Home page Solution The basic metal casting process

The basic metal casting process

There are many choices for manufacturing, but metal castings are the top form of manufacturing for its great benifits. However, not everyone understand how to carry metal casting clearly. Therefore, this article focuses on the basic metal casting process and termed related.

1. The basic metal casting process

The basic metal casting process involves creating a pattern and a mold, then pouring molten metal into the mold. You will then extract the solid metal casting and finish your piece. This process is customizable for different types of metal casting, along with shapes, sizes, and more.

metal-casting-process-1

Step 1: Create the pattern

Before you make your mold, you must create a pattern to determine the mold’s shape. The pattern can be a 3-dimensional model of your final cast. It may be shaped in wax, sand, plastic, or even wood. Some casters use molds made of plaster or silicone, which are materials that could not withstand a molten metal cast, but allow the caster to mass create wax multiples to use in expendable mold casting. When you are shaping your pattern, make sure you account for any anticipated shrinkage when the metal cools. Patterns may also be gated with sprues to allow the molten metal to flow into the mold.

Step 2: Make the mold

After you have created a pattern, it is time to make your mold. As we mentioned above, you may choose to make a reusable mold, which is typically made from metal, or a single-use mold, which may be made from sand, plaster, or ceramic shell. Each of these methods for making molds are optimized for different casting metals and various levels of pattern complexity. If you are working with a wax or plastic pattern, you can burn out the pattern inside of a kiln.

Step 3: Choose the metallic alloy

All metal castings are produced from either ferrous or non-ferrous alloys. Alloys are a mixture of elements that provide the best mechanical properties for the final cast’s use. Ferrous alloys include steel, malleable iron, and gray iron. Non-ferrous alloys that are most commonly used in casting are aluminum, bronze, and copper. If you are working with precious metals in a jewelry studio, you may work with silver, copper, gold, and platinum.

Step 4: Melt the alloy

Melting processes vary between alloys because each alloy will have a different melting temperature. Essentially, melting consists of placing the solid alloy in a crucible and heating it over an open flame or inside of a furnace.

Step 5: Pour into the mold

Pour the molten metal into the mold cavity. If it is a small casting, you may simply pour from the crucible where the metal was heated directly into the mold. A larger casting may require a small team to support heating the metal inside of a furnace, and transferring the metal into a larger crucible or ladle before being poured into the mold.

Make sure to follow all recommended safety guidance when pouring molten metal. Make sure you wear protective clothing, including natural fiber clothing, long pants and sleeves, insulated gloves, and safety goggles. Work in a well-ventilated space to avoid any risks from dangerous fumes. Make sure you have a chemical fire extinguisher nearby and keep your walkway between the furnace and the mold clear. Allow the mold to solidify before moving onto the next step.

Step 6: Remove the casting from the mold.

When the metal has cooled and solidified, you can remove it from the mold. If you cast into a single-use mold, you can break away the mold from the casting. If you used a plaster investment, you will want to quench the plaster in water after the metal has solidified. The water will help break away the mold. For reusable molds, you may use ejector pins to extract your casting.

Step 7: Finishing

File and polish your solid metal cast! This may involve cleaning your cast metal object, like scrubbing away excess mold material in water, breaking off the casting gates with clippers for small objects, or even an angle grinder for large pieces.

2. Advantages of Metal Castings Explained

Cost-Effective

Metal castings provide a more cost-effective option when it comes to low-volume manufacturing because of speed, low tooling costs, and ease of complex geometries.

Time-saving

Because metal castings are poured they require minimal tooling. Parts can be produced quickly and in minimal or mass quantities, making them a perfect option for low-volume manufacturing.

It also provides a simple process to produce parts that can be done without machining.

Complex Structures

Metal castings are a great choice for complex parts as they offer design flexibility as castings can be offered in a variety of sizes and shapes.

Another advantage of metal casting is you can achieve hollow sections or internal cavities with ease.

Casts can be exceedingly small or even incredibly large without compromising quality or their structure.

Even the most complex parts can be metal cast which may be more time-saving and cost effective than machined.

Product Quality

Metal castings offer high compressive strength and can produce thin walls without losing structural integrity.

Because metal castings are poured, you can quickly get consecutive quality cast parts. But not all Foundries have the knowledge and experience to produce exceptional quality metal castings.

The Surface Finish Of The Part

Although metal castings don’t automatically have finished surfaces metal castings can quickly be ground, smoothed, or painted to finish your part. Precise Cast provides in-house coating and paintings to expedite parts for our customers.

Recyclability of Metal

Many metal casting companies work with local recycling companies to help reduce waste. Also, most metal casting companies use less power consumption than other manufacturing options.