Composite
B/6061Al
Properties, grades, machining, finishes and uses — values shown for the UD-50 condition.
B/6061Al is a continuous boron-monofilament reinforced 6061 aluminum laminate, consolidated from foil-fiber-foil stacks in unidirectional (UD-50, UD-45), cross-ply (CP-0/90) and quasi-isotropic layups, in F and T6 conditions.
Reference datasheet — B/6061Al is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
What is B/6061Al?
B/6061Al is a continuous boron-monofilament reinforced 6061 aluminum laminate, consolidated from foil-fiber-foil stacks in unidirectional (UD-50, UD-45), cross-ply (CP-0/90) and quasi-isotropic layups, in F and T6 conditions. It is used where specific stiffness dominates: 210 GPa modulus and 1380 MPa tensile strength at 2.65 g/cm³, with 950 MPa yield, 100 W/m·K and service to about 300 °C, mainly as tubular struts and stiffened skins. Elongation is 0.75%, carbide machining and fusion welding are ruled out, and supply is limited to legacy aerospace work; high-modulus CFRP or graphite/aluminum covers most new designs. B/6061Al has a density of 2.65 g/cm³ (0.0957 lb/in³), heavier than 83% of composite grades. B/6061Al has a yield strength of 950 MPa (138 ksi) and a tensile strength of 1,380 MPa (200 ksi) — stronger than 94% of composite grades. Elongation at break is 0.75% and the elastic modulus is 210 GPa (30.5 Msi).
What is B/6061Al used for?
- space shuttle struts
- aircraft fuselage stiffeners
- satellite booms
Advantages
- High strength — 950 MPa (138 ksi), better than 94% of composite grades
- Tough — resists crack growth — 35 MPa·√m (31.9 ksi·√in), better than 93% of composite grades
- Conducts heat well — 100 W/m·K (57.8 BTU/hr·ft·°F), better than 88% of composite grades
- Stiff — 210 GPa (30.5 Msi), better than 78% of composite grades
- Good UV / weathering resistance — 95/100, better than 77% of composite grades
Limitations
- High embodied carbon — 60 kg CO₂/kg, worse than 96% of composite grades
- Needs corrosion protection — 40/100, worse than 95% of composite grades
- Difficult to machine — 8/100, worse than 93% of composite grades
- Limited ductility — 0.75%, worse than 83% of composite grades
- Heavy — 2.65 g/cm³ (0.0957 lb/in³), worse than 83% of composite grades
B/6061Al properties
Typical room-temperature values for B/6061Al-UD-50 (baseline aerospace grade: maximum axial stiffness and strength for tubes and struts loaded along the fiber axis), compiled from standards, handbooks and producer data. Each bar shows where the value sits among the composite grades in FabDigit's library — further right is higher. Other conditions have their own pages: see tempers.
Physical1
B/6061Al has a density of 2.65 g/cm³ (0.0957 lb/in³), heavier than 83% of composite grades.
Mechanical12
B/6061Al has a yield strength of 950 MPa (138 ksi) and a tensile strength of 1,380 MPa (200 ksi) — stronger than 94% of composite grades. Elongation at break is 0.75% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal5
B/6061Al is rated for continuous service to 300°C (572 °F). It conducts heat at 100 W/m·K (57.8 BTU/hr·ft·°F), better than 88% of composite grades. Thermal expansion is 6.2 µm/m·K (3.44 µin/in·°F).
Electrical1
B/6061Al has an electrical resistivity of 6×10⁻⁸ Ω·m.
Chemical & Environmental3
Corrosion resistance is fair (40/100), worse than 95% of composite grades. UV resistance is excellent.
Sustainability3
Producing a kilogram of B/6061Al takes about 900 MJ of energy and emits 60 kg of CO₂ — more than 95% of composite grades. Typical recycled content is 0%.
Manufacturability2
B/6061Al's machinability is not recommended (8/100, worse than 93% of composite grades).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
B/6061Al grades and fills
B/6061Al is supplied in 7 conditions, each with its own property set. Open one for its full datasheet. UD-50 is what FabDigit quotes unless the drawing says otherwise.
- UD-50DefaultBaseline aerospace grade: maximum axial stiffness and strength for tubes and struts loaded along the fiber axis.950 MPa yield
- UD-45Slightly lower fiber loading used where consolidation quality and transverse ductility matter more than peak stiffness.1,250 MPa tensile
5 further conditions are listed below with a summary only.
| Condition | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
UD-50Default unidirectional, ~50 vol% boron fiber, 0° properties | Baseline aerospace grade: maximum axial stiffness and strength for tubes and struts loaded along the fiber axis. | 950 | 1,380 | 0.75 | — | 100 W/m·K |
unidirectional, ~45 vol% boron fiber, 0° properties | Slightly lower fiber loading used where consolidation quality and transverse ductility matter more than peak stiffness. | — | 1,250 | 0.8 | — | 110 W/m·K |
unidirectional laminate loaded across the fibers | Use these numbers for any load component perpendicular to the fiber axis — they are matrix/interface controlled and are the design driver for pressure or off-axis loading. | — | 120 | 0.5 | — | 70 W/m·K |
Cross-ply 0/90 laminate | Balanced biaxial layup for skins and panels needing similar stiffness in two orthogonal directions. | — | 700 | 0.7 | — | 90 W/m·K |
Quasi-isotropic 0/±45/90 laminate | Pick when loading direction is uncertain or shear/bearing loads dominate; sacrifices about 40 % of axial stiffness. | — | 480 | 0.9 | — | — |
as-diffusion-bonded (matrix left in the hot-consolidation/annealed condition) | Default delivery state straight from the hot press/autoclave; softest matrix, lowest transverse and shear strength but best damage tolerance. | — | 1,330 | 0.85 | — | — |
matrix solution treated and artificially aged after bonding | Post-bond aging of the 6061 matrix; raises transverse, shear and bearing strength with little change in 0° strength — use where off-axis or joint loads govern. | — | 1,450 | 0.6 | — | — |
Working with B/6061Al
Is B/6061Al easy to machine?
Effectively unmachinable with carbide — use abrasive waterjet, diamond-plated cutters/grinding, ultrasonic or EDM (EDM works only because the matrix is conductive), and never drill fiber-cut holes where load is carried.
Can B/6061Al be welded?
Cannot be fusion welded (fiber degradation and matrix wash-out); join by diffusion bonding, brazing at low temperature, adhesive bonding, or by co-bonding titanium/aluminium end fittings and mechanical fasteners in matrix-rich pads.
Can B/6061Al be formed, bent or molded?
Formed only during consolidation — foil–fiber–foil layup hot pressed or autoclave diffusion bonded around 500–520 °C; no cold forming after bonding, tubes are made on a mandrel to final shape.
Strength versus weight in the composite family
Yield strength against density for every composite grade FabDigit runs. B/6061Al is highlighted; hover a dot for its name, or open the interactive family chart.
B/6061Al chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| boron fiber (W-cored monofilament, 100–1wt% ≈ 45–50 vol%; CVD boron on ~12 µm tungsten core | 40 – 55 | 48 |
| Wtungsten fiber core, unavoidable | 0.3 – 0.9 | 0.6 |
| Mg0.8–1.2 % of the 6061 matrix fraction | 0.4 – 0.65 | 0.5 |
| Si0.40–0.8 % of matrix | 0.2 – 0.45 | 0.3 |
| Cu0.15–0.40 % of matrix | 0.07 – 0.22 | 0.14 |
| Cr0.04–0.35 % of matrix | 0.02 – 0.19 | 0.1 |
| Tioptional Ti foil interleaf / diffusion barrier in some layups | 0 – 3 | 0 |
| Al6061 matrix foil, balance | balance | — |
What surface finishes work on B/6061Al?
Matrix-rich surfaces can be chromate-conversion coated, anodized or painted like 6061; exposed fiber ends and Ti interleaves must be sealed or capped with aluminium cladding to prevent galvanic pitting.
Equivalent designations
Standards and trade names that resolve to B/6061Al in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- Also called
- B/6061Al
How much does B/6061Al cost?
B/6061Al is a high-cost composite ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
B/6061Al — frequently asked
What is B/6061Al used for?
B/6061Al is typically used for space shuttle struts, aircraft fuselage stiffeners and satellite booms. In short: extreme specific stiffness; legacy aerospace laminate; effectively unmachinable.
What is the yield strength of B/6061Al?
B/6061Al has a typical yield strength of 950 MPa (138 ksi) and a tensile strength of 1,380 MPa (200 ksi) — stronger than 94% of composite grades. Strength varies by condition: see the 7 listed tempers.
Is B/6061Al easy to machine?
Not especially — machinability is rated not recommended (8/100, worse than 93% of composite grades). Effectively unmachinable with carbide — use abrasive waterjet, diamond-plated cutters/grinding, ultrasonic or EDM (EDM works only because the matrix is conductive), and never drill fiber-cut holes where load is carried.
Can B/6061Al be welded?
Cannot be fusion welded (fiber degradation and matrix wash-out); join by diffusion bonding, brazing at low temperature, adhesive bonding, or by co-bonding titanium/aluminium end fittings and mechanical fasteners in matrix-rich pads.
What surface finishes work on B/6061Al?
Matrix-rich surfaces can be chromate-conversion coated, anodized or painted like 6061; exposed fiber ends and Ti interleaves must be sealed or capped with aluminium cladding to prevent galvanic pitting.
Can B/6061Al be formed, bent or molded?
Formed only during consolidation — foil–fiber–foil layup hot pressed or autoclave diffusion bonded around 500–520 °C; no cold forming after bonding, tubes are made on a mandrel to final shape.
What is the maximum service temperature of B/6061Al?
B/6061Al is rated for continuous use to about 300°C (572 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does B/6061Al cost?
B/6061Al is a high-cost composite ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- ASM Handbook Vol. 21: Composites — Metal Matrix Composites — ASM International (2001)
- Engineered Materials Handbook Vol. 1: Composites (boron/aluminum section) — ASM International (1987)
- MIL-HDBK-17 Vol. 4 / CMH-17-4B, Metal Matrix Composites — US DoD / SAE (2013)
- Boron monofilament and B/Al laminate product data — Textron Specialty Materials (Specialty Materials Inc.) (2019)
- ASTM B209 / AA Teal Sheets — 6061 matrix alloy composition — ASTM / Aluminum Association (2021)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.