Investment casting is a foreign word for most of us. Many of us might be confused about this particular word, Investment casting, as not much is known. Investment in the current world has to do everything with business.
But does that mean investment casting also has anything to do with business?
A brief idea about investment casting by breaking down the whole world would be: investing your hard-earned income into an object made by pouring molten metal. Quite challenging, isn’t it?!
Maybe the assumption about investment casting should be left behind – a piece of excellent advice for life.
Now, let us leave all the assumptions behind and get into businesses. This article is about investment casting in-depth and clearly. So without further a due, we shall get started.
What is Investment Casting?
The dictionary definition defines Investment casting as a technique it makes accurate and small castings within refractory alloys. For this, they are using a form of mold around a pattern of wax-like material, and those are going to be removed by melting.
There is another historical meaning of the word invest, which means surround. The process surrounds the pattern with a refractory material to make a mold. Then into the mold, the molten substance is cast.
Hence its name, Investment casting. Makes sense! And not even an ounce close to our oh-so-smart assumption.
So Investment casting is also called The Lost- wax casting. It is one of the oldest lost-wax casting used in the ancient world and, fortunately, a technique the modern world has excellent knowledge about.
Ancestors from different cultures have used this technique in various forms for the past 5000 years, a very long time. Beeswax was used to form patterns essential for the casting process 5000 years ago.
Now, in the modern world, refractory materials, more advanced waxes, and specialist alloys are used for making patterns.
Investment casting is quite a valuable procedure for this process, and it can produce objects and components with high accuracy, repeatability, versatility, and integrity in various types of metals.
What is Investment Casting Used For?
Investment casting is used to make complex-shaped, accurate components that require tighter tolerance, thinner walls, and a better surface finish. Investment casting has limitless uses and is mainly used when a small production volume is required.
As in when about 0-10,000 pieces are required. Due to its versatility, investment casting is highly used in the aerospace, power generation, firearm, automotive and military industries.
Investment Casting Process
The most popular technique out there has eight steps.
Creation: Creating the pattern or the die of the desired workpiece is the first and foremost step in the process. And this pattern is made out of wax.
Mounting: After the creation steps, the wax design will be mounted, creating multiple wax designs and attaching them to the gate device. The gate device is the place where all the metal and other types of materials are going to be poured, and then it can create our needed workpieces.
Tree Assembly: Tree Assembly, a.k.a a fancy word to represent the step where the mounting of the wax pattern on the gate is completed. The step got this name because the individual work pattern is essentially a branch, and the workpiece comes to an end once the process is finalized.
Shell Moulding: After the process of Tree Assembly, the next step will be adding shelled casting all around it. Initially, the tree is going to be dipped in a ceramic slurry. And as the next step, the same is going to be dipped through a fine sand stucco.
These two steps will be carried out multiple times until the mold is thick enough to handle casting stresses.
Wax Removal: The wax needs to be removed first for the desired material to be poured into the newly shelled molds and is usually done by heating the wax in an oven. Steam can also be used.
The mold is then placed upside down for the liquid wax to flow out and reused to create the new wax pattern.
Mold Casting: After removing the wax, we can see there are open spaces from our shelled casting and it will be shown from a pattern of a formal wax. A liquid material or a metal that has been molted can be poured again into this casting.
The material shall remain in the casting until thoroughly cooled and solidified.
Removing the Casting of the Shell: We can use a hammer in order to remove this casting. The original tree is left at the end after removing the shelled cast. Finished workpieces will be seen attached to this tree.
The attached workpieces are carefully cut off the tree after removing the casting.
Finishing Procedures: The imperfection in the workpiece will be checked. If by any chance, you will find them, they will be instantly discarded, and the material used here is going to be recycled.
Different finishing methods will be used in the last investment casting procedure to achieve the desired results.
Benefits of Investment Casting: Is It Worth It?
Investment casting is a process capable of making high accuracy and intricately detailed casting objects better than other similar manufacturing processes. These are not the only benefits.
Here is a list of a few of the benefits of investment casting:
- Sustainability: The wax and the metal alloy from the process are always reused as the objects are made to a precise shape; therefore, there is no overall wastage.
- Wide Range Application: As mentioned earlier, investment casting is used in many different industries. The primary reason behind this is the metal alloys used in the process.
- Exceptional Surface Finish: Investment casting has some actual smooth finishing, and this will reduce the amount of secondary machinery required, along with time and energy, compared with the other manufacturing process.
- Flexible Design: Investment casting is ideal for making complex parts, including complex shapes, thin walls, and intricate designs, mainly due to its adaptability.
Investment casting doesn’t have any limits as the process can create any object with any size, thickness, and shape. Additionally, the production methods make it highly flexible.
So with all these reasons mentioned above, the hype and popularity investment casting has gained throughout the years is worth it.
Conclusion
Investment casting is undoubtedly the ideal manufacturing process suitable for making all sorts of objects with detailed designs and is used in many industries. And by going through these all points and descriptions, you will now be able to understand what exactly it is.