Do you want to know what ceramic injection molding and related processes are? Whether you’re a manufacturer or simply interested in learning about ceramic injection molding, this blog post is for you. This article covers everything about ceramic injection molding: basic concept, technique, processes involved, applications, advantages, and disadvantages. Keep reading.
What’s ceramic injection molding, and what’re its advantages?
Ceramic injection molding (CIM) or powder injection molding is an advanced manufacturing process for creating complex, three-dimensional ceramic parts.We use CNC machining to make formed ceramic molds to achieve the highest forming mold accuracy. For CIM, the fine raw ceramic powder material is mixed with the binder to create a homogenous feedstock. (A critical factor in CIM is the particle size distribution or PSD of the raw ceramic powder. PSD influences the flowability and packing density of the feedstock).
Then, prepared feedstock is heated to soften the binder and let the mixture flow easily through the machine. The machine moves this soft mixture into the mold to create the product known as “green product.” After cooling the molded product, the binders are removed using heat or chemicals. Furthermore, sintering strengthens the finished product, giving it the desired durability.
First introduced in 1920, ceramic injection molding was initially used to produce spark plugs. Later on, in 1970, the advanced process was developed following the footprints of metal injection molding. Today, CIM is widely used to produce an extensive range of parts for electronics, automobiles, aerospace, construction, and medical.
Types of ceramic materials used in CIM
All raw ceramic materials are refractory materials with excellent heat resistance, thermal conductivity, corrosion resistance, and electric insulation.
Depending on the finish product’s required characteristics, like strength, porosity, insulation resistance, and durability, you need to use different ceramic materials. Here is a list of the most common raw ceramic materials that you can choose:
Alumina (Al₂O₃)
Aluminum oxide or alumina is a refectory material that can be obtained in raw crystalline powder form.
Zirconia (ZrO₂)
Coming from Zirconium, Zirconia is a hard powder-like ceramic material. You can use it to manufacture cutting tools and dental implants.
Silicon Nitride (Si₃N₄)
Silicon nitride is a relatively high-grade ceramic material. Because of its exceptional heat resistance, thermal conductivity, and isolation, it’s suitable for challenging uses like automotive and aerospace.
Silicon Carbide (SiC)
Even better than silicon nitride, silicon carbide is the highest-grade synthetic ceramic material. It’s a combination of silicon and carbon. Considering its matchless heat resistance, you can use it to make high-end ceramic products.
Advantages of ceramic injection molding
Suitable for high-end, precise product manufacturing
Ceramic injection molding is incredibly suitable for manufacturing high-performance products. These products must stand the test of heat, electric current, weather, and thermal shock.
Not only this, but these products must also have excellent finishing to align with their further usage requirements.
Cost efficiency for intricate designs
In the first place, ceramic manufacturing using injection molding seems pricey. However, manufacturing 3D ceramic products using some other methods can take significant time and also cause material waste.
Such drawbacks translate to overall added cost. This is why you can collectively reduce your manufacturing costs by opting for quick and materially efficient manufacturing processes. But, remember, while creating injection molded products in small quantities, the costs can be significantly high.
Controlled quality
Ceramic products used under challenging conditions, like automotive, aerospace, and electronics, need precession from design to their attributes. They must have 100% accuracy. Otherwise, the resulting loss can be beyond estimation. In such a case, using more systematic methods like CIM can get thousands of similar parts of the same standards.
What’re the applications of ceramic injection molding?
Because of their incredible preciseness, aforementioned qualities, and low chemical reactivity, injection-molded ceramics products have a wide range of applications. Some of these are as follows:
Medical tools and equipment
The medical industry sometimes needs very precisely made, strong tools and equipment that are not chemically reactive. For example, dental implants need to fight a food’s acidic and abrasive nature. In such cases, injection molding helps you create ceramic products that are the fittest option.
Electronics
Parts and tools used in electronics must be strong and current-resistant but have intricate and uniform designs for extensive use. That’s where ceramic injection molding helps you by manufacturing products like insulators, substrates, and connectors.
Industrial Machinery
Industrial machinery parts like seals, cutting tools, and ball bearings have to face brutal use. Therefore, these products have to be extraordinarily durable and resistant to chemical reactions.
And, of course, you can’t overlook the precision of the design that you need. Thankfully, ceramic injection molding helps you make such products using ceramic materials.
Aerospace and automotive
In aerospace and automotive industries, engine parts, nozzles, and sensors should be wear and electric-current-resistant. CIM allows you to make these compatible parts.
These were only a few applications of ceramic injection molding manufacturing. However, the utilization exceeds to create parts of luxury goods like mobile phones, watches and jewelry. In the same way, it assists you in making equipment and parts for energy sectors.
Step-by-step process overview of ceramic injection molding
The ceramic injection molding process involves several key steps that you need to follow carefully. Here is an overview of this step-by-step process.
1. Selecting the injection molding machine meant for ceramics
The CIM process starts with the careful selection of injection molding machines. These machines are more specialized than plastic injection molding machines as they can handle more heat and abrasive use necessary for the molding of tough material like ceramic.
2. Collecting and mixing the raw material
After you have the compatible equipment, you need raw ceramic materials like zirconia, alumina, silicon carbide, or silicon nitride. Here, it’s crucial to consider the particle size distribution of ceramic powders as it affects the flowability and packing density of the feedstock. Then, you need binders acting like water to solid powder at the injection stage. You can choose ceramic and binder materials following your engineers and experts’ recommendations.
3. Converting the material into pellets for even feeding
At this stage, thoroughly mix the binders with the raw ceramic material to create a homogenous mixture. This material can be hard, like big pebbles.
So, you may need to grind it to transform it into powder and then into pellet form. The pellet form will aid in an even feeding.
4. Feeding the machine with the ceramic material
At this simplest stage, feed the machine with the prepared stock.
5. Softening of the material
The machine will push these pellets into the hopper, where intense heat will change the state of the mixed material into flowable form. It happens because of the melting of binders.
6. Injection molding phase
At the end, the machine will inject the melted material into molds. The product you achieve at this stage is called “green body.”
This product is in its infant phase — pretty fragile. So, handle it carefully.
7. Removal of binders
Finally, you need to remove binders from this ceramic product through heat, catalyst or solvents. Exact debinding depends on the type of binders used.
8. Sintering for extra strength
Now, the products need heating once more, but below their melting points for extra strength.
9. Finishing and packaging
Although the injection molded ceramic product has covered its manufacturing journey, you might need to add extra finishing before packaging.
Conclusion
Ceramic injection molding is an excellent method for creating high-quality ceramic products. All you need is the right equipment, materials, and experts to handle the manufacturing process. However, if housing the entire setup costs you more, you can also get injection molded products from the original manufacturers.