According to an apocryphal story that may or may not be true, Napoleon III had a set of aluminum cutlery he brought out only for special guests he wanted to impress. His less-favored guests had to make do with plain old silver or gold cutlery, silver and even gold being less impressive than aluminum at that point.
True or not, it is a fact that aluminum has gone from being a very expensive material to now being so ubiquitous that we use it for packaging soft drinks.
If you think back to the old Periodic Chart of the Elements, you may remember that Aluminum is No. 13, and uses the symbol Al. Did you know that aluminum is the most abundant of all the metallic elements in the Earth’s crust? This abundance gives it a huge advantage, and only iron is used more in manufacturing.
Aluminum is strong, light-weight, inexpensive and easy to shape, which is why aluminum casting has become a mainstay in countless industries. Foundries cast aluminum for household goods, the automotive and aerospace industries and thousands of other things. You probably don’t realize how many cast aluminum items are in your home right now.
Aluminum is today favored not for spoons and forks but for nearly everything else. It’s a practically ideal material for many reasons. No matter where you are or what you’re doing right now, there’s a very good chance that several cast aluminum items are near you. If you’re at your desk, perhaps the drawer pulls or part of your desk lamp are made of cast aluminum. If you’re riding in a car, many of the automobile components are made of cast aluminum. If you’re in your kitchen, you likely have many aluminum pots and pans that were manufactured using a cast aluminum process. If you’re relaxing in your backyard, there’s a good chance your outdoor furniture was manufactured using cast aluminum. It is everywhere.
Aluminum casting is one of the most common manufacturing processes because it offers many advantages. First, a word about aluminum molds / moulds. You may have seen both these words and may wonder what the difference is. The answer is, there is no difference. The standard American spelling is “mold” but the standard British spelling is “mould,” so if you’re reading something written for an international audience you may see either spelling used. Molds may be made of a variety of different materials, which will be explained in greater detail below.
At Cast Technologies, we understand the advantages and disadvantages of each industrial process. Our generations of experience help us to recommend the right process for your product. Some methods are cheaper but may require more machining after the item is removed from the mold. Other methods produce parts that meet very exacting tolerances.
There’s also a question of the size of the production run. If you need to make a large number of an item, you may prefer to devote more resources to a reusable mold. However, if you’re planning a very small production run, it may make more sense to use a simple one-use mold.
Here are some of the common methods foundries use to cast aluminum products:
In this process, molten aluminum is poured into a cavity made in what is known as “green sand.” The term “green” has nothing to do with the color of the sand used. The molding mixture consists of uncured sand, clay and water mixed together. Sometimes, other additives are used in the mixture to give it specific properties as needed for the component being manufactured. When people think of sand casting, green sand casting is the process they usually envision. It’s an ancient technology that goes back thousands of years.
Aluminum die casting is often used in automotive, electrical and other industrial products. The process allows for the creation of very complex and precise castings. The aluminum comes out with a smooth surface and tight tolerances, and in most cases will require little or no machining.
This is an efficient and inexpensive method of casting. It includes green sand casting, as explained above, and air set casting, which entails a hardened sand mold.
Molten aluminum is poured into a mold made of resin-covered sand.
In this process, a ceramic mold is formed around wax, which melts once the mold is fired. After the wax has melted away, the molten aluminum is poured in. This process allows for a high degree of precision.
Yet another method for casting aluminum is the plaster mold. These molds are made by pouring a plaster slurry around a wax form. As in a ceramic mold, the wax pattern melts away, making room for the molten aluminum. Both plaster molding and ceramic molding are known as “lost wax casting.”
There are multiple methods of casting aluminum, but they all have advantages. Aluminum casting is cost-effective and versatile, and creates parts that are strong and resistant to corrosion. Depending on what process is chosen, castings can make tiny, delicate components for jewelry or huge engine blocks weighing hundreds of pounds.
The ease of aluminum casting lends these items to a large variety of uses. They include:
Cast Technologies is a third-generation family-owned business that was founded in 1887. An expert in aluminum casting, this foundry also casts brass, bronze and more than 33 other alloys. Cast Technologies is the largest brass/bronze sand foundry in Illinois. We offer high-quality casting, machining, assemblies and related services. Contact us today and let’s talk about what we can do for you.