Aluminum die casting is a process where we use reusable molds and molten aluminum to produce complex parts. The alloys are shaped by forcing molten Aluminum under high-pressure into the dies cavity.
Machines Used in Aluminum Die Casting Process
Two types of machines are widely used in this process, hot chamber die casting and cold chamber die casting. The procedure of them doesn’t differ much from one another. However, depending on the alloys and parts, the right machines are chosen.
Hot Chamber Die Casting: Hot chamber machines are used for alloys with low melting temperatures, such as zinc, tin, and lead.
This machine is most suitable for materials that have a low melting point. The hot chamber is not suitable for materials with a higher melting point because it would damage the machine’s pump.
Cold Chamber Die Casting: These machines are better for metals that have a high melting point like aluminum, magnesium, etc. The process of both machines is quite similar. Although with cold chamber machines there is no chance of damaging the pump with high temperature.
The Actual Process:
- Set up mold: This is the first step of starting the die casting process. First, We need to check if the mold is made perfectly according to the design. Cleaning the mold before work is necessary as well.
Then we install or set up the mold inside the machine and make sure they’re closed and clamped with appropriate force. The force should be strong enough to stick both halves of the mold, so it doesn’t open during the process.
- Die casting parameter setting: In this stage, we set up the parameters of the machine. The accurate parameters allow the machine to maintain an accurate measurement throughout the process.
- First article inspection: After the sample is approved and the mass production has begun. We randomly chose a set of parts and inspect it. The name may apply that only the first produced parts are taken into inspection, but that’s not quite right. Parts can be taken randomly from any initial production and taken into an inspection to see if there are any defects in the mass production parts.This is to ensure that the final products are error-free and if there are any errors to be found, the error is fixed immediately and the production gets restarted.
- Lubrication: Lubricates helps the parts to be ejected from the dies. Although lubrication is not required before every cycle, it’s advised to apply lubrication in the beginning and after a couple of cycles to make the process smoother.
- Clamping: Clamping enables the die halves to be closed tightly. Because the die halves aren’t closed tight and is loose, there will be defects in the final products. Clamping should be ensured that it leaves no space and closed the die halves tightly with a strong force.
- Injecting the molten metal: In this stage, the molten metal which is then in the furnace at a controlled temperature, moved into a shot chamber. Which allows it to be easily injected into the die.Once the molten metal is in the shot chamber, it gets injected with an injection ram into die for solidifying. The pressure holds it into the die cavity and it’s maintained throughout the process.
- Cooling process: The molten metal starts to cool down when it enters the die cavity and begins solidification. Which enables it to take into the shape of the dies. The die halves cannot be opened until the cooling is complete and the molten metal turns into solid metal.The cooling time can be longer for parts with thicker walls or complex design and vice versa.
- Ejection: When the parts are cooled off sufficiently we can open up the die halves. When it’s opened, the ejection system pushes the casting out of the die cavity. And this how the parts are removed from the machine. After that, the die halves are ready for the next cycle.
- Edging or Trimming: With the die casting process, there is always excess material attached to the parts. We need to cut it and make them smooth before final use or delivery.
- Last article inspection: Almost similar to the first article inspection, the only difference is that it’s conducted on the last batch of final products. To ensure that the right quality and error-free products are being delivered to the buyers.
Why Aluminum alloys are the best metal for die casting?
Aluminum is not the only option for die casting. However, it’s the most used alloys in this process. There are many reasons why aluminum die casting products are widely popular around the world. Let’s see some of the reasons below:
- Outstanding thermal and electrical conductivity
- The metal is very lightweight and corrosion-resistant.
- Fair densitiy
- Has high dimensional stability and ability to produce complex design parts
Other than that, there are many grades of aluminum metal that are suitable for many different projects. All these reasons make aluminum the best alloy for die casting.
This process is vastly used in marine, aerospace, automotive, medical, general and many other industries as well.
Aluminum Die casting vs steel die casting
Both aluminum and steel are widely used for the die casting process. Let’s compare them head to head and find out which one is the best alloy for you.
If we consider the cost between these two, we have to keep in mind that the cost of these materials can go up and down at any time in the global market. However, in general, aluminum costs less than steel alloys. So if you have a low budget, you might want to go with aluminum.
Secondly, if you need your parts to be higher heat resistant, steel might be a great option for you. Because this two aluminum has low heat resistance. Which allows it to have a low melting point. It also allows it to have more castability.
Third, if you need your parts to be machined after removing from the mold. Steel can be a great option for you. Because of their higher strength, it has better machinability compared to other metals.
