You might have heard that aluminum oxide ceramics are the most popular industry-grade material used in ceramic injection molding (CIM). And if you’re not so much into the technical stuff, you might have postponed your research about this popular material.
But now that your time has come, we can only make the adventure non-jargony and comprehensive.
Let’s unravel aluminum oxide ceramics in CIM.
What is Alumina Ceramic?
Alumina, or aluminum oxide ceramics, are long-wearing, characteristically hard, corrosion-resistant materials that operate optimally in extreme temperatures. They demonstrate incredible properties that are relatively outstanding and in high demand in modern manufacturing systems.
Alumina ceramic is a technical ceramic, considering its incredible price and properties to performance ratio. It exhibits different grades, depending on alumina concentration, which ranges from 70 to 99.9%. The higher the alumina concentration, the stronger, more resilient, and higher the output performance.
Alumina ceramic undergoes severe conditions in ceramic injection molding to give highly intricate designs and shapes.
Let’s give it a closer look!
Al2O3 Compound
Alumina ceramic is produced from aluminum oxide (Al2O3) and used in various high-performance industry applications. It is a highly resistant material that can withstand temperatures as high as 2,000°C.
Hence, it exhibits resistance to chemical corrosion, erosion, and wear.
The material can be handled at cryogenic conditions too, without losing its mechanical and chemical properties.
For instance, Al2O3 ceramic is very popular in biomedicine for its bioinert properties. Meaning, it hardly reacts with human tissues, which would normally cause allergic reactions. Thus, it is heavily used in dentistry, orthopedics, and other treatments that involve contact with human tissues.
What about high-performance industrial applications?
Al2O3 compound operates optimally in industry processes that entail very high or low temperatures with abrasive action. It is mostly preferred for its ability to adapt to different high-end industry needs and perform just well.
For instance, a company in need of chemically inert combined with average heat transfer properties is better with alumina than zirconia. The latter enhances heat transfer to extreme levels.
With alumina ceramics, also, you can solve many general problems involving gas permeability, mechanical integrity, high density, and price-to-performance ratio.
Alumina Chemical Structure
Al2O3 compound is extracted from naturally occurring bauxite and corundum. Alumina is an indispensable raw material in industries like biomedicine, electrical insulation, electronics, and grinding media.
Alumina’s complicated extraction process is a telltale sign of a high-performance compound. It is primarily formed by combining oxygen and aluminum molecules.
The molecules form different chemical structures, with gamma and alpha-alumina being the most prominent. Alpha, however, is the only thermodynamically stable phase, characterized by a hexagonal close-packed structure.
1. Alpha-type Alumina
Alpha-type exhibits a very large lattice energy owing to its closely packed oxygen ions, which surround symmetrically distributed Al3+.
A high melting point and boiling point characterize it. In its high-purity form, it is used to synthesize artificial ruby, sapphire, and corundum.
2. Gamma-type Alumina
The gamma-type ion structure forms octahedral and tetrahedral gaps. Produced at between 140 and 150℃, oxygen ions attach to irregularly distributed Al3+.
This phase is insoluble in water but may react to strong acidic and alkaline conditions. Hence, it is characteristically porous with high activity and a strong adsorption capacity.
Alumina Ceramic Properties
To produce alumina ceramics, manufacturers use a white, silky, and dense powder that material resembles table salt. However, the powder is a bit granular and very fine. Aluminum oxide is grouped into three, depending on soda, iron, and silica concentration.
Calcined alumina is 99% pure and a 9 hardness level on the Mohs scale. Whereas tabular alumina forms by heating calcined alumina to 1600°C. It exhibits high heat capacity and refractory features.
Alumina hydroxide is mostly used in glaze slurries and as an adhesive.
Physical Properties of Alumina Ceramic Material
Alumina ceramic’s high temperature resilience is a tell tale sign of its incredible strength in high temperatures. Most metals will lose structural integrity when temperatures lower to normal. However, alumina ceramics are rigid to temperature fluctuations.
Alumina demonstrates impressive thermal and dielectric properties. The material exhibits high thermal resistivity and inhibits thermal shock. It is a perfect insulating material, as it hinders the flow of electric current.
|
Property |
Value |
|
Melting point |
2072°C |
|
Boiling point |
2977°C |
|
Thermal conductivity |
30W/m·K |
|
Electrical resistivity |
10^14 ohm·cm |
Mechanical Aluminum Oxide Ceramic Properties
Alumina ceramic demonstrates very high hardness, density, and tensile and compressive strength. The advanced material ranks as second to diamond according to Rockwell hardness and on the Mohs scale.
Hence, it is used for bearings and mill linings, showing strength that’s way exceeds tungsten and stainless steel carbide components.
A test on alumina ceramic’s mechanical strength shows a material with great endurance and superior hardness. This characteristic improves with higher alumina concentrations.
