ALSi12 alloys are primarily popular in the selective laser melting process. ALSi12 is an aluminum alloy made up of aluminum and 12% alloy. It features a high strength-to-weight ratio and has excellent corrosion resistance. For this reason, this metal is used mainly in the automotive and aerospace industries.
Another important detail that distinguishes the AlSi12 is that it is hypostatic. This implies that the silicon content, which is 12%, is below the eutectic point. Therefore, a primary aluminum phase is usually before the eutectic structure forms during solidification.
To learn more about the manufacturing process of AlSi12 die casting, read through this blog.
Properties of Alsi12 Alloy
Low Melting Point
AlSi12 has a melting point of 577 degrees Celsius. This implies that the metal needs less energy to melt, making it compatible with die casting; hence, it can be used to produce detailed parts.
Good Fluidity
The molten AlSi12 can flow easily and fill mold cavities during die-casting. Therefore, it is ideal for making components with complex geometries and those that require outstanding details.
High Strength
Thanks to the silicon content, the AlSi12 has a high strength. This makes it hard to wear, and it is also very stiff. The strength also makes it ideal for demanding applications. When used, you are assured to get a highly durable part.
Good Corrosion Resistance
Another significant property of AlSi12 alloy is its good corrosion resistance because of its aluminum-silicon composition. Therefore, it offers protection against wear and tear, so you can have the part for a long time without requiring routine maintenance.
Good Machinability
The silicon in AlSi12 enhances its machinability, allowing easier cutting, drilling, and shaping. This way, you end with smooth finishes, making it ideal for efficiently producing intricate components.
Benefits of Alsi12 Alloy
As seen, AlSi12 has very desirable properties. For this reason, it is often the go-to- option for various applications. Here are some of them. Some of the significant benefits of AlSi12 alloy include the following:
- AlSi12 is lightweight – Therefore, it is ideal for producing weight-critical items. It is often used in the automotive and aerospace industries. Weight reduction in the components in these industries impacts the fuel efficiency and performance of the machines.
- The sturdinessof AlSi12 makes it ideal for use in high-stress applications. This includes making automotive components, aerospace parts, industrial machinery, and high-performance sports equipment.
- AlSi12 is corrosion-resistant– Therefore, it can serve long in harsh conditions such as marine and acidic environments. It is ideal for making outdoor machinery and chemical equipment.
- Finally, you can easily customize the AlSi12 parts, and the excellent machinability of this alloy allows for the precise fabrication of detailed and complex components.
Limitations of AlSi12 Alloy
Despite the many advantages of using AlSi12 alloy, especially in the aerospace and automotive industries, it still has several drawbacks. Here are some of them:
- High Silicon Content: AlSi12 alloy contains 12% silicon, which is considered incredibly high. This silicon content can make welding challenging as the formed part can have brittle phases.
- Not as Strong: We cannot compare the strength of AlSi12 alloy to other aluminum alloys. This alloy, in particular, features a low tensile strength. Therefore, it might not be suitable for making parts that need extra sturdy to function.
- Thermal Expansion: AlSi12 is a combination of two different elements. Now, each has its thermal expansion, which can cause internal stresses to the parts as they heat or cool.
- Susceptible to Wear and Tear: Another limitation of AlSi12 alloy is that it is susceptible to wear and tear due to its high silicon content. This, in return, can reduce the lifespan of the alloy in specific applications.
Technology to Influence Mechanical Properties of AlSi12 Alloy
The following technologies are capable of influencing the mechanical properties of AlSi12 Alloy. We have further explained how each technology affects the alloy:
Selective Laser Melting (SLM)
AlSi12 alloy is the most widely utilized material for selective laser melting. This additive manufacturing process uses a laser to melt metal powder. The laser moves over the powder, creating a solid item one layer at a time.
During Selective Laser Melting, the AlSi12 alloy undergoes rapid melting and solidification cycles. These cycles allow for grain refinement, which is vital for getting a strong alloy.
The SLM process allows for the production of almost entirely dense materials. This is vital in reducing porosity, therefore improving the mechanical properties of the alloy.
The SLM process involves making the AlSi12 alloy using the layer-by-layer process. This can create direction-dependent mechanical properties. This property can differ along and perpendicular to the building direction.
Electronic Beam Melting (EBM)
This additive manufacturing process uses an electron beam to melt metal powder. Typically, the electron beam focuses on a small area of the powder bed. It then melts the metal, creating a solid object layer by layer.
Electronic Beam Melting positively influences the mechanical properties of AlSi12 alloy because it occurs in a vacuum. This helps reduce oxidation and contamination of the alloy.
Also, an Electron Beam results in a higher energy density final product. In this case, the electron beam acts as a super-powerful flashlight that shines brighter than regular flashlights. The fact that it is pretty bright ensures that the tiny particles of the alloy are melted together well.
Electronic Beam Melting causes coarse microstructure. This determines the elasticity and strength of the alloy.
Laser-Engineered Net Shaping (LES)
A layer with a power range of about 4.5kW is used in this manufacturing process to manufacture AlSi12 alloy. The used travel speed is 90 to 180mm/min, a hatch distance of 0.1mm, a spot size of 150m, and a 0.1mm layer thickness. Here, the laser is used to melt the metal powder, creating a solid object layer by layer, which is then machined to form the desired shape.
Laser Engineered Net Shaping involves rapid solidification, which results in finer microstructures. This ensures that the parts produced have better mechanical properties.
During the LENs printing process, secondary materials are added. These materials can be used to change the properties of AlSi12 alloy.
The laser-engineered net shaping process can be adjusted as it happens. This way, you can control how quickly the alloy cools down. This will, in return, affect the inner structure and strength of the final product.
Cold Spray Additive Manufacturing
This manufacturing process is most suitable when dealing with thick metallic coatings. When manufacturing AlSi12 alloy, the fine aluminum-silicon powder is sprayed at high velocities. Once there is an impact, the particles bond and build the AlSi12 layers without melting, forming the desired structure.
During the cold spray additive manufacturing process, no melting takes place. Therefore, this reduces the possibility of thermal stresses and defects such as porosity
The cold spray additive manufacturing process involves a high-velocity impact of particles, which can cause work hardening at the deposited surface. Consequently, this can improve the hardness and strength of the par.t
Additionally, cold spray additive manufacturing incorporates mechanical interlocking and deformation bonding mechanisms. This can cause different mechanical properties, unlike when using traditional fusion-based additive manufacturing methods.
Which Mechanical Properties of AlSi12 Alloy are Affected?
The various technologies above influence the mechanical properties of the alloy. Here are some of the mechanical properties of AlSi12 alloy which are affected:
- Tensile strength – Some technologies affect the ability of the alloy to resist breaking when pulled—also, the tensile strength can improve when the alloy’s microstructure is refined
- The technologies can also affect the thermal expansion of the alloy
- How well the alloy can withstand long-term stress at high temperatures can also be affected
- Also, the impact toughness of the alloy can be affected due to the distribution of silicon and porosity
- The alloy’s resistance to breakage under repeated loads is also affected, but this can vary depending on the internal defects and microstructure
- The alloy’s yield strength, which determines the point at which the alloy can start to deform, is also affected
Conclusion
AlSi12 alloy has excellent properties, making it a go-to option for the automotive and aerospace industries. The primary manufacturing process for this alloy is Selective Laser Melting, which ensures precision, durability, and efficient production. With advancements from leading die-cast manufacturers in China like Sunrise Metal, you can be sure to make the right choice when using AlSi12 alloy for die-casting. Talk to us today, and we will solve all your die-casting needs.