Fourth, Two of the great factors to consider when choosing the metal is that weight and strength. Often we want both in our parts, however, between aluminum and steel, each one has its unique advantages. For instance, steel has higher strength and more corrosion resistant compared to aluminum. On the other hand, aluminum is a very lightweight material compared to other alternatives and the weight to size ratios is significantly better from other metals as well.
These are some of the basic differences between both the alloys. However, before choosing you need to consider your design and requirements to find out how you will be most benefited from this process. We also suggest that you consult with your manufacturer before making a decision.
Benefits of Aluminum Die-casting process
This process is widely popular among many industries worldwide today. The reason behind this is simple, companies want products that meet their requirements precisely. And there are not a lot of options that can meet the requirements as aluminum die casting can.
Industries like marine and medical need their products to be very accurate and identical to their design. And with this process, you can get 100% accurate products according to the design. The reason is that the process is completely automatic and operated by a computer. There is no scope for errors and mistakes. All the parts and products manufactured from this are identical to each other.
On the other hand, companies like automotive and aerospace want their products to be lightweight and fit with their other parts accurately. Fortunately, with aluminum alloys, the final products are very lightweight and suitable for any industry. But the lightweight nature of aluminum doesn’t reduce it’s quality at all.
Other than that, it’s a corrosion-resistant ability, weight strength ratio is very high compared to other processes or alloys. Which makes them even more favorite among buyers.
One other important factor we need to consider is that, if you’re ordering goods for your company, you always want two things, first- low cost, and second- low lead time.
And with this process, you can have both opportunities. Compared to metal die casting or other alternatives aluminum die casting is relatively very fast to manufacture and the cost is very minimal.
If you’re associated with an OEM/ODM company and need a bulk amount of customized products, aluminum dies casting can be the best choice for your company.
The fast production, multiple finishing, and simple assembly make it even more acceptable and preferred process to manufacture bulk amounts of parts for companies like yours.
What are the alternatives to the die casting process?
As we know the die casting process has taken over the world, however, this is not the only way of casting metals. Sand casting and investment casting is also around from the beginning. Now we’ll compare these options and see why die casting has become so popular.
Die casting vs Sand casting vs investment casting
As you already know, in die casting we inject the molten metal into a die with high pressure. The die is made according to the product design and the final product takes the shape of the die and becomes identical to the actual design of the product. The process is way faster and automated. The best part about die casting is that we can use the same die many times. Which reduces the manpower and cost of creating a new die every time for each part.
On the other hand, in sand casting, first, a shape is created with the sand, and the molten metal is directly poured into it. When the metal cools off the sand is removed from the metal and the parts are extracted. The problem with this casting method is that you need to make a sand shape for each and every part. And the process is entirely manual. So it needs a lot of time and energy if you need a bulk amount of parts.
For one or two parts you can use this method. Another significant setback of this method is that you need to do a high amount of machining, finishing onto the liquid ceramic. Now what happens is that the ceramic gets attached to the wax prototype or shape, and because of the heat of the ceramic, the wax melts down and comes out of the ceramic shell.
Now the ceramic takes the exact shape of the wax prototype, and when it does, just like sand casting, molten metal is poured into the ceramic shape. After the molten metal is cooled off and it takes the shape of the ceramic prototype, the ceramic mold is broken down leaving the perfectly shaped casted metal.
As you can see the process is very manual and long. So if you do this process, it can take even more time than the sand casting method. This is not a practical method for a large volume of orders.
Finally, OEM?ODM companies need their product with fast lead time and an absolute accuracy and precision. When we use manual processes like sand casting or investment casting, maintaining a similar quality and measurement is extremely difficult. On top of that sand casting and investment casting both take a lot of time to be done.
For these reasons, buyers and manufacturers need to rely on die casting methods, to provide accurate measurement and higher quality casting parts in a very short time. Because of the automated process, this becomes very easy and fast with the help of the right tools and machines.
In the past, a handful of industries like automotive or medical needed customized and complex parts to be manufactured, But now the time has changed, and started from telecommunication industries to the entertainment industry, all need customized parts and products for them. This is where the aluminum die casting process comes in handy. With the help of aluminum alloys and die casting methods, manufacturers can produce bulk amounts of highly complex products within a very short lead time and lower cost. The best part of aluminum die casting is that the final products are 100% accurate to the design.
If you’re an OEM/ODM company and need a bulk amount of parts to be produced, the aluminum dies casting process can be your best option. But still, according to your design and requirements, this might change. I suggest you get in touch with Sunrise-Metal to have a better idea of what you should begin and how we can help you.