Aluminum LM9-TB7
Heat-treated state
BS LM9
TB7 = solution treated and stabilised
Solution treat + stabilise for maximum dimensional stability and better ductility than fully aged tempers.
Values for the TB7 condition
Other LM9 tempers and conditions
LM9 is listed in 6 conditions; see the grade overview at LM9.
Compare all 6 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
M | Sand-cast as-cast condition; slower solidification coarsens the eutectic so strength is 10–15% below chill castings. | 90 | 170 | 2 | 55 HB | 24 % IACS |
MDefault Thermomechanically controlled processed | Standard as-cast condition; pick for thin-wall pressure-tight parts where ductility and cost matter more than strength. | 95 | 190 | 3 | 60 HB | 25 % IACS |
TB7This page Solution treated and stabilised | Solution treat + stabilise for maximum dimensional stability and better ductility than fully aged tempers. | 140 | 235 | 4 | 75 HB | 26 % IACS |
Precipitation (artificially aged) from as-cast | Simple low-temperature age (~155–170 °C) that raises hardness and proof stress without solution treatment distortion. | 200 | 275 | 1.5 | 100 HB | 28 % IACS |
TF | Fully heat-treated sand castings; strength slightly below chill-cast TF because of coarser structure. | 230 | 295 | 1 | 100 HB | 29 % IACS |
Solution treated and fully artificially aged | Full T6-type treatment for highest strength and hardness; accept very low elongation and possible quench distortion. | 240 | 310 | 1.5 | 110 HB | 30 % IACS |
What is LM9-TB7?
LM9-TB7 is LM9 heat treated to TB7 — solution treat + stabilise for maximum dimensional stability and better ductility than fully aged tempers. LM9-TB7 has a yield strength of 140 MPa (20.3 ksi) and a tensile strength of 235 MPa (34.1 ksi) — weaker than 70% of aluminum grades. Elongation at break is 4% and the elastic modulus is 71 GPa (10.3 Msi). LM9-TB7 has a density of 2.65 g/cm³ (0.0957 lb/in³), lighter than 90% of aluminum grades. It melts at 557°C (1,035 °F). M is the default condition FabDigit quotes; TB7 is available on request or by drawing note.
Advantages
- High service temperature — 175°C (347 °F), better than 83% of aluminum grades
Limitations
- Low electrical conductivity — 26 % IACS, worse than 90% of aluminum grades
- Hard to polish — 45/100, worse than 76% of aluminum grades
LM9-TB7 properties
Typical room-temperature values for LM9-TB7; 21 are specific to this condition. Other listed values are LM9 reference data and may not represent this condition. Bars are the position among aluminum grades.
Physical3
LM9-TB7 has a density of 2.65 g/cm³ (0.0957 lb/in³), lighter than 90% of aluminum grades. It melts at 557°C (1,035 °F).
Mechanical13
LM9-TB7 has a yield strength of 140 MPa (20.3 ksi) and a tensile strength of 235 MPa (34.1 ksi) — weaker than 70% of aluminum grades. Elongation at break is 4% and the elastic modulus is 71 GPa (10.3 Msi).
Thermal6
LM9-TB7 is rated for continuous service to 175°C (347 °F). It conducts heat at 145 W/m·K (83.8 BTU/hr·ft·°F), better than 53% of aluminum grades. Thermal expansion is 20.5 µm/m·K (11.4 µin/in·°F).
Electrical3
LM9-TB7 conducts electricity at 26 % IACS, worse than 90% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is good (62/100), better than 67% of aluminum grades.
Sustainability4
Producing a kilogram of LM9-TB7 takes about 200 MJ of energy and emits 12 kg of CO₂ — less than 60% of aluminum grades. Typical recycled content is 80%.
Manufacturability8
LM9-TB7's machinability is fair (48/100, worse than 68% of aluminum grades); weldability good (68/100); formability not recommended (12/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with LM9-TB7
Is LM9 easy to machine?
Machinable with PCD or coated-carbide tooling at high speed and generous coolant; free eutectic silicon is abrasive and rapidly wears HSS.
Can LM9 be welded?
Readily TIG/MIG welded with 4047 or 4043 filler; preheat 150–200 °C on thick sections and re-age afterwards to recover TE/TF strength.
Can LM9 be formed, bent or molded?
Foundry alloy only — excellent fluidity and low hot-tearing suit thin-wall gravity die, sand and pressure die casting; not cold-formable.
What surface finishes work on LM9?
Takes chromate conversion coating, powder coat and paint well; conventional anodizing gives a dark, blotchy grey, so hard-anodize only where wear resistance outweighs appearance.
LM9 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 |
|---|---|---|
| Sinear-eutectic, gives fluidity | 10 – 13 | 11.5 |
| MgMg2Si age-hardening | 0.2 – 0.6 | 0.4 |
| Mnneutralises Fe needles | 0.3 – 0.7 | 0.5 |
| Feup to 1.0 % permitted for pressure die castings | ≤ 0.6 | 0.4 |
| Cukept low for corrosion resistance | ≤ 0.1 | 0.05 |
| Ni | ≤ 0.1 | — |
| Zn | ≤ 0.1 | — |
| Tigrain refinement | ≤ 0.2 | 0.1 |
| Pb | ≤ 0.1 | — |
| Sn | ≤ 0.05 | — |
| Other (each) | ≤ 0.05 | — |
| Al | balance | — |
LM9-TB7 — frequently asked
What is LM9-TB7 used for?
LM9-TB7 is typically used for die-cast housings, automotive components, thin-wall covers and end caps, pump and gearbox casings, electrical enclosures and manifolds and brackets. In short: thin-wall die-casting alloy; heat-treatable AlSi12; abrasive to tooling.
What is the yield strength of LM9-TB7?
LM9-TB7 has a typical yield strength of 140 MPa (20.3 ksi) and a tensile strength of 235 MPa (34.1 ksi) — weaker than 70% of aluminum grades. Strength varies by condition: see the 6 listed tempers.
Is LM9-TB7 easy to machine?
Reasonably — machinability is rated fair (48/100, worse than 68% of aluminum grades). Machinable with PCD or coated-carbide tooling at high speed and generous coolant; free eutectic silicon is abrasive and rapidly wears HSS.
Can LM9-TB7 be welded?
Yes — weldability is rated good (68/100). Readily TIG/MIG welded with 4047 or 4043 filler; preheat 150–200 °C on thick sections and re-age afterwards to recover TE/TF strength.
What surface finishes work on LM9-TB7?
Takes chromate conversion coating, powder coat and paint well; conventional anodizing gives a dark, blotchy grey, so hard-anodize only where wear resistance outweighs appearance.
Can LM9-TB7 be formed, bent or molded?
Foundry alloy only — excellent fluidity and low hot-tearing suit thin-wall gravity die, sand and pressure die casting; not cold-formable.
What is the maximum service temperature of LM9-TB7?
LM9-TB7 is rated for continuous use to about 175°C (347 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between LM9-M and LM9-TF?
M is the default condition — standard as-cast condition; pick for thin-wall pressure-tight parts where ductility and cost matter more than strength. TF: full T6-type treatment for highest strength and hardness; accept very low elongation and possible quench distortion. Yield strength is 95 MPa in M versus 240 MPa in TF.
Sources
- BS 1490 — Aluminium and aluminium alloy ingots and castings — BSI (1988)
- ASTM B85 / B108 (360.0, A360.0 die and permanent-mold castings) — ASTM (2021)
- ASM Handbook Vol.2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- ASM Handbook Vol.15 — Casting — ASM International (2008)
- EN 1706 — EN AC-43400 (AlSi10Mg(Fe)) / AlSi12Mg comparison data — CEN (2020)
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.