Introduction to 2A16 Aluminum Alloy
2A16 aluminum alloy (formerly known as LY16) is a typical heat-resistant duralumin in the Al-Cu-Mn series, renowned for its exceptional high-temperature mechanical properties and thermal stability. Widely used in industrial applications requiring long-term load-bearing in high-temperature environments, this alloy offers a unique combination of strength and durability. Below is a detailed overview covering its basic information, chemical composition, properties, processing techniques, and applications.
I. Basic Information
Material Name: 2A16 Aluminum Alloy
Former Designation: LY16 (“LY” is the pinyin abbreviation for “duralumin,” an early Chinese naming convention for hard aluminum alloys)
Standards Compliance: Primarily adheres to Chemical Composition of Wrought Aluminum and Aluminum Alloys (YS/T 439-2001), with reference to general aluminum alloy standards such as GB/T 3190.
II. Chemical Composition (Mass Fraction, %)
Designed with copper as the primary alloying element and supplemented by manganese to enhance heat resistance, 2A16’s composition is carefully balanced:
Element Content Range Element Content Range
Aluminum (Al) Balance Copper (Cu) 6.0% – 7.0%
Manganese (Mn) 0.4% – 0.8% Magnesium (Mg) ≤0.05%
Silicon (Si) ≤0.30% Iron (Fe) ≤0.30%
Zinc (Zn) ≤0.10% Titanium (Ti) 0.10% – 0.20%
Other Impurities Single ≤0.05%, Total ≤0.10% – –
Note: Strict control of magnesium (Mg) minimizes the precipitation of brittle phases at high temperatures, while titanium (Ti) refines grain structure to improve hot workability.
III. Core Properties
1. Mechanical Properties (After Heat Treatment, e.g., Quenching + Artificial Aging)
Tensile Strength: ≥440 MPa (retains high strength at elevated temperatures, ~380 MPa at 200°C)
Yield Strength: ≥315 MPa
Elongation (δ5): ≥10% (sufficient plasticity for forming processes)
Hardness (HB): ≥120 (significantly enhanced after aging treatment)
2. Key Characteristics
Exceptional Heat Resistance: As a premier heat-resistant aluminum alloy, it maintains stable mechanical properties when used continuously below 250°C, excelling particularly in the 150-200°C range—far surpassing common duralumin alloys like 2A12.
Heat-Treatable for High Strength: Through “quenching (heating to 510-530°C followed by water quenching) + artificial aging (160-170°C for 10-16 hours),” strength and hardness are dramatically increased via the precipitation of 强化 phases such as Al₂Cu.
Excellent Hot Workability: High plasticity at elevated temperatures allows for seamless forging, rolling, and extrusion into plates, bars, and forgings. Moderate cold workability enables machining operations like cutting and drilling.
Weldability and Corrosion Resistance: Weldability exceeds that of some high-copper aluminum alloys, though post-weld heat treatment is required to restore strength. Moderate corrosion resistance necessitates surface treatments (e.g., anodizing, painting) to prevent pitting.
IV. Processing Guidelines
Hot Working:
Forging temperature: 380-450°C, ideal for complex-shaped, high-strength heat-resistant forgings (e.g., engine mounts).
Rolling and extrusion: Conducted at 400-480°C to produce sheets, tubes, and profiles.
Heat Treatment:
Quenching is critical to ensure uniform solid solution and rapid cooling to prevent premature precipitation of 强化 phases.
Aging parameters (temperature and time) must be strictly controlled to avoid over-aging, which reduces strength.
Surface Treatment:
Anodizing forms a dense oxide layer to enhance corrosion and wear resistance; painting is suitable for aesthetic requirements.
V. Major Applications
Aerospace Industry: Core material for aircraft engine compartment components, structures near combustion chambers, missile tail fins, and other high-temperature load-bearing parts, leveraging its ability to maintain integrity under extreme thermal conditions.
Ordnance Manufacturing: Used in artillery breeches, gun barrel heat shields, and other components requiring high temperature resistance and strength.
Other High-Temperature Scenarios: Industrial furnace supports, high-temperature pipeline connectors, and 替代 lightweight alternatives to steel in applications up to 200°C.
Summary
The primary advantage of 2A16 (LY16) aluminum alloy lies in its outstanding high-temperature stability and strength, making it ideal for load-bearing structures in elevated-temperature environments. Its performance is highly sensitive to composition control and heat treatment processes. In applications, corrosion protection measures should be implemented based on the service environment, and proper processing techniques must be employed to maximize its potential.