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Magnesium Alloy MB15 FORGED-F

Other

ASTM MB15

As-forged wheels/brackets where fibre flow and toughness matter more than peak strength; typically followed by T5 aging if strength is needed.

High cost $$$$

Values for the FORGED-F condition

Other MB15 tempers and conditions

MB15 is listed in 5 conditions; see the grade overview at MB15.

Compare all 5 conditionsHide
Condition · open for datasheetBest forYield MPaTensile MPaElong. %HardnessConductivity
FORGED-FThis page
as-forged (die forging, no aging)
As-forged wheels/brackets where fibre flow and toughness matter more than peak strength; typically followed by T5 aging if strength is needed.2003051568 HB25 % IACS
As fabricated
Pick for as-extruded bar/profile where the small T5 strength gain is not needed and maximum ductility for later bending is wanted.2303151370 HB26 % IACS
forged then artificially aged
Standard delivery state for MB15 die forgings needing higher yield strength with good residual ductility.2303201378 HB27 % IACS
T5Default
Cooled from hot working and artificially aged
Standard stocked condition for MB15/ZK61M extruded bar, tube and profile — best strength/ductility balance without a separate solution treatment.2753401182 HB28 % IACS
Solution heat treated and artificially aged
Used mainly on forgings and heavy sections where solutionizing homogenizes segregation and gives the peak yield strength and hardness.285350988 HB29 % IACS

What is MB15 FORGED-F?

MB15 FORGED-F is MB15 in the FORGED-F condition — as-forged wheels/brackets where fibre flow and toughness matter more than peak strength; typically followed by T5 aging if strength is needed. MB15 FORGED-F has a yield strength of 200 MPa (29 ksi) and a tensile strength of 305 MPa (44.2 ksi) — stronger than 88% of magnesium alloy grades. Elongation at break is 15% and the elastic modulus is 44 GPa (6.38 Msi). MB15 FORGED-F has a density of 1.8 g/cm³ (0.065 lb/in³), lighter than 63% of magnesium alloy grades. It melts at 520°C (968 °F). T5 is the default condition FabDigit quotes; FORGED-F is available on request or by drawing note.

Advantages

  • Tough — resists crack growth — 17 MPa·√m (15.5 ksi·√in), better than 94% of magnesium alloy grades
  • High strength — 200 MPa (29 ksi), better than 88% of magnesium alloy grades
  • Ductile — tolerates forming and impact — 15%, better than 87% of magnesium alloy grades

Limitations

  • Difficult to weld — 30/100, worse than 90% of magnesium alloy grades
  • Limited service temperature — 120°C (248 °F), worse than 78% of magnesium alloy grades

MB15 FORGED-F properties

Typical room-temperature values for MB15 FORGED-F; 21 are specific to this condition. Other listed values are MB15 reference data and may not represent this condition. Bars are the position among magnesium alloy grades.

Physical3

MB15 FORGED-F has a density of 1.8 g/cm³ (0.065 lb/in³), lighter than 63% of magnesium alloy grades. It melts at 520°C (968 °F).

Density1.8 g/cm³0.07 lb/in³
Melting Point (Solidus)520°C968 °F
Liquidus Temperature635°C1,175 °F

Mechanical14

MB15 FORGED-F has a yield strength of 200 MPa (29 ksi) and a tensile strength of 305 MPa (44.2 ksi) — stronger than 88% of magnesium alloy grades. Elongation at break is 15% and the elastic modulus is 44 GPa (6.38 Msi).

Elastic (Young's) Modulus44 GPa6.4 Msi
Shear Modulus16.5 GPa2.4 Msi
Bulk Modulus45 GPa6.5 Msi
Poisson's Ratio0.35
Tensile Strength (Ultimate)305 MPa44.2 ksi
Yield Strength (0.2% offset)200 MPa29 ksi
Elongation at Break15%
Compressive Strength185 MPa26.8 ksi
Shear Strength158 MPa22.9 ksi
Fatigue Strength (Endurance Limit)130 MPa18.9 ksi
Fracture Toughness (K_IC)17 MPa·√m15.5 ksi·√in
Charpy V-Notch Impact (RT)8 J5.9 ft·lbf
Hardness, Brinell68 HB
Hardness, Vickers72 HV

Thermal6

MB15 FORGED-F is rated for continuous service to 120°C (248 °F). It conducts heat at 110 W/m·K (63.6 BTU/hr·ft·°F), better than 66% of magnesium alloy grades. Thermal expansion is 26 µm/m·K (14.4 µin/in·°F).

Thermal Conductivity110 W/m·K63.6 BTU/hr·ft·°F
Specific Heat Capacity1,000 J/kg·K0.24 BTU/lb·°F
Thermal Expansion (CTE, 20–100 °C)26 µm/m·K14.4 µin/in·°F
Latent Heat of Fusion340 J/g146 BTU/lb
Max Service Temperature (continuous)120°C248 °F
Min Service Temperature-70°C-94 °F

Electrical3

MB15 FORGED-F conducts electricity at 25 % IACS, better than 69% of magnesium alloy grades.

Electrical Conductivity25 % IACS
Electrical Resistivity6.9×10⁻⁸ Ω·m2.72 µΩ·in
Magnetic Responsenon-magnetic

Chemical & Environmental3

Corrosion resistance is poor (20/100), worse than 77% of magnesium alloy grades.

Galvanic Potential (seawater, vs SCE)-1.57 V
Corrosion ResistancePoor20/100
Chemical Resistance SummaryStable in dry air, alkalis and most organic solvents; rapidly attacked by chlorides, acids and any moisture in galvanic contact with steel, brass or carbon fibre — always coat (chemical conversion, MAO/anodic) and isolate fasteners.

