B/6061Al · reinforced grade · default condition
B/6061Al UD-50
Properties of the UD-50 condition, compared with the other B/6061Al grades.
Baseline aerospace grade: maximum axial stiffness and strength for tubes and struts loaded along the fiber axis.
What is B/6061Al UD-50?
B/6061Al UD-50 is B/6061Al in the UD-50 grade — baseline aerospace grade: maximum axial stiffness and strength for tubes and struts loaded along the fiber axis. B/6061Al UD-50 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). B/6061Al UD-50 has a density of 2.65 g/cm³ (0.0957 lb/in³), heavier than 83% of composite grades.
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 UD-50 properties
Typical room-temperature values for B/6061Al UD-50 — 11 properties are specific to this condition; the rest are grade-level values shared by every B/6061Al grade. Each bar shows where the value sits among the composite grades in FabDigit's library — further right is higher.
Physical1
B/6061Al UD-50 has a density of 2.65 g/cm³ (0.0957 lb/in³), heavier than 83% of composite grades.
Mechanical12
B/6061Al UD-50 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 UD-50 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 UD-50 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 UD-50 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 UD-50'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.
Other B/6061Al grades and fills
B/6061Al is also supplied in 6 other conditions. The full side-by-side table is on the B/6061Al overview.
- 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
Working with B/6061Al UD-50
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.
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.
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 | — |
B/6061Al UD-50 — frequently asked
What is B/6061Al UD-50 used for?
B/6061Al UD-50 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 UD-50?
B/6061Al UD-50 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 UD-50 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 UD-50 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 UD-50?
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 UD-50 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 UD-50?
B/6061Al UD-50 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.
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. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.