Introduction
Do you know understanding the properties of various die casting metals is important in choosing the right one for your products? Die casting is a process that involves infusing liquid or molten metal into a mold cavity to produce high-quality products. The liquid metal is an essential component of this process and to make effective and efficient products, the liquid metal must be fit for the final products.
This article looks into various die casting metals. It gives an in-depth understanding of their properties, importance, and suitable applications. Keep reading this article to obtain the appropriate knowledge required to select the right metal for your products.
What is Die Casting
Die casting is a process used for the production of metals. This process is very efficient in manufacturing detailed and long-lasting components. This process works under high pressure by injecting liquid or molten metal into a mold or die cavity. Although there are other metal casting processes such as sand casting, lost-wax casting, centrifugal casting, etc., die casting appears to be more effective as it overrides these other metal casting processes because of its efficiency, speed, and accurate dimension.
This method is fit for high-volume, high-quality, intricate, and finely detailed metal parts which makes it a top-pick in the automobile, military, and electronic industries. The major die casting alloys are aluminum, zinc, and magnesium. To begin the process of die casting; the preferred die casting metal has to be properly heated until it becomes liquefied. Using a die casting machine, the liquid metal is then injected into every part of the die casting steel mold cavity.
Afterward, the metal is left to cool and while it solidifies, the die opens up and the solidified metal is ejected from the mold. There are two main types of die casting namely; hot chamber and cold chamber. The hot chamber is used for metals such as magnesium and zinc due to their low melting point, while the cold chamber is used for metals like aluminum that require elevated melting points.
Die Casting Material Selection Considerations
The die casting process is very efficient. Hence, it is vital to choose the appropriate material for the process. Doing this helps to ensure that the end product achieves the set standards of durability, precision, accurate measurements. These essential factors are important in selecting the appropriate die casting materials.
Physical Properties
Mechanical properties such as tensile strength, hardness, and resistance are important parameters to look out for effective die casting. For instance, aluminum alloys have a high strength-to-weight ratio (an important factor for automobile and aerospace components), while zinc alloys are commonly known for dimensional accuracy and ease of machining.
Resistance to Corrosion
The ability of the die cast material to withstand harsh environmental conditions is important. When aluminum alloys are exposed to air, a protective oxide layer is formed and it helps to prevent oxidation and corrosion. Some other alloys offer corrosion resistance, however, aluminum alloys remain the best when it comes to this property.
Cast Ability and Fluidity of the Material
Fluidity is the metal’s ability to flow perfectly into all parts of the mold. This ensures that the intended final product is accurate in all dimensions. The material should not wane in size during cooling and ejection.
Melting Point and Thermal Conductivity
The die cast material’s melting point is used to determine if they are suitable for the available die casting machine. Materials with high melting points require heat-resistant equipment. It is important to note that thermal conductivity of a material affects how the material cools and solidifies.
Types of Die Casting Metal
There are various types of Die casting metals but for this article, we will be looking at the three major casting materials list ones which are the aluminum, zinc, and magnesium die casting alloys.
Aluminum Die casting Alloys
Die casting aluminum alloys are unique because of the properties they possess. Such properties make them suitable for the production of complex and high-quality components. Aluminum alloys have an inherent corrosion resistance ability making them withstand harsh conditions. Their high strength-to-weight ratio also makes them fit for highly demanding applications. Besides these, their excellent fluidity allows for the manufacturing of intricate thin-walls. Aluminum die casting alloys price ranges from US$ 1.15- US$5.00 depending on the size of the alloy. The following are lists of aluminum die casting alloys.
A380
A380 aluminum alloy is one of the very common and widely used die casting alloys. Its composition majorly includes aluminum with 7.5-9.5% silicon, 3-4% copper, and small amounts of iron, magnesium, etc. It is popularly known for its ability to form desired shapes when injected into the mold, great mechanical properties, high tensile strength, and durability which makes it a common preference in the automobile industry where its components must be able to tolerate stress.
It has an anti-corrosive property which keeps it functioning when exposed to chemicals and air. In addition to this, it also has good heat and electricity conductivity making its application in electrical appliances, and telecommunications beneficial. Lastly, its low weight makes it effective for applications that require low mass for quality performance.
A383
A383 alloy is very similar to the A380. It is known for its exceptional casting traits making it perfect for intricate and thin-walled designs. This is because its optimal fluidity makes it flow properly into every part of the mold cavity. This property of A383 and its composition makes it resistant to hot cracking while it is being cooled in the die cavity.
Similar to A380, A383 has good corrosion resistance and mechanical strength. Although its strength cannot be compared with some other aluminum alloys, it is useful for die cast material that may not necessarily require extreme strength. It is used in industrial equipment like pump housings, electronics, and home appliances.