Speaking of its density, alumina ceramics are characteristically dense. This is depicted by the material’s fine particles that form patterns with no voids, hence high density.
|
Property |
Value |
|
Density |
3.99g/cm³ |
|
Hardness |
9 Mohs |
|
Compressive strength |
4000 MPa |
|
Tensile strength |
300 MPa |
|
Young’s modulus |
380 GPa |
Alumina Ceramic Material Chemical Properties
Alumina is:
-
Chemically stable at extreme temperatures
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Reactive to both strong acids and alkalis, and strong reducing agents
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Highly resistant to corrosive agents
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Highly refractory with high thermal resistance
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Resistant to chemical attacks
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Reacts with chemicals such as hydrofluoric acid and phosphoric acid
Different Grades of Alumina Ceramic Material and Their Applications
Alumina ceramics are classified according to the amount of aluminum oxide they contain. A ceramic material is considered pure alumina when there are few or no other elements added into the mixture.
Depending on the amount of other elements, a ceramic material can have 70-99%+ alumina concentration.
|
Alumina Grade |
Characteristics |
Industry Use |
|
92% alumina |
High mechanical strength, wear resistance, high density and corrosion resistance |
Grinding media, electrical packaging, wear resistant tools, and bushings |
|
94% alumina |
High volume resistivity, low thermal expansion, abrasion resistance, and dielectric constant. |
Electron tube, electric insulation, bearing coatings, and laser products. |
|
95% alumina |
High hermeticity and flexural, and compressive strength. |
Medical implants, X ray components, military body armor components, and high voltage bushings. |
|
97% alumina |
Excellent thermal and electrical properties |
Electrical insulator, X ray equipment, vacuum systems, electron microscopes, microwaves, and medical equipment insulation. |
|
97.6% alumina |
Enhances operational reliability and stability. Enhances electrical stability in fluctuating temperatures. |
Laser parts, sensors, X ray components, and flow measurement. |
|
99% alumina |
Extremely hard and has excellent chemical resistance. |
Leveraged in the chemical industry in production of thrust washers, plungers, shafts, and counter face seals in chemical pumps. |
|
99.9% alumina |
Ultra pure alumina |
Plasma etching tools and nuclear insulation components |
Ceramic Injection Molding
Ceramic injection molding involves intimately mixing ceramic powders with organics using special mixing equipment. The operator granulates the mix into uniform pellets before liquefaction, where they are molded. Debinding follows where the mold is placed in a kiln (set to very high temperatures) to eliminate the binder.
The operator subjects the component to extreme kiln temperatures, where sintering occurs. Simply, the component densifies as its volume reduces. The process gives slick ceramic products that other manufacturing processes might take time and a higher budget to produce.
CIM is a reliable manufacturing method where quality repeatability and highly intricate products are needed.
Binders are either polymers or waxes that help to make the ceramic powders moldable. The manufacturer can create complex designs and shapes only when the ceramic powders are transformed into moldable feedstocks.
Some ceramic powders cannot undergo high-temperature conditions without losing their physical and chemical properties. However, Al2O3 ceramics help solve that by their optimal performance under extreme temperatures.
Benefits of Alumina Ceramics in Ceramic Injection Molding
1. Less Carbon Footprint
Alumina ceramics’ resistance to high temperatures enhance energy production. The material won’t incinerate in high temperatures, which would otherwise produce more carbon dioxide.
Besides, CIM involves very intense but fewer processing steps than other technologies.
Hence, when alumina ceramics are manufactured using this technology, they are ready for sale, rather than needing machining or more processing.
2. Good Return on Investment
Aluminum oxide and other elements used in the manufacture of alumina ceramics are readily available. Ease of access to these raw materials gives them a relatively friendly pricepoint, cutting down on shipping costs and transit time.
Alumina ceramics are molded into intricate, sophisticated designs that sell out for their aesthetic appeal. Hence, you can get any complex and unique shapes and grow your niche amid the current global aesthetic craze.
3. High Durability Applications
One of the most impressive qualities of alumina ceramics is their wide use in high durability industry uses. The materials’ structural, mechanical, and thermal properties allow their usage in a variety of industries that need a high performance output.
This means, they need a material that would be relatively lightweight and last for considerably long before replacement. Alumina ceramics come with all these qualities.
4. Variety of Industry Applications
Alumina ceramics are heavily used in the following industries:
-
Aerospace
-
Orthopedics and dental prosthetics
-
Machining abrasives and cutting tool inserts
-
Electronics and electrical devices as insulating components
-
Corrosion- and wear-resistant components in valves and pumps
-
Ceramic bearings and seals
Market Research and Futurism of Al2O3 Ceramics in CIM
Recent research has tried to make Al2O3 ceramics eco-friendly materials. Researchers are trying to combine Al2O3-based fillers with PEG and CAB to minimize the carbon footprint associated with CIM.
The nanotechnology revival is also sweeping across CIM systems. Researchers are looking for ways to improve the mechanical strength and thermal resistance of ceramic components. One way they have found is using nano-sized aluminum oxide particles.
Thus, Al2O3 ceramics’ relevance can expand more in the aerospace and auto industries.
According to Market Research, the Al2O3 market could spiral to 35.4 billion US dollars by 2030. There’s no better time to hop into such a futuristic material!
Take Bold Steps into The Future With Us!
GORGEOUS is a successful advanced ceramic supplier with a futuristic outlook. We incorporate both trendy and traditional ceramic manufacturing systems for both conventional and customized needs. With excellent customer service, we ensure your ceramic needs are met, positioning you in a more successful trajectory.
Talk to us today and slot your Al2O3 market both now and for the future.