What kind of materials are used for castings?

7.1. Commonly used metals for gravity castings

A wide range of metals can be used for gravity casting, depending on the specific application and requirements. The specific alloy used for gravity casting will depend on factors such as the desired mechanical properties, casting process, and cost considerations.
Some of the most used metals for gravity casting include:

• Aluminum alloys: Aluminum is one of the most popular metals for gravity casting because of its low density, high strength, and excellent corrosion resistance. Aluminum alloys used in gravity casting include A356, A380, and ADC12.
• Copper alloys: Copper is a versatile metal with good thermal and electrical conductivity, making it suitable for a wide range of applications. Common copper alloys used in gravity casting include brass and bronze.
• Zinc alloys: Zinc is a low-cost metal with good castability and therefore suitable for large-volume production runs. Zinc alloys used in gravity casting include Zamak 3, Zamak 5, and ZA-8.
• Magnesium alloys: Magnesium is a lightweight metal with excellent strength-to-weight ratio and ideal for applications where weight is a critical factor. Magnesium alloys used in gravity casting include AZ91 and AM60.
• Iron alloys: Iron is a strong and durable metal with good machinability, making it suitable for a wide range of applications. Iron alloys used in gravity casting include gray iron, ductile iron, and malleable iron.

source:https://www.thomasnet.com/articles/custom-manufacturing-fabricating/alloy-die-casting/

7.2. What is the best composition of aluminum alloys for die castings?

The best composition of aluminum alloys for die castings depends on the specific application and performance requirements. Aluminum alloys are commonly used in die casting due to their excellent casting properties, including high fluidity, low melting point, and good corrosion resistance.
The most widespread aluminium casting alloys are the Al-Si alloys, particularly in automotive castings. For instance, the alloy A356 is used for engine blocks and cylinder heads. Aluminum alloys containing silicon (4%-13%) offer superior castability and a variety of properties. There are mainly eutectic alloys and hypoeutectic alloys (i.e. near eutectic compositions), though hypereutectic alloys can also be used in applications that require high strength, low thermal expansion, and durability.

Some examples of the commonly used aluminum casting alloys include:

1. A380. This is the most common aluminum alloy for die casting, thanks to its excellent casting properties and good mechanical properties. It contains approximately 8.5% silicon and 3.5% copper, which gives it good fluidity and casting properties.

2. A356. This alloy is known for its excellent castability and good weldability, pressure tightness, and good resistance to corrosion. It contains approximately 7% silicon, 0.45% magnesium, and 0.35% copper. This alloy is often used in aircraft structures and automotive engine controls.

3. A413. This alloy is known for its excellent pressure tightness and good resistance to hot cracking. It contains approximately 12% silicon and 1% copper, which gives it good casting properties and resistance to heat.

4. A360: This alloy is known for its good corrosion resistance and excellent dimensional stability. It contains approximately 8.5% silicon and 0.5% magnesium, which gives it good casting properties and resistance to heat.

5. ADC12. This alloy is also known as A383 and commonly used in automotive applications, thanks to its good mechanical properties and excellent corrosion resistance. It contains approximately 12% silicon, which gives it good casting properties and resistance to heat.

6. ALSi12. This alloy is a eutectic alloy that solidifies at 577 °C. It is known for its excellent corrosion resistance and good casting properties. It contains approximately 12% silicon and 1% magnesium, which gives it good casting properties and resistance to heat.

7.3. what are factors considered when Ming Ming designs the composites of aluminum alloys?

The design of aluminum alloy composites involves balancing several factors to achieve desired properties and performance characteristics. Some of the factors considered in designing the composites of aluminum alloys include:

1. Alloy composition. The choice of alloying elements in the aluminum alloy composite can significantly impact its mechanical, thermal, and chemical properties. Elements such as copper, magnesium, zinc, and silica can be added to aluminum to improve strength, corrosion resistance, and other properties.

2. Reinforcement type. The type of reinforcement added to the aluminum matrix can also affect the properties of the composite. Reinforcements can be in the form of fibers, particles, or whiskers, and may include materials such as carbon, ceramic, or metal.

3. Reinforcement content. The amount of reinforcement added to the aluminum matrix can influence the mechanical and physical properties of the composite. A higher volume fraction of reinforcement typically results in a stronger and stiffer composite but may also increase its weight.

4. Processing method. The method used to forge the aluminum alloy composite can affect its microstructure and properties. Different processing methods, such as powder metallurgy, casting, or extrusion, can be used to produce the composite with specific properties.

5. Environmental considerations. The properties of the composite must be considered in relation to the intended application, which may involve exposure to specific environmental factors, such as temperature, humidity, and chemical exposure.

Overall, the design of aluminum alloy composites involves balancing these factors to create a composite that meets the specific performance requirements of the intended application, while also considering factors such as cost and manufacturing feasibility.

7.4.Alloys used in Ming Ming’s gravity casting

As we supply high-quality castings for automobiles, we ensure that high-quality metals are added. The main materials used for our castings are aluminum alloys with little portions of other high-quality materials in the process. Since we produce gravity die castings, we require fluid alloys which can withstand freezing conditions in the dies.
Aluminum alloys used in Ming Ming’s foundries are near-eutectic alloys. The combination of the metals in the alloys has near melting and freezing points. They also possess excellent casting properties and good resistance to hot tearing. This is due to materials such as silica, magnesium, and iron in the alloy composition. The most important characteristic of alloys is good machinability as well as high resistance to chemical erosion.

Here we provide a brief overview of aluminum alloys used in Ming Ming’s foundries:

• Aluminum Alloy A356 has the chemical composition of AlSi7Mg0.3, which consists of aluminum, silica, and magnesium. It is suitable for lightweight automobile components.
• AC4B, which is reinforced by the fraction volume variations of Boron Carbide through the stir casting process.
• Al-Si-Mg casting alloy (AC4C-T6) is widely used due to its good mechanical properties and lightweight. It is highly workable and can be used for castings with complex geometries.
• EN AC 42100-ENAC-AlSi7Mg0.3 is an alloy specifically conforming to the European norm. This alloy has better tensile strength than the other alloys used in our foundries. It is used in producing high-quality lightweight spare parts.