6061 aluminum alloy (ASTM B241, AMS 4025) large diameter tubes feature a balanced magnesium-silicon composition optimized for structural integrity and fabrication flexibility:

Alloy Chemistry:

Magnesium (Mg): 0.8-1.2% (solution strengthening)

Silicon (Si): 0.4-0.8% (precipitation hardening)

Copper (Cu): 0.15-0.40% (enhanced machinability)

Chromium (Cr): 0.04-0.35% (grain refinement)

Base Material:

Aluminum (Al): ≥97.5% (balance)

Controlled Impurities:

Iron (Fe): ≤0.7% max

Manganese (Mn): ≤0.15% max

Zinc (Zn): ≤0.25% max

Titanium (Ti): ≤0.15% max

Advanced Manufacturing Process:

Hot Extrusion: 480-520°C at extrusion ratios of 10:1 to 30:1

Cold Drawing: 10-20% reduction for dimensional accuracy

Stretch Straightening: 1.5-3% elongation for stress relief

Heat Treatment: T4/T6 temper options

Surface Finishing: Anodizing or chemical conversion coatings

Certified to AMS-QQ-A-200/9 and EN 755-7 standards with full material traceability systems.

 

 

 

Property	T4 Temper	T6 Temper	Test Standard
Ultimate Tensile Strength	180-215 MPa	260-310 MPa	ASTM E8
Yield Strength (Rp0.2)	110-130 MPa	240-280 MPa	ASTM E8
Elongation (%)	16-22%	10-15%	ASTM E8
Shear Strength	125-145 MPa	170-200 MPa	ASTM B769
Bearing Strength	365-415 MPa	480-550 MPa	ASTM E238
Fatigue Strength (10⁷)	75-95 MPa	90-115 MPa	ASTM E466
Hardness (Brinell)	65-75 HB	95-105 HB	ASTM E10
Impact Toughness	20-25 J	16-20 J	ASTM E23

 

Maintains 85% of mechanical properties at temperatures from -50°C to 150°C.

 

Temper Processing Options:

T4 Solution Treatment:

Heating: 530°C ±5°C for 1-2 hours

Quenching: Water spray (cooling rate >200°C/min)

Natural aging: 96+ hours at ambient

T6 Full Hardening:

Solution treatment: Same as T4

Artificial aging: 160-180°C for 8-12 hours

Microstructural Characteristics:

Primary Phases: β-Mg₂Si precipitates

Grain Structure: ASTM 5-7 (30-60μm)

Precipitate Size:

T4 condition: 2-10nm GP zones

T6 condition: 50-200nm β” needles

Dislocation Density: 5-7×10⁹/cm²

Recrystallization Fraction: 70-90%

 

Parameter	Standard Range	Precision Tolerance	Special Capabilities
Outer Diameter	150-1000 mm	±0.15% OD	Up to 1800 mm
Wall Thickness	5-40 mm	±10% WT	2.5-60 mm available
Length	3-20 m	+15mm/-0mm	Up to 25m sections
Ovality	≤0.6%	≤0.2% (critical)	–
Straightness	1.2 mm/m	0.4 mm/m	–
Perpendicularity	≤1.0°	≤0.5°	–
Wall Runout	≤0.8% TIR	≤0.3% TIR	–

 

Forming Capabilities:

Rotary Swaging for end forming

Mandrel Bending (R/D ratios down to 3:1)

Flange Roll Forming

Localized Annealing for complex shapes

Expansion/Reduction Operations

 

Environment	Performance Rating	Corrosion Rate	Protection Methods
Marine Atmosphere	Excellent	<0.001 mm/year	Alodine 1200S conversion
Industrial Atmosphere	Good	0.002-0.005 mm/year	Chromic acid anodizing
Fresh Water	Excellent	Negligible pitting	Powder coating
Chemical Exposure	Fair-Good	Varies by chemical	PTFE coating
Stress Corrosion	Excellent	SCC threshold >75MPa	T73 overaged temper option

 

Surface Treatment Options:

Anodizing (Type II): 5-25μm thickness

Powder Coating: 60-120μm thickness

PVDF Coating: Weather-resistant finish

Electrophoretic Deposition: Uniform coverage

Chemical Film Coating: Chromate-free options

 

Operation	Tool Material	Recommended Parameters	Surface Quality
Turning	Carbide inserts	200-350 m/min, 0.1-0.3mm/rev	Ra 0.8-2.0 μm
Drilling	HSS drills	30-70 m/min, 0.05-0.15mm/rev	±0.05 mm hole size
Milling	PCD cutters	500-800 m/min	Ra 0.4-1.5 μm
Reaming	Carbide tipped	20-50 m/min	IT7 tolerance
Tapping	Coated HSS taps	10-15 m/min	6H thread quality

 

Fabrication Advantages:

Weldability: Excellent (ER4043 filler)

Formability: High (min bend radius = 2.5T)

Brazeability: Good with proper flux

Shear and Punch: Low tool wear

Polishing Response: Mirror finish achievable

 

Preferred Welding Methods:

Gas Metal Arc Welding (GMAW):

Wire: ER4043/ER5356

Parameters: 19-23V, 150-220A

Friction Stir Welding (FSW):

Tool Speed: 400-800 RPM

Travel Speed: 120-250 mm/min

Tungsten Inert Gas (TIG):

Purity: 99.996% Argon

Electrode: 2% thoriated

Specialized Joining Systems:

Mechanical Fastening:

Hi-Tigue® collars

Rivnut® threaded inserts

Adhesive Bonding:

Epoxy structural adhesives (20-30MPa)

Methacrylate systems (15-25MPa)

Brazing Processes:

Vacuum brazing: 590-620°C

Flame brazing with aluminum-silicon fillers

 

 

 

Property	Value	Design Significance
Density	2.70 g/cm³	Weight reduction advantage
Young’s Modulus	68.9 GPa	Stiffness optimization
Poisson’s Ratio	0.33	Stress distribution control
CTE (20-100°C)	23.6 μm/m·°C	Thermal expansion matching
Thermal Conductivity	167 W/m·K	Heat dissipation capability
Electrical Conductivity	40% IACS	Electromagnetic properties
Melting Range	582-652°C	Processing parameters
Magnetic Permeability	1.00002	EM transparency

 

Comprehensive Testing:

Ultrasonic Testing: ASTM E588 standard

Hydrostatic Testing: 1.5x design pressure

Dye Penetrant Inspection: ASTM E1417

Tensile Testing: Each 500kg batch

Chemical Analysis: Optical emission spectrometry

Certification Standards:

ISO 9001:2015 Certified

AS9100 Aerospace Quality

PED 2014/68/EU Compliance

NACE MR0175/ISO 15156

AWS D1.2 Structural Welding Code

NADCAP Accredited Processing

 

 

 

 

Primary Application Sectors:

Construction structural framing

Material handling systems

Marine components and railings

Agricultural equipment frames

Renewable energy structures

Industrial machinery guarding

Transportation equipment

Architectural elements

Handling & Storage Protocols:

End caps for protection

Horizontal storage on V-blocks

Wood spacers for stacking

Protective film covering

Climate-controlled storage for T6 temper

VCI paper wrapping for long-term storage

Packaging Specifications:

Plastic sheeting + desiccant packs

Custom-fitted wooden crates

UV-resistant shrink wrapping

Non-metallic banding systems

Corner protectors for safe transport