling or cosmetic scratching during machining and handling.
Optimized Machining Strategies
Tool Selection
Parameter | Recommendation | Rationale |
|---|---|---|
Tool Material | High-speed steel or uncoated carbide | Prevents adhesion and provides sharp cutting |
Geometry | Large rake angle, sharp edge | Improves chip formation and reduces BUE |
Cutting Speed | 200–500 m/min | Enhances surface finish and chip control |
Feed Rate | 0.10–0.30 mm/rev | Maintains good chip shape without tearing |
Coolant | Light mist or dry | Reduces BUE while avoiding contamination |
Aluminum 1100 Cutting Parameters (ISO 513 Compliance)
Operation | Speed (m/min) | Feed (mm/rev) | Depth of Cut (mm) | Coolant Pressure (bar) |
|---|---|---|---|---|
Roughing | 200–300 | 0.20–0.30 | 2.0–4.0 | Dry or Mist |
Finishing | 400–500 | 0.05–0.15 | 0.2–1.0 | Dry or Mist |
Surface Treatment for Aluminum 1100 CNC Parts
Anodizing: Suitable for Type II decorative anodizing (5–25 µm). Provides good surface hardness (~200 HV) and corrosion protection. Limited color uniformity due to high purity.
Powder Coating: 60–100 µm film builds with UV and impact resistance. Requires prior surface preparation (chromating or etching) to ensure adhesion.
Electropolishing: Produces Ra ≤0.2 µm for aesthetic and hygienic finishes in food and medical-grade components.
Passivation: Not typically used alone but applied as a cleaning step before other coatings.
Brushing: Decorative finishing method for Ra 0.8–1.2 µm; ideal for signage, panels, and consumer devices.
Alodine Coating: Used where conductivity is needed along with corrosion resistance—especially in electronic enclosures.
UV Coating: 5–15 µm clear coats protect visible surfaces and reduce fingerprinting on aluminum housings.
Lacquer Coating: Applied for cosmetic finishes and protection on display-grade products and decorative surfaces.
Industry Applications of Aluminum 1100
Consumer Electronics: Appear and thermal performance are crucial to heat sinks, display bezels, and cosmetic housings.
Food and Chemical Processing: Tanks, piping, and packaging machinery requiring high purity and corrosion resistance.
Architecture: Wall panels, signage, and curtain walls that require decorative finishing and lightweight stability.
Electrical and Thermal Systems: Busbars, terminal blocks, and thermally conductive frames and enclosures.
HVAC and Heat Exchangers: Fins, ducts, and condenser components where conductivity and corrosion resistance are vital.
FAQs
What are the key machining differences between Aluminum 1100 and 6061?
Which applications benefit most from CNC machining of Aluminum 1100?
How does Aluminum 1100 perform in food-grade and cleanroom environments?
Can Aluminum 1100 be anodized for decorative purposes?
What tolerances and surface finishes are achievable with CNC machined 1100 parts?
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