Aluminum casting is the process in which liquid aluminum alloy is poured into a mold to get the precise shape of the mold or the frame. After oxygen and silicon, aluminum is the third most vital metal to look up to. Due to aluminum’s amazing properties and how cost-efficient and eco-friendly it is, aluminum has been chosen as the casting metal. After it had become the chosen metal, its popularity increased the extraction of the metal by 40% of its annual extraction. In this article, we will be talking about what aluminum casting is in detail, the types of aluminum casting done in recent years, and the distinguishing those processes ad discussing their pros and cons for better and clearer understanding. Let’s get into the guidebook of aluminum casting.
What is aluminum casting?
Aluminum casting is a process of getting the exact structure and specification of a tool or machinery by a cheaper and more efficient metal than the costlier and hard-to-maintain one by which the actual tool has been formed. Basically, aluminum casting is the best alternative to the actual expensive metal. As industries or manufacturers look for metal that is cheap yet has a great specification. So, aluminum casting is the best alternative of all. In this process, any liquid aluminum alloy is poured into the mold or frame, in order to get the exact shape of the mold which is the replicated shape of the real tool.
Aluminum casting processes and their advantages
There are different processes by which aluminum alloy replicas can be produced of the original structure. In all of the processes, the main ingredient is an aluminum alloy but the casting mold, structure or frame is different. The pressure or style of pouring the alloy into the mold is different. The finished product will look different and the extraction of the replicated structure will be different as well. Each of the casting processes is different and they depend on the product quality and its action at different stages. To get an overview of all these processes, one needs to have knowledge of all the processes briefly. Sunrise metal has this unique facility of asking the customer as to which process they want their machinery to be made of. This facility makes the company a little different from other companies. They are customer-centric and keep them as their first priority. Let’s focus on some of the aluminum casting processes:
Permanent mold casting
This is one of the costliest processes. It is because the mold that is being used in this process will be a permanent one, and for that, one needs to have strong metal like steel or iron. The mold can be used for a longer period of time. This will be a lifetime investment as the mold will not be damaged even after multiple sets of work and thus can be reused. In this, the liquid alloy will be poured into the two halves of the mold. One part will be airtight which will provide high pressure for the liquid alloy to get into the structure while the other half of the mold will provide low pressure for the liquid alloy metal to pour in. Once the alloy gets settled down give time for solidification. Right after it gets solidified, take out the newly formed aluminum structure. The final products that come out by the end of this process have a high definition of their finishing.
Sand casting
In this process, a reusable mold is used which will be stuffed with sand in order to give it the shape of the actual metal. The length of the mold is taken one size bigger as it will get shrinked down during the cooling process. The pattern is included with risers, the molten metal gets poured into the mold and the hot aluminum feeds the casting during solidification to prevent any porosity during solidification. Sand has the property to maintain the shape of the structure by holding the weight and the strength and resistance to interacting with the liquid aluminum alloy. This process is cost-efficient and can do the bulk of work at a time.
Die casting
The process of die-casting sounds much like permanent mold casting. The very first difference is not the use of reusable molds. Also, here the molten metal is pushed into the mold with high pressure which in turn leaves back some air pockets which makes the end product less effective as compared to permanent mold casting. Here, the mold doesn’t take much money to design so it can be called cost-efficient. and this process can be used to build high-volume structures. They have a superior surface finish.
Comparison among the casting processes
The table below will help to compare the advantages of the method:
| Cost of tool | Surface finish | Labor cost | volume | Typical tolerance in in. | |
| Permanent mold casting | higher | good | Low | average | +/- 0.01-0.03 |
| Sand casting | low | Average | low | Low to high | +/- 1.03-0.06 |
| Die casting | highest | outstanding | low | Very high | +/- .01-0.015 |
*The typical tolerance range has been taken from different sources.
Summary
Aluminum is chosen for casting because of its credibility as a metal. There are different casting processes and all those depend on the mold that they use, the temperature or pressure with which the molten metal is poured in, and the quality of the molten metal. Industries look for those who make bulk orders and are cost-efficient as well. The process should have a good mold and capacity to produce multiple orders in a very small span of time.