2024 T3 Aluminum Round Tube

1. Material Composition & Standards

Conforming to ASTM B221, AMS 4171, and EN 755-2 international standards, 2024-T3 aluminum round tubes feature a precision-engineered composition optimized for aerospace applications:

Primary Elements:

Copper (Cu): 3.8-4.9% (forms strengthening Al₂Cu precipitates)
Magnesium (Mg): 1.2-1.8% (enhances corrosion resistance)
Manganese (Mn): 0.3-0.9% (improves work hardening)
- Base Material:
Aluminum (Al): ≥93.5% (balance)
- Impurity Limits:
Iron (Fe): ≤0.50%
Silicon (Si): ≤0.50%
Zinc (Zn): ≤0.25%
Titanium (Ti): ≤0.15%

Third-party validation through NORSOK M650 chemical verification ensures batch-to-batch consistency. The precise Cu/Mg ratio (2.5:1 optimal) enables effective precipitation hardening during natural aging cycles. This alloy is designated as UNS A92024 under unified numbering system standards and meets Boeing BMS7-260 and Airbus AIMS 05-01-005 aerospace specifications.

2. Strength Performance

2024-T3 demonstrates exceptional strength-to-weight ratios critical for high-stress applications:

Property	Value	Test Standard
Tensile Strength (Rm)	440-485 MPa	ASTM E8
Yield Strength (Rp0.2)	290-345 MPa	ASTM E8
Shear Strength	283 MPa	ASTM B769
Compressive Yield	275 MPa	ASTM E9
Bearing Strength	580 MPa (e/D=1.5)	ASTM E238
Fatigue Endurance (5×10⁸ cycles)	138 MPa	R.R. Moore Test
Fracture Toughness (KIC)	28 MPa√m	ASTM E399

The alloy maintains:

85% of room temperature strength at 120°C
Notched sensitivity ratio of 1.25 (Kt=3)
27% higher cyclic stress capacity than 6061-T6
Fully reversible stress limit: 125 MPa (R=-1)

3. Heat Treatment State

The T3 temper sequence involves precisely controlled processing stages:

Solution Treatment:

495°C ±5°C for 20-30 minutes (α-phase dissolution)
Atmosphere-controlled furnaces with ±3°C uniformity

Quenching:

Rapid water quenching (>200°C/sec cooling rate)
Time between furnace and quench tank: <15 seconds

Cold Working:

3-5% reduction via pilgering or stretch straightening
Strain rate controlled at 0.5-2% per minute

Natural Aging:

Minimum 96-120 hours at 25°C
Relative humidity <65%

Resulting Microstructure:

Grain size: ASTM 6-7 (15-30μm)
S’ (Al₂CuMg) precipitate distribution
Dislocation density: 10¹⁰/cm²
Recrystallization threshold: 260°C

Post-forming heat treatment above 100°C is prohibited due to quench sensitivity and risk of preferential precipitation at grain boundaries.

4. Dimensions & Customization

Manufactured to meet aerospace dimensional tolerances:

Parameter	Standard Range	Precision Tolerance	Custom Options
Outer Diameter	10-200 mm	±0.05mm (>50mm OD)	Non-round profiles
Wall Thickness	1.0-15 mm	±5% WT	Tapered walls
Length	1-6 m	+0/-0.5mm	Up to 12m
Straightness	–	0.3mm/m max.	±0.1mm/m
Ovality	–	≤0.5% TIR	0.2% TIR
Perpendicularity	–	≤0.5°	≤0.1°

Processing Options:

Cutting: CNC abrasive sawing (±0.1mm) or EDM
Surface grinding for bearing fits (Ra<0.4μm)
CNC end-forming for complex joint geometries
Passivation per MIL-STD-753C

5. Corrosion Resistance Properties

Environmental Performance Ratings

Environment	Exposure Rating	Service Life*	Protection Recommendation
Marine Splash Zone	Poor (250hrs SST)	2-3 years	MIL-A-8625 Type I Anodize
Industrial Atmos.	Moderate (500hrs)	5-8 years	PEO Coating
Rural Atmosphere	Good (1000hrs)	10+ years	PVDF Coating
Alclad Version	Excellent	20+ years	5% Clad Layer

