T6
Solution heat-treated and artificially aged. The normal service condition for compressor blades and hot parts, giving the best heat resistance.
Heat-resistant bar
2A02 Aerospace Aluminium Rod & Bar
2A02 is a heat-resistant aluminium-copper-magnesium alloy from the Chinese GB system, used for axial compressor blades, impellers and other parts that run at raised temperatures. Metline supplies 2A02 extruded rod and bar in T6 and T4 to GB/T 3190 and GB/T 3191, with mill certificates, to buyers worldwide.
- Alloy
- 2A02 (formerly LY2)
- Tempers
- T6, T4
- Standards
- GB/T 3190 · GB/T 3191
- Use
- Compressor blades, hot parts
What 2A02 aluminium is
2A02, known before the 1990s designation reform as LY2, belongs to the Chinese duralumin family but with an unusual balance: relatively low copper (2.6 – 3.2 %) and high magnesium (2.0 – 2.4 %). This chemistry produces S-phase (Al2CuMg) precipitates that resist coarsening, giving better strength retention at temperature than the standard 2A12 (2024-type) alloy.
The alloy was developed for parts of jet engines that are too warm for ordinary aluminium but do not justify titanium: low-pressure axial compressor blades, impellers and vanes, plus brackets and fittings in warm zones. It is mainly used in the artificially aged T6 condition, sometimes in T4 for parts that will be formed or forged before final ageing.
2A02 is a national Chinese grade and has no exact Aluminum Association equivalent. Buyers outside China usually encounter it on drawings for equipment or engines designed to GB or HB standards. When a Western alternative is needed, 2618A or 2219 are the usual candidates, subject to engineering approval.
2A02 chemical composition (wt %)
Limits per GB/T 3190, the Chinese standard for wrought aluminium composition.
| Element | Limit | Comment |
|---|---|---|
| Copper (Cu) | 2.6 – 3.2 | Lower than 2A12; combines with Mg to form S-phase |
| Magnesium (Mg) | 2.0 – 2.4 | High Mg:Cu ratio favours heat-stable S-phase |
| Manganese (Mn) | 0.45 – 0.70 | Dispersoid strengthening and grain control |
| Silicon (Si) | 0.30 max | Impurity |
| Iron (Fe) | 0.30 max | Impurity |
| Zinc (Zn) | 0.10 max | Impurity |
| Titanium (Ti) | 0.15 max | Grain refiner |
| Others each / total | 0.05 / 0.10 | |
| Aluminium | Remainder |
Properties of 2A02 bar
Mechanical property minimums for 2A02 extruded bar are set by GB/T 3191 according to temper and diameter, and are reported on the mill certificate for each lot. We do not publish a single figure here because published values vary with bar size and test direction, and older data sheets mix typical and minimum values. As a guide, 2A02-T6 sits in the same strength class as 2A12-T4 at room temperature but keeps its properties better after long exposure in the 150 – 250 °C range.
| Characteristic | 2A02-T6 | Comment |
|---|---|---|
| Room-temperature strength | Medium–high | Comparable to duralumin-type alloys |
| Strength retention at 200 – 250 °C | Good | Main reason for selection |
| Ductility | Moderate | Lower in T6 than T4 |
| Corrosion resistance | Moderate | Needs anodising or coating; may show stress-corrosion sensitivity in some conditions |
| Machinability | Good | Short chips in T6 |
| Weldability | Poor | Not intended for fusion welding |
Physical data (approximate)
- Density
- about 2.75 g/cm³
- Melting range
- roughly 510 – 640 °C
- Modulus of elasticity
- about 70 – 72 GPa
Approximate values for preliminary design; confirm against your programme data.
2A02 tempers
T4
Solution heat-treated and naturally aged. More ductile; used for parts formed or upset before final ageing.
O / F
Annealed or as-fabricated stock for forging and forming, heat treated by the user afterwards.
Some older listings show T651, T3 and T8 for 2A02 rod. Those are not normal supply conditions for this alloy; if a drawing calls for them, we clarify the intended condition with the designer before quoting.
2A02 rod and bar sizes
Supply range
- Round rod
- about 6 – 250 mm diameter
- Square and hexagon bar
- to order
- Lengths
- 1 – 6 m standard, longer to order, or cut lengths
- Standards
- GB/T 3191 (extruded bar), GB/T 3190 (composition)
- Inspection
- Ultrasonic testing to GB/T 6519 or customer specification on request
Round bar weighs about 0.00216 × d² kg per metre (d in mm): a 60 mm bar is about 7.8 kg/m and a 120 mm bar about 31 kg/m.
Applications of 2A02
- Axial compressor blades and vanes in the cooler stages of turbojet and turbofan engines
- Impellers and rotating parts that run warm
- Engine-area fittings and brackets that see sustained heat
- Precision turned parts that must hold strength at operating temperature
Alternatives outside the GB system
| Alternative | Why it is considered | Caution |
|---|---|---|
| 2618A / 2618 | Best-known Western heat-resistant forging and bar alloy | Different chemistry (Fe, Ni); requires engineering approval |
| 2219 | Good strength retention at temperature, weldable | Higher density, lower room-temperature yield in some tempers |
| 2A70 | GB heat-resistant alloy similar to 2618 | Mainly a forging alloy |
None of these is a direct substitute. Any change of alloy on a flight part needs approval from the design authority.
References and standards
- GB/T 3190 – Chemical composition of wrought aluminium and aluminium alloys
- GB/T 3191 – Aluminium and aluminium alloy extruded bars
- GB/T 16474 – Designation system for wrought aluminium and aluminium alloys
- The Aluminum Association – International Alloy Designations and Chemical Composition Limits
2A02 aluminium (aluminum) rod: FAQ
What is the equivalent of 2A02 aluminium?
There is no exact ASTM or EN equivalent. 2A02 (formerly LY2) is a Chinese heat-resistant Al-Cu-Mg alloy; 2618A and 2219 are the nearest Western options for similar duties, but only with design approval.
What is 2A02 used for?
Mainly axial compressor blades, impellers and other engine parts that run at raised temperatures, plus fittings in warm zones.
Which temper is 2A02 supplied in?
Normally T6 (solution treated and artificially aged) for service parts, and T4 for parts that will be formed before final ageing.
Is 2A02 covered by ASTM B221?
No. 2A02 is a GB grade; extruded bar is supplied to GB/T 3191 with chemistry to GB/T 3190.
Can 2A02 be welded?
It is not intended for fusion welding. Parts are machined from bar or forged and joined mechanically.
Need 2A02 rod for a GB-standard drawing?
Send the diameter, temper and quantity. We will confirm availability, certification and a delivered price.
