Aluminum ZL105-T51
Temper
GB ZL105 · ASTM A355.0 · EN AC-45300 · JIS AC4D
T51 = t5, stress relieved by stretching
Chosen when dimensional stability and high thermal conductivity matter more than strength.
Values for the T51 condition
Other ZL105 tempers and conditions
ZL105 is listed in 9 conditions; see the grade overview at ZL105.
Compare all 9 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
As fabricated | Lowest cost condition for lightly loaded, dimensionally sensitive parts where no heat-treat distortion is acceptable. | 90 | 160 | 2.5 | 55 HB | 33 % IACS |
Cooled from hot working and naturally aged | Cheap strength/stability boost for permanent-mould parts where full solution treatment would distort thin sections. | 145 | 205 | 1.5 | 65 HB | 37 % IACS |
T51This page T5, stress relieved by stretching | Chosen when dimensional stability and high thermal conductivity matter more than strength. | 160 | 195 | 1.5 | 65 HB | 39 % IACS |
Cooled from hot working and artificially aged | Good compromise of strength and ductility for general engine and pump castings per GB/T 1173. | 180 | 250 | 1.5 | 75 HB | 37 % IACS |
T6Default Solution heat treated and artificially aged | Default stocked condition — maximum practical strength and hardness for machined structural castings. | 200 | 265 | 2 | 85 HB | 36 % IACS |
Solution treated and fully over-aged for maximum stability | Most stable, most ductile heat-treated condition for long-life hot-running castings. | 200 | 250 | 3 | 75 HB | 39 % IACS |
Solution heat treated and overaged (stabilized) | Pick for parts running hot (cylinder heads, manifolds) where dimensional stability beats peak strength. | 205 | 240 | 1.5 | 75 HB | 38 % IACS |
T6 variant, underaged | Highest strength sand-cast condition when ductility can be sacrificed. | 240 | 270 | 1 | 90 HB | 36 % IACS |
T6, heat treated by the user | Permanent-mould condition for the hardest, most wear-resistant machined surfaces. | 275 | 310 | 1 | 105 HB | 36 % IACS |
What is ZL105-T51?
ZL105-T51 is ZL105 in the T51 temper — chosen when dimensional stability and high thermal conductivity matter more than strength. ZL105-T51 has a yield strength of 160 MPa (23.2 ksi) and a tensile strength of 195 MPa (28.3 ksi) — weaker than 61% of aluminum grades. Elongation at break is 1.5% and the elastic modulus is 71 GPa (10.3 Msi). ZL105-T51 has a density of 2.71 g/cm³ (0.0979 lb/in³), heavier than 51% of aluminum grades. It melts at 546°C (1,015 °F). T6 is the default condition FabDigit quotes; T51 is available on request or by drawing note.
Advantages
- High service temperature — 175°C (347 °F), better than 83% of aluminum grades
- Conducts heat well — 165 W/m·K (95.3 BTU/hr·ft·°F), better than 79% of aluminum grades
Limitations
- Limited formability — 5/100, worse than 94% of aluminum grades
- Limited ductility — 1.5%, worse than 91% of aluminum grades
- Hard to polish — 45/100, worse than 76% of aluminum grades
ZL105-T51 properties
Typical room-temperature values for ZL105-T51; 10 are specific to this condition. Other listed values are ZL105 reference data and may not represent this condition. Bars are the position among aluminum grades.
Physical3
ZL105-T51 has a density of 2.71 g/cm³ (0.0979 lb/in³), heavier than 51% of aluminum grades. It melts at 546°C (1,015 °F).
Mechanical12
ZL105-T51 has a yield strength of 160 MPa (23.2 ksi) and a tensile strength of 195 MPa (28.3 ksi) — weaker than 61% of aluminum grades. Elongation at break is 1.5% and the elastic modulus is 71 GPa (10.3 Msi).
Thermal6
ZL105-T51 is rated for continuous service to 175°C (347 °F). It conducts heat at 165 W/m·K (95.3 BTU/hr·ft·°F), better than 79% of aluminum grades. Thermal expansion is 22.4 µm/m·K (12.4 µin/in·°F).
Electrical3
ZL105-T51 conducts electricity at 39 % IACS, better than 65% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is fair (45/100), worse than 62% of aluminum grades.