*With proper surface protection

Protection Systems:

Anodizing:

Chromic acid (Type I): 8-12μm thickness
Sulfuric acid (Type II): 15-25μm thickness
- Coatings:
Plasma Electrolytic Oxidation: 50-70μm ceramic layer (400-600 HV)
Epoxy-Polyurethane: 120μm DFT (>2000hrs salt spray)
- Cathodic Protection: Zinc-rich primers (85% Zn content)

6. Machinability Characteristics

Optimization Parameters

Operation	Tool Material	Speed (m/min)	Feed (mm/rev)	Notes
Turning	Carbide K20	150-250	0.12-0.20	7° positive rake
Milling	Carbide K10	200-400	0.05-0.15	Climb milling required
Drilling	TiAlN Coated	30-40	0.03-0.08	135° point angle
Tapping	HSS-Co5	8-12	Pitch matched	Use UNJ thread form

Performance Metrics:

Machinability index: 70% (baseline: 2011-T3=100%)
Surface roughness: Ra 0.8μm achievable
Chip control: Requires HP coolant >70 bar
Tool life expectancy: 30 minutes continuous cutting
Thermal deformation: <0.05mm at 80°C

7. Weldability & Joining Methods

Fusion Welding Not Recommended
HAZ cracking susceptibility exceeds 80% (AWS D1.2). Approved alternatives:

Friction Stir Welding (FSW)

Tool rotation: 800-1,200 RPM
Traverse speed: 60-150mm/min
Shoulder diameter: 1.2× wall thickness
Z-force control: 8-15 kN

Adhesive Bonding

Structural epoxies: FM73 or EA9394 (≥20MPa shear)
Surface prep: Chromate conversion coating (MIL-C-5541)
Curing cycle: 120°C/2hrs under 50kPa pressure

Mechanical Fastening

Hi-Lok pins: Shear strength 65kN (6mm ø)
Rivet spacing: ≥4× diameter edge distance
Collateral damage exclusion zone: 1.5× fastener diameter

9. Physical Properties

Property	Value	Test Standard
Density	2.78 g/cm³	ASTM B311
Thermal Conductivity (100°C)	121 W/m·K	ASTM E1461
CTE (20-100°C)	23.2 μm/m·°C	ASTM E228
Electrical Resistivity	50 nΩ·m	ASTM B193
Modulus of Elasticity	73.1 GPa	ASTM E111
Specific Heat (25°C)	875 J/kg·K	ASTM E1269
Latent Heat of Fusion	390 kJ/kg	–
Recrystallization Temp	260°C	–

9. Surface Quality Standards

Seamless construction: No longitudinal weld lines
Surface finish: Ra ≤0.8μm (mill finish), polishable to Ra 0.1μm
Visual inspection: Per AMS 2771 Class A
Defect limits:

No inclusions >0.3mm (ASTM B557)
Scratches <0.05mm depth
Die lines not exceeding 0.1μm Ra
- Cleaning protocols:
Ultrasonic degreasing (AMS 2646)
Acid etching for adhesive bonds

10. Certifications & Testing

Non-Destructive Testing

Ultrasonic: Level B (EN 1714) detecting flaws >0.8mm
Eddy Current: ASTM E309 (0.5mm sensitivity)
Dye Penetrant: ASME Section V Article 6
Hydrostatic: 50MPa test pressure for 30 seconds

Mechanical Testing

Tensile: ASTM E8 at multiple temperatures
Hardness: Rockwell B scale (ASTM E18)
Impact: Charpy V-notch at -65°C (min. 4J)

Certifications

Nadcap AC7117 (Materials Testing)
AS9100 Aerospace Quality
PED 2014/68/EU Category IV
ISO 9001:2015 Quality Management

Aerospace Applications: Landing gear components, missile guidance systems, actuator housings, hydraulic lines, and wing spar reinforcements where strength-to-weight ratio is critical.

Packaging: VCI paper + double-layer PE film with desiccant, ISPM 15 compliant wooden crates. Standard lead time: 8 weeks.