AA12 Aluminum Alloy
LY12, now commonly called 2A12, is equivalent to 2024. It is mainly composed of the Al-Cu-Mg system with the following chemical composition:
- Silicon: 0.5%
- Iron: 0.5%
- Copper: 3.8-4.9%
- Manganese: 0.0-0.9%
- Magnesium: 1.2-1.8%
- Chromium: 0.10%
- Nickel: N/A
- Zinc: 0.25%
- Titanium: 0.15% (5)
- Other elements: 0.15%
- Aluminum: The rest
Observation:
(1) Properties of combination elements are expressed as the highest percentage unless a range or minimum value is listed.
(2) To establish appropriate numerical limits, observed or calculated values obtained from the analysis are based on standard rules (ANSI Z25.1) to represent a clear range.
(3) Unless it is not an alloy, the quantity of elements specified in the alloy is normally indicated in the analysis report. However, if the presence of other elements or the overabundance of some elements is suspected during the analysis process, new analyzes must be carried out until confirmation.
(4) The aluminum content in unalloyed aluminum that has not been refined is equal to the total amount of other metals and the difference with 100% pure aluminum – the difference is about 0.01% or a little more (the second decimal place after the percentage).
(5) May contain up to 0.20% zirconium and titanium.
The common plate standard is AMS-QQ-A-250/4 (uncoated) and AMS-QQ-A-250/5 (coated), mainly used for aircraft structures, rivets, missile components, wheel hubs trucks, propeller components and other structural parts.
Sample size: bar diameter (square bar, diameter of circle inscribed in hexagonal bar) ≤ 22.
Aluminum Alloy 2024
Standard: JIS H4000-1999
Chemical composition:
- Silicon (Si): 0.50%
- Iron (Fe): 0.50%
- Copper (Cu): 3.8-4.9%
- Manganese (Mn): 0.30-1.0%
- Magnesium (Mg): 1.2-1.8%
- Chromium (Cr): 0.10%
- Zinc (Zn): 0.25%
- Aluminum (Al): The rest
Mechanical properties:
Tensile strength (σb) ≥ 390 MPa
Yield strength (σ0.2) ≥ 245 MPa
Sample size: all wall thicknesses
Note: Tube material, at room temperature, longitudinal.
Main features and scope of application:
This is a hard, high-strength aluminum that can be strengthened by heat treatment. Its plasticity is moderate in the quenched and tempered states. It has good resistance to spot welding, but there is a tendency to form intergranular cracks during gas welding.
After quenching and cold work hardening, the alloy still has good machinability, while its machinability is poor after annealing. Its corrosion resistance is not high, so it is often treated with anodizing and painting or surface coated with aluminum to improve its corrosion resistance.
It is mainly used to manufacture various high-load parts and components (excluding stampings and forgings), such as skeleton parts, cladding, partitions, ribs, spars, rivets and other parts working below 150°C in aircraft.
2A12 Aluminum Alloy
Standard: GB/T 3191-1998
Chemical composition:
- Aluminum (Al): The rest
- Silicon (Si): ≤ 0.50%
- Copper (Cu): 3.8-4.9%
- Magnesium (Mg): 1.2-1.8%
- Zinc (Zn): ≤ 0.30%
- Manganese (Mn): 0.30-0.9%
- Titanium (Ti): ≤ 0.15%
- Nickel (Ni): ≤ 0.10%
- Iron (Fe): 0.000-0.500%
- Iron + nickel (Fe+Ni): 0.000-0.500%
Note: Individual element: ≤ 0.05%; Total: ≤ 0.10%
Features and application range:
2A12 aluminum alloy is a high-strength hard aluminum that can be strengthened by heat treatment.
It has moderate plasticity in the annealed, quenched, tempered and hot states. It has good resistance to spot welding, but there is a tendency to form intergranular cracks during gas or argon arc welding.
After quenching and cold work hardening, the alloy still has good machinability, while its machinability is low in the annealed state. Its corrosion resistance is not high, so it is often treated with anodizing and painting or surface coated with aluminum to improve its corrosion resistance.
It is mainly used to manufacture various high-load parts and components (excluding stampings and forgings), such as skeleton parts, cladding, partitions, ribs, spars, rivets and other parts working below 150°C in aircraft.
Mechanical properties of 2A12 aluminum alloy:
- Tensile strength (σb): ≥410 MPa
- Yield strength (σ0.2): ≥265 MPa
- Elongation (δ5): ≥12%
Note: The longitudinal mechanical properties of the bar at room temperature.