Sustainability4

Producing a kilogram of MB15 FORGED-F takes about 320 MJ of energy and emits 32 kg of CO₂ — less than 74% of magnesium alloy grades. Typical recycled content is 15%.

Embodied Energy (primary production)320 MJ/kg137,575 BTU/lb
Embodied Carbon (primary production)32 kg CO₂/kg
Embodied Water500 L/kg59.9 gal/lb
Typical Recycled Content15%

Manufacturability8

MB15 FORGED-F's machinability is excellent (96/100, better than 87% of magnesium alloy grades); weldability poor (30/100); formability poor (25/100).

MachinabilityExcellent96/100
Machinability Rating (AISI 1212 = 100 %)490%
WeldabilityPoor30/100
Formability (cold)Poor25/100
CastabilityFair40/100
Brazeability / SolderabilityPoor20/100
PolishabilityGood60/100
Anodizing Responsen/a in the aluminium sense — use magnesium-specific treatments: chemical conversion (GB/T 13303 / MIL-DTL-5541-analog), HAE/Dow 17 anodic, or micro-arc oxidation for wear and corrosion protection.

Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.

Working with MB15 FORGED-F

Is MB15 easy to machine?

Outstanding machinability — high speeds, sharp positive-rake tools, generous chip clearance; never let fine chips accumulate and never use water-based coolant on dry fine swarf (fire risk), keep class-D extinguishing media at the machine.

Can MB15 be welded?

Poor fusion weldability due to Zn-induced hot cracking; prefer mechanical joining, adhesive bonding or friction stir welding — if TIG is unavoidable use ER-AZ-type or matching filler on light sections and accept property loss.

Can MB15 be formed, bent or molded?

Cold formability is very limited; extrude and forge at 300–400 °C, bend/deep-draw warm at 250–350 °C, and design for the tension–compression yield asymmetry of textured extrusions.

What surface finishes work on MB15?

Always protect: fluoride/phosphate-permanganate chemical conversion or micro-arc oxidation followed by epoxy primer and topcoat; isolate from steel, brass and carbon fibre with insulating washers/sealant to avoid galvanic pitting.

MB15 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.

ElementSpec limit (wt %)Nominal
Znprimary strengthener (MgZn2 precipitation)5 – 65.5
Zrgrain refiner0.3 – 0.90.6
Alimpurity max≤ 0.05—
Mnimpurity max≤ 0.1—
Siimpurity max≤ 0.05—
Cuimpurity max≤ 0.05—
Feimpurity max; raises corrosion rate≤ 0.05—
Niimpurity max; strongly cathodic≤ 0.01—
Others (each)total ≤0.30≤ 0.05—
Mgbalance—

MB15 FORGED-F — frequently asked

What is MB15 FORGED-F used for?

MB15 FORGED-F is typically used for aerospace forged fittings and brackets, high-performance extruded sections, motorsport structural components, UAV and missile structural fittings, machined bar-stock brackets for weight-critical assemblies and optics and sensor mounts. In short: strongest wrought magnesium listed; rare-earth Mg-Zr forging grade; poor fusion weldability.

What is the yield strength of MB15 FORGED-F?

MB15 FORGED-F has a typical yield strength of 200 MPa (29 ksi) and a tensile strength of 305 MPa (44.2 ksi) — stronger than 88% of magnesium alloy grades. Strength varies by condition: see the 5 listed tempers.

Is MB15 FORGED-F easy to machine?

Yes — machinability is rated excellent (96/100, better than 87% of magnesium alloy grades). Outstanding machinability — high speeds, sharp positive-rake tools, generous chip clearance; never let fine chips accumulate and never use water-based coolant on dry fine swarf (fire risk), keep class-D extinguishing media at the machine.

Can MB15 FORGED-F be welded?

Not readily — weldability is rated poor (30/100). Poor fusion weldability due to Zn-induced hot cracking; prefer mechanical joining, adhesive bonding or friction stir welding — if TIG is unavoidable use ER-AZ-type or matching filler on light sections and accept property loss.

What surface finishes work on MB15 FORGED-F?

Always protect: fluoride/phosphate-permanganate chemical conversion or micro-arc oxidation followed by epoxy primer and topcoat; isolate from steel, brass and carbon fibre with insulating washers/sealant to avoid galvanic pitting.

Can MB15 FORGED-F be formed, bent or molded?

Cold formability is very limited; extrude and forge at 300–400 °C, bend/deep-draw warm at 250–350 °C, and design for the tension–compression yield asymmetry of textured extrusions.

What is the maximum service temperature of MB15 FORGED-F?

MB15 FORGED-F is rated for continuous use to about 120°C (248 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.

What is the difference between MB15-T5 and MB15-F?

T5 is the default condition — standard stocked condition for MB15/ZK61M extruded bar, tube and profile — best strength/ductility balance without a separate solution treatment. F: pick for as-extruded bar/profile where the small T5 strength gain is not needed and maximum ductility for later bending is wanted. Yield strength is 275 MPa in T5 versus 230 MPa in F.

Sources

  1. ASTM B107/B107M Magnesium-Alloy Extruded Bars, Rods, Profiles, Tubes (ZK60A) — ASTM (2013)
  2. ASM Handbook Vol.2 — Properties and Selection: Nonferrous Alloys (Magnesium) — ASM International (1990)
  3. Magnesium and Magnesium Alloys, ASM Specialty Handbook — ASM International (1999)

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.