A413
This die casting alloy is composed of 11-13% silicon making it a high-silicon aluminum alloy, 1-3% copper, and other trace elements like magnesium, manganese, nickel, and so on. The silicon content makes it pressure resistant and contributes to the fluidity of the alloy. Its tensile strength is also strong but a little lower than A380.
Like other aluminum die casting alloys, A413 has high thermal and electrical conductivity which enhances its efficiency in industries where heat conduction is crucial for the performance of their equipment. A413 has excellent corrosion resistance but may sometimes require additional surface finishing treatment like powder coating. It is used in the production of pressure vessels, cylinder heads, heat sinks, and other appliances where efficient heat management is vital.
B390
The B390 die casting alloy is silicon-rich, containing about 16-18% silicon and trace amounts of other elements like copper, nickel, etc. This high concentration of silicon gives it a notable feature – its outstanding wear resistance – which helps the alloy fight against wear and abrasion. In addition to its fluidity conferring excellent castability, B390 die casting metal provides high tensile strength compared to most of the other aluminum die casting alloys which makes it ideal for equipment that must withstand high load and stress.
Like A380, it offers a fair corrosion resistance when rated with other aluminum alloys. Its major applications are in the production of engine blocks, pistons, gearboxes, structural parts in aerospace components (due to its wear resistance), excavator components, and hydraulic parts (due to its high tensile strength).
AC46100
This aluminum die casting alloy contains 8-11% silicon, 2-4% copper, smaller amounts of magnesium, and other elements, of course with aluminum. It offers a remarkable tensile strength which makes it good for applications that require good mechanical strength. Coupled with this, its wear resistance is not as high (but relatively good) compared to B390. Hence, it can only manage moderate abrasive conditions.
It is known for its optimal use in demanding applications like valves, pump housings, and automobiles. Like others, it provides good fluidity for excellent castability. Lastly, its low melting point makes it unsuitable for applications that need high temperatures.
AC46500
Like AC46100, asides aluminium, it consists of about 8-11% silicon, 2-4% copper, iron, zinc, and other elements. It demonstrates great strength at extreme temperatures up to 200°C. This is very good for appliances with high operating temperatures. AC46500 exhibits easier machining making it easy to achieve desired shapes and finishes. This makes it great for components that require precise details.
The low hot tearing feature of this alloy allows for the production of quality casts without cracks. In addition, its good pressure tightness makes it desirable for equipment that contains fluids or gas. AC46500 is also known for its moderate thermal conductivity (it is not as high as that of A360 or A380).
ADC 12
ADC 12 diecast material is known for its great thermal and electrical conductivity, low shrinkage, ease of castability, hot tear resistance, excellent filling property and its ability to work under high/ low pressure. It possesses an ultimate tensile strength of 310MPa making it functional optimally even at high temperatures. ADC 12 contains about 9.5-11.5% silicon, 2.3% copper and other trace elements. It is used in equipment such as electrical appliances, valves, sensory brackets, telecommunication, LED lighting, and so on.
ADC 10
ADC 10’s silicon content ranges from 3-4% and 7.5-9.5% copper. ADC 10 can be used in the production of high-quality components while minimizing cost. It is harder than some aluminum alloys and the final cast products stay in a good state if properly handled. ADC 12 and other ductile alloys offer better fluidity and tensile strength than ADC 10 because of their higher silicon content.
With good corrosion resistance, maintenance of strength at moderate temperatures due to its anti-soldering property, and affordability, ADC 10 can be used in sports equipment, automotive for engine parts, electronics, wheels, steering components, etc. Also, it exhibits less shrinkage enhancing good dimension precision.
A518
A518 die casting aluminum alloys aluminum has 7.5-8.5% magnesium, <0.35% silicon, 0.1% copper and other trace elements. The low silicon level results in its poor fluidity and castability which is in contrast to other aluminum alloys with higher silicon levels. However, due to its level of magnesium, A518 has a very strong corrosion resistance level without degrading in harsh environments, adequate strength, and ductility.
Other properties of A518 are excellent machinability, light weight (density is around 2.66g/cm3), and moderate electrical and thermal conductivity (96.2W/m–k). Also, it is usually used in elements with complex designs because they have to undergo deformation without cracking. It is widely used in the marine industry to produce boat hulls and other marine equipment, and in the automotive industry for fuel tanks, lightweight designs, architectural components, and lots more.
Zinc Die Casting Alloys
Zinc die casting alloys have a composition of zinc (in high amounts), together with aluminum, magnesium, and sometimes copper. Zinc alloys are peculiar due to their high strength, impressive corrosion resistance, low melting point, and their hardness (presence of copper). Zinc alloys are also cost-effective because of their production speed. The price of these alloys ranges from US$ 1.0- US$ 5.0 per piece. Note that this price is depending on its size.Let’s explore the following zinc die casting alloys used in the production of metal parts and other components.
Zamak 2
The Zamak 2 alloy mainly consists of zinc (96.6%), aluminum, magnesium (0.02-0.06%), and copper (2.5-3.0%). Its copper content appears to be more compared to other members of the Zamak family. Thus, it possesses the highest strength, and hardness (yet easily machinable) with its mechanical properties, but exhibits less castability, fluidity, and corrosion resistance.
Its less fluid nature does not hinder it from producing high-quality, dimensionally accurate parts with post-casting processes such as polishing, and anodizing done to it. Its wear resistance property and other benefits make it ideal for manufacturing small components like gears, locks, and latches for automobiles.
Zamak 3
Zamak 3 die casting alloys comprises of aluminum (4%), and zinc (96%) with about 0.03% copper. Zamak 3 offers good fluidity making it castable and enhancing its application in the manufacture of complex shapes and thin-walled designs. This alloy has good resilience to vibration, especially at high temperatures. The surface of the alloy can also be modified by painting or treating it with good materials e.g. powder coating. The presence of aluminum and magnesium makes it corrosion-resistant. Zamak 3 is used in applications like furniture fittings, hardware, automotive parts, and electrical components that have good thermal and electrical stability.
Zamak 4
The Zamak 4 die casting metal is frequently used when compared to Zamak 3 or 5. The copper content in Zamak 4 (0.7-0.9%), is relatively higher than that of Zamak 3, increasing its mechanical properties like tensile strength and hardness. This makes the alloy good for applications that require proper mechanical performance. The copper content reduces its ductility and corrosion-resistance. Thus, it may require external coatings or treatment to maintain its form in harsh conditions.
Zamak 4 also has moderate thermal and electrical conductivity (a little lower than Zamak 3). Hence, it may not be suitable for applications where heat transfer and high temperatures are major concerns. Common applications of Zamak 4 are in the automotive industry (gear housing, brackets, and chips), industrial tools, and the production of levers and pulleys.
Zamak 5
Similar to Zamak 3, they have copper content of about ≤0.15% which enhances its mechanical properties like strength, and hardness over Zamak 3. This reduces its ductility making the material less stretchy and unable to undergo significant deformation. Zamak 5 can be powder coated, painted, electroplated, and treated with materials to improve its aesthetics and reduce corrosive tendencies.
This die casting metal has good machinability as well as a good surface finish without defects. It is used in the production of door locks, windows, power housings, and other aesthetically appealing equipment like toys.
Zamak 7
Zamak 7; a high-purity alloy consists of 3.8-4.3% aluminum, 0.25% copper, 0.005-0.02% magnesium, and of course, zinc in higher amounts. Nickel content in Zamak 7 reduces the impurities while it prevents intergranular corrosion due to its effect on the microstructure. Thus, nickel helps to improves its corrosion resistance.
It can attenuate vibration which also enhances good performance and longevity. The low content of magnesium helps to improve the fluidity and ductility of Zamak 7 which makes casting of complex and intricate designs easy. Its applications include decorative or aesthetic items, toys, hardware fixtures, etc.
ZA8
ZA8 contains about 91-92% zinc, and 8-8.8% aluminum. The increased aluminum content over others gives it its lightweight and improved properties generally. It is a very light alloy requiring a hot chamber die casting process. ZA8 has a very high tensile strength (372MPa), higher than most of the other zinc alloys while yielding a high strength-to-weight ratio. It is also harder than most Zamak die casting alloys which gives it improved wear resistance, machinability, and durability.
Also, it can be plated or coated to increase its corrosion resistance and surface finishing properties. It is applicable in decorative tools, electrical components for switch gears, connectors, hardware like door handles, locks, and even various industrial machinery.
EZAC
The major contents of the EZAC zinc die casting alloys are zinc, aluminum, and copper. These components give it high strength, hardness (120-140HB), and improved creep resistance at elevated temperatures over other zinc alloys, while enhancing the longevity of the die casting products. EZAC is suitable for hot chamber die casting due to its low melting temperature.
EZAC gives a yield strength of about 396 MPa which is greater than that of any other hot chamber zinc die alloy allowing its products to withstand high loads before deformation. Like other zinc alloys, it is highly fluid when casting which facilitates the production of thin-walled designs. Although they are more expensive than other zinc alloys, the performance and longevity of their components are top-notch. They are used in the production of electrical components like connectors, heat sinks, gear components, pulleys, and aerospace and medical devices.
ZA27
The ZA27 die casting metal consists of mainly 27% aluminum, zinc (74%), and 2.2% copper. Its aluminum content is way higher than any other in the ZA family contributing to a higher strength-to-weight ratio. As a result of its high yield and tensile strength, low density, and high melting point making, ZA27 requires cold chamber die casting.
ZA27 has good fluidity and great castability. Its hardness and strength improve its wear resistance making it ideal for products subject to friction like gears, and bearings. The cast products usually maintain their shape and size under any temperature or stress but it may require being extra careful during casting. Lastly, ZA27 is easily machinable. This makes it good for post-casting treatment or operations such as drilling, milling, and coating without any damage.
Magnesium Die Casting Alloys
Magnesium is known for its lightness. It is 33% and 75% lighter than aluminum and steel respectively. This feature makes its products valued for their lightweight and suitable for applications requiring less weight in aerospace and automotive industries. Magnesium die casting alloys are also known for hot chamber die casting, and their efficient machinable characteristics offer good castability and shielding properties.
The price of magnesium die casting alloys ranges from US$59- US$259 depending on the size and number of pieces. The following are common die casting magnesium alloys.
AZ91D
AZ91D die casting material belongs to the AZ family of magnesium alloys and it is the most widely used of all magnesium alloys. It contains approximately 9% aluminum, 1% zinc, and other trace elements with magnesium contributing to its higher percentage. AZ91D is known for its top-notch combination of mechanical properties, good corrosion resistance, and castability as it flows smoothly when in molten state. Its tensile strength is around 230MPa making it fit for applications that must endure moderate stress.
Its aluminum content makes it a great corrosion-resistant alloy compared to others of its kind. Additional surface treatment can be applied to increase its corrosion resistance. It exhibits about 72W/m–k thermal conductivity adding to its benefits and making it suitable for components that require adequate heat transfer.
This alloy can be used in the production of transmission housing, and aerospace components (for components like seat frames), it is used in housings and enclosures, sporting goods, and lots more.
AZ81
The AZ81 magnesium die casting alloys are majorly composed of magnesium and 0.5-1.0% zinc. This alloy is very similar to AZ91D as its properties are just slightly lower than its. For instance, its tensile strength is around 220MPa and it offers optimal castability with more advantages for complex shapes. Also, it offers moderate corrosion resistance and needs additional coating.
AZ81 is less expensive than the AZ91D and it is used for housings in electronic devices, engine parts, transmission houses, and many more applications.
AM60B
Magnesium AM60B die casting alloys appear to be a modification of AM50A. It is commonly known for its outstanding ductility, high energy absorption, high strength, and castability. Its nominal components are aluminum (5.8-6.4%), zinc (0.2%) together with magnesium. It is used for the production of seat frames, laptop cases, panels, and bicycle frames.
AM60B offers tensile and yield strength of about 230MPa and 120-130MPa respectively, connoting its ability to carry a reasonable load before it deforms. Its manganese content of about 0.35% prevents corrosion and removes iron impurities. This alloy is very good for high-pressure die casting, it is very fluid and it cools rapidly, producing amazing structures. It can be coated, painted, and anodized.
AM50A
AM50A diecast material accounts for its magnesium content and its other nominal components to be 4.7-5.3% aluminum with 0.2% zinc, manganese, and other trace elements. These components are slightly lower than that of the AM60B. Its tensile strength falls around 200-210MPa making it also ductile and flexible, suitable for components that may require deformation. AM50A is good for thin-walled casting as it flows better than AM60B. Like AM60B, it is mostly processed using high-pressure die casting.
AM20
The AM20 alloy contains primarily aluminum (2%) and manganese (0.3%). AM20 has moderate impact strength and extremely low tensile strength. It is lighter and more ductile than other magnesium alloys containing aluminum. As already established, manganese improves it’s corrosion resistance property. AM50A and AM60B are higher modifications of AM20. The creep resistance of AM20 is not so high and not ideal for high-stress or temperature applications. It is cost-effective for components that do not require so much strength.
AS41B
The AS41B contains both aluminum (4%) and silicon (1%) as its primary alloy elements. The presence of silicon improves its creep and wear resistance making it appropriate for high-temperature environments and fit for applications like powertrain elements, and transmission housings. The alloy has higher strength, and lower ductility when compared to AM20, but the silicon content gives it better corrosion resistance, although vulnerable in a high chloride environment.
Conclusion
This article discussed what is die casting metal, the various die casting metals, and vital points to consider while selecting aluminum, zinc, and magnesium die casting alloys for your products. This information will help you choose the best metal for whatever cast you would like to produce. Raidy Mold has a reputation for manufacturing various die casting alloys and offering die casting services. Their services include consultation, sales, and delivery of alloys, cast parts, and die casting machines.Looking for the best die-cast service providers in the industry? Contact Raidy Mold today.