Sustainability4
Producing a kilogram of ZL105-T51 takes about 200 MJ of energy and emits 12.5 kg of CO₂ — less than 60% of aluminum grades. Typical recycled content is 70%.
Manufacturability8
ZL105-T51's machinability is fair (50/100, worse than 65% of aluminum grades); weldability good (55/100); formability not recommended (5/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with ZL105-T51
Is ZL105 easy to machine?
Machines well in T5/T6 with carbide or PCD tooling — high speed, moderate feed, flood coolant; eutectic Si is abrasive, so PCD pays off in volume production.
Can ZL105 be welded?
TIG/MIG repair welding with ER4043 or ER4145 filler is possible but the Cu content raises hot-crack risk; preheat 150–200 °C and re-solution/re-age critical parts after welding.
Can ZL105 be formed, bent or molded?
Sand, permanent-mould and low-pressure casting alloy with good fluidity and pressure tightness; feed heavy sections well and grain-refine/modify (Ti-B, Sr/Na) to hit T6 elongation.
What surface finishes work on ZL105?
Takes chromate conversion coating, primer and paint well; sulfuric anodize gives a grey, uneven film — use hard-coat only for wear, and impregnate porous castings before plating.
ZL105 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 |
|---|---|---|
| Si | 4.5 – 5.5 | 5 |
| Cu | 1 – 1.5 | 1.2 |
| Mg | 0.4 – 0.6 | 0.5 |
| Feimpurity; ≤0.5 % for permanent-mould/pressure-tight castings | ≤ 0.6 | — |
| Mnimpurity | ≤ 0.5 | — |
| Znimpurity | ≤ 0.3 | — |
| Tigrain refiner / impurity | ≤ 0.25 | — |
| Crimpurity (AA 355.0 limit) | ≤ 0.25 | — |
| Others (each/total)total impurities per GB/T 1173 | ≤ 1.1 | — |
| Al | balance | — |
ZL105-T51 — frequently asked
What is ZL105-T51 used for?
ZL105-T51 is typically used for pump bodies, cylinder heads and gearbox housings. In short: pressure-tight Cu-bearing casting; good as-cast machinability; higher hot-crack risk.
What is the yield strength of ZL105-T51?
ZL105-T51 has a typical yield strength of 160 MPa (23.2 ksi) and a tensile strength of 195 MPa (28.3 ksi) — weaker than 61% of aluminum grades. Strength varies by condition: see the 9 listed tempers.
Is ZL105-T51 easy to machine?
Reasonably — machinability is rated fair (50/100, worse than 65% of aluminum grades). Machines well in T5/T6 with carbide or PCD tooling — high speed, moderate feed, flood coolant; eutectic Si is abrasive, so PCD pays off in volume production.
Can ZL105-T51 be welded?
Yes — weldability is rated good (55/100). TIG/MIG repair welding with ER4043 or ER4145 filler is possible but the Cu content raises hot-crack risk; preheat 150–200 °C and re-solution/re-age critical parts after welding.
What surface finishes work on ZL105-T51?
Takes chromate conversion coating, primer and paint well; sulfuric anodize gives a grey, uneven film — use hard-coat only for wear, and impregnate porous castings before plating.
Can ZL105-T51 be formed, bent or molded?
Sand, permanent-mould and low-pressure casting alloy with good fluidity and pressure tightness; feed heavy sections well and grain-refine/modify (Ti-B, Sr/Na) to hit T6 elongation.
What is the maximum service temperature of ZL105-T51?
ZL105-T51 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 ZL105-T6 and ZL105-F?
T6 is the default condition — default stocked condition — maximum practical strength and hardness for machined structural castings. F: lowest cost condition for lightly loaded, dimensionally sensitive parts where no heat-treat distortion is acceptable. Yield strength is 200 MPa in T6 versus 90 MPa in F.
Sources
- ASTM B26/B26M Aluminum-Alloy Sand Castings (355.0) — ASTM (2018)
- ASM Specialty Handbook: Aluminum and Aluminum Alloys — ASM International (1993)
- ASM Handbook Vol.2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- ASM Handbook Vol.15 — Casting — ASM International (2008)
- Aluminum Association Designations and Chemical Composition Limits for Aluminum Alloys in the Form of Castings and Ingot — The Aluminum Association (2019)
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.