With technological advancements, ceramics are no longer limited to everyday life. They occupy an increasingly important position in many fields such as semiconductors, mechanical engineering, consumer electronics, biomedicine, textiles, and automobiles. Moreover, they have acquired a new name: advanced ceramics. This article will introduce you to advanced ceramics and how it differs from traditional ceramics.
What is Advanced Ceramics?
The history of traditional ceramics can be traced back to the Neolithic Age thousands of years ago. Traditional ceramics are made from natural minerals, using traditional ceramic forming and firing processes. Its main applications are daily-use ceramics, building and sanitary ceramics, and ceramic artworks.
Advanced ceramics is a new type of ceramic material developed in the mid-20th century. It is also known as “technical ceramics”, “fine ceramics”, or “industrial ceramics”. Advanced ceramics are made from artificially synthesized ceramic powders through a series of complex and highly precise manufacturing processes. They possess unique properties that traditional ceramics cannot match.
Key Differences Between Traditional Ceramics and Advanced Ceramics
The key differences between traditional ceramics and advanced ceramics lie in their raw materials, manufacturing processes, properties, and application fields.
Raw Materials
Traditional ceramics primarily use natural minerals as raw materials, such as clay, quartz, and feldspar. Advanced ceramics, on the other hand, use artificially synthesized ultra-fine powders, such as oxide ceramics (Al2O3, ZrO2, etc.) and non-oxide ceramics (such as SiC, Si3N4, AlN, etc.). Their composition is controllable, allowing for precise customization of material properties (such as enhanced toughness and improved thermal conductivity).
Manufacturing Processes
Traditional ceramics are typically formed using processes such as grouting, slurry molding or clay shaping, and generally require no further processing after high-temperature firing. However, the manufacturing process of advanced ceramics is more complex. Commonly used forming processes include dry pressing, hot pressing, isostatic pressing, tape casting, extrusion and injection molding, and may require additional post-sintering processing to achieve ultra-high precision and performance optimization.
Properties and Applications
Through the comparison in the table below, we can clearly see the differences between advanced ceramics and traditional ceramics in terms of properties and applications.
| Property | Traditional Ceramics | Advanced Ceramics |
| Raw Material | Clay, quartz, and feldspar | Synthetic powder (e.g., Al2O3, ZrO2, etc.) |
| Purity | Containing a high amount of impurities | High purity |
| Manufacturing Process | Simple forming; firing at 800-1200℃ | Precision forming; sintering at 1400-2000℃ |
| Precision Machining | Not involved | Can be done if needed |
| Microstructure | Coarse grains and many pores | Small grains and dense structure |
| Mechanical Strength | Low, brittle | Very high, some comparable to metal |
| High Temperature Resistance | Limited | Excellent |
| Application | Daily-use ceramics such as tableware and tea sets, building and sanitary ceramics such as tiles and bathroom fixtures, and ceramic artworks. | For use in extreme environments, high-precision applications, or specialized functions (such as semiconductors and medical implants). |
Conclusion
Advanced ceramics and traditional ceramics differ in raw materials, manufacturing processes, properties, and applications. These differences give each a unique value in its respective field.
FAQs
Q1: How are ceramics classified by use?
A: Ceramics can be divided into four categories based on their use:
- Daily-use Ceramics: Ceramic products used in daily life for dining, cooking, decoration, and other purposes, such as plates, bowls, cups, saucers, and other tableware. They are indispensable household ceramics.
- Building and Sanitary Ceramics: Ceramic products used for building decoration and sanitary facilities, such as wall and floor tiles, facing tiles, washbasins, bathtubs, etc.
- Ceramic Artworks: Artistic pieces possessing unique artistic and aesthetic value, such as ceramic sculptures, murals, and decorative items.
- Advanced Ceramics: Ceramic materials produced using high-purity inorganic raw materials through precise chemical metrology and modern preparation techniques. They differ fundamentally from traditional ceramics in raw material selection and process control. They emphasize composition purity and microstructural design to achieve outstanding comprehensive properties.
Q2: Do advanced ceramics exhibit “creep” behavior like metals at high temperatures?
A: Yes, but to different degrees and through different mechanisms. Advanced ceramics also creep at very high temperatures near their melting point, but their creep resistance is generally far superior to that of superalloys. This is one of their key advantages in the hot section of aircraft engines.
Q3: Can ceramic components be reliably bonded to metal? What solutions are available?
A: Yes. Common and reliable connection methods include:
1. Brazing: Using an active brazing filler metal to form a strong metallurgical bond with the ceramic surface.
2. Adhesive Bonding: Using high-performance epoxy or silicone adhesive, suitable for non-high-temperature applications.
3. Mechanical Fastening: Using clamping, cladding, and other designs to avoid direct threading on the ