As China's own research and development in a specific period of history, had been widely used in national defense and high-end equipment ZL201 Series High Strength Casting Aluminum AlloyThe quintessential representative of theR14 It's a kind ofVery high room temperature strength, excellent heat resistance and good weldabilityprominent Aluminum-Copper-Manganese (Al-Cu-Mn) Alloy. The alloy is passed through theMultiple composite reinforcementIts mechanical properties after casting and heat treatment, especially tensile strength, had long been in the top level of domestic casting aluminum alloy, specifically for the manufacture ofHigh-quality castings with high loads, high operating temperatures and complex structuresAnd the design.

Standards and grades for R14

• Old national/industry codes:R14?It is a grade code originated from the internal standard or early enterprise standard of China aviation industry system, with distinctive characteristics of the era and industry.
• Corresponding national standard grade: its composition and properties are closest to national standards?ZL201A (ZAlCu5MnA).
• Grade Meaning: “R” may stand for “heat intensity” or a specific number, and “14” is a serial number. It stands for?Al-Cu-Mn-Ti?A classic formula for system alloys.
• Core features:Silicon (Si)-free or very low contentThe main strengthening element is copper (Cu), and manganese (Mn) and titanium (Ti) are added to improve the organization and heat resistance.Must be subjected to rigorous heat treatment (T5/T6) to achieve superior performance.

R14 (ZL201A) Aluminum Alloy Composition Table (Typical Range)

elemental	Content range (wt%)	functional role
Copper (Cu)	4.8-5.3	Core Strengthening Elements. Formation of θ' (Al?Cu) reinforced phase provides very high room and high temperature strength.
Manganese (Mn)	0.6-1.0	Key heat-resistant and toughening elements. Formation of heat-resistant phases such as T (Al??Cu?Mn?) improves high-temperature properties and refines grains.
Titanium (Ti)	0.15-0.35	Strong grain refiner.. Formation of Al?Ti with aluminum, which acts as a heterogeneous nucleation core and significantly refines the as-cast organization.
Cadmium (Cd) 或 Boron (B)	Trace (e.g. Cd: 0.15-0.25)	Crystal boundary modification elements. Promote the uniform precipitation of θ' phase and improve the heat treatment strengthening effect and resistance to over-aging.
Iron (Fe)	≤ 0.15	Tightly controlled impurities. The content is extremely low to avoid the formation of harmful brittle iron-rich phases.
Silicon (Si)	≤ 0.10	Tightly controlled impuritiesThe very low content is fundamental to its differentiation from Al-Si alloys. The very low content is fundamental to its differentiation from Al-Si alloys, ensuring good weldability at the expense of casting fluidity.
Aluminum (Al)	tolerance (i.e. allowed error)	Substrate material.

R14 (ZL201A) Physical and Mechanical Properties Parameter Table (Sand Casting, Typical Values for T5/T6 States)

Performance indicators	Range of values (T5/T6 state)	Performance Positioning and Comparison
intensity	Approx. 2.78 g/cm3	Higher than Al-Si alloys.
Room temperature tensile strength (Rm)	400-480 MPa	top level. Significantly higher than all conventional Al-Si system casting alloys (e.g. ZL101A about 310 MPa).
Yield strength (Rp0.2)	280-350 MPa	Again, at the top level.
Elongation (A)	4.0-8.0%	Highlighting Advantages. Maintains good plasticity at ultra-high strengths, far superior to high-strength Al-Si alloys (typically <2%).
Brinell hardness (HB)	100-120	High hardness.
High Temperature Endurance (200°C)	talented	Core Advantages. The strength retention in the range of 150-250°C is much higher than that of the Al-Si-Cu system alloys.
Weldability	favorable	Core Advantages. The low silicon content makes it less prone to weld cracking and allows for filler weld repairs.
Casting mobility	mediocre	Main drawbacks. Wide solidification range, high tendency to thermal cracking, need to use complex casting process and riser design.

Performance Enhancement Paths and Technology Keys
The performance of R14 is the result of the combination of its “harsh composition” and “precise heat treatment”:

1. Ingredient purity and precision: For impurity elements?Iron (Fe) and silicon (Si)?tolerance is extremely low, and high purity primary aluminum and intermediate alloys must be used. Trace elements?Cadmium (Cd) or boron (B)?The addition of the “secret sauce” is one of the "secret recipes" for its peak strength.
2. Harsh heat treatment regimes (T5/T6): Heat treatment is its lifeblood and usually includes:
   • Graded solid solution treatment: e.g., holding at a lower temperature (e.g., 540°C) and then increasing to a higher temperature (e.g., 550°C) to fully dissolve the Al?Cu phase and prevent overcooking.
   • Cold water quenching: Sensitive to cooling rate and requires rapid cooling to obtain a supersaturated solid solution.
   • artificial time limit: Prolonged aging at 175-185°C (e.g., 6-10 hours) to obtain the desired precipitation strengthening.
3. Advanced Casting Process: it is almost mandatory to use?Investment casting?or high quality?sand castingIn order to cope with its poor casting performance, the solidification sequence is controlled in conjunction with measures such as cold iron and aggressive cooling.

Corresponding international grades
As a classical high-strength casting alloy of the Al-Cu-Mn system, similarly positioned materials are available internationally:

• Chinese national standard:ZL201A?(GB/T 1173)
• American Standard:A201.0?(ASTM) are highly similar in performance orientation and composition.
• Russian Standard:AAЛ9?(Similar to ZL205A, higher strength, same system)
• EU standard: There is no direct counterpart, but it is part of the200 Series Casting Aluminum-Copper Alloys.

R14 (ZL201A) in the foundry industry
Its application is mainly focused on the use ofExtreme performance requirements, relatively insensitive to costThe high end of the field:

1. Aerospace and Defense (traditional core applications)
   • Aircraft structural parts: Aircraft hangers, missile wings, UAV fuselage frames, helicopter complex joints.
   • Engine Accessories: Compressor magazines, engine mounts, high strength brackets.
   • Military vehicles: Housings for transmission parts of tanks, armored vehicles, and viewer mounts.
2. High-end civilian equipment
   • High Performance Racing: Suspension mounts, steering knuckles, transmission housing.
   • Precision instruments and robots: Highly rigid and lightweight robotic arm joints, high load sensor housing.
   • Mould Industry: Blow molds, glass molds (to take advantage of their high thermal strength).
3. Special requirement parts
   • Large and complex castings requiring welding repair.
   • Operating temperature at150-250°Cbetween and require high strength components.

R14 (ZL201A) Aluminum Alloy Frequently Asked Questions

Q1: What are the biggest pros and cons of the R14?

• greatest strength:Peak of comprehensive mechanical properties-At the same time in cast aluminum alloysHighest strength, good plasticity and excellent high temperature propertiesandweldability.
• biggest drawback:Extremely poor casting workmanship(Poor fluidity, high tendency to thermal cracking),Very high production costs(Demanding raw materials and processes),General corrosion resistance(Contains high copper).

Q2: Can R14 be die-cast?

• Almost impossible and unsuitableThe high pressure die casting is not suitable for the high pressure die casting process. Its extremely poor fluidity, wide solidification temperature range and high sensitivity to thermal cracking, completely unsuitable for high-pressure die casting fast filling, rapid cooling process characteristics. It is specially designed for?Sand casting, investment casting?Designed for processes that allow fine control of the solidification process.

Q3: How is the corrosion resistance of R14? Does it need surface treatment?

• Poor corrosion resistance. The high copper content makes them much less resistant to corrosion than Al-Si and Al-Mg alloys for general atmospheric and marine environments.
• Must be surface treated. This is usually done byHard anodized或livery (on airline or company vehicle)Protecting. Its good substrate strength also provides support for thick film layer treatments.

Q4: What is the fundamental difference between R14 and common Al-Si alloys such as ZL101A and ZL104?

• These are two completely different alloy systems:
  • R14 (Al-Cu-Mn system): The QuestExtreme mechanical properties(math.) genusPoor castability and high cost, like casting alloys in “special steel”。
  • ZL101A/104 (Al-Si-Mg system): The QuestGood overall performance and processability balance(math.) genusGood castability and low costIt is.“General Engineering Plastics”。
  • The choice was made only when the Al-Si alloyStrength is absolutely impossible to meet the requirementsR14 is an Al-Cu alloy that is only considered when the structure must be molded in one piece.

Q5: Is R14 obsolete in modern manufacturing?

• Not obsolete, but highly specialized in application scenarios. With the development of high-performance Al-Si system alloys (e.g., ZL114A), aluminum matrix composites, and CNC machining (cutting from forged billets), there are more choices for many applications where R14 was necessary in the past. However, inRequirements for ultimate specific strength (strength/density), complex structures requiring one-piece molding, high operating temperatures(used form a nominal expression)Aerospace & Defense Key ComponentsOn the other hand, R14 and its upgraded grades (e.g. ZL205A) still have irreplaceable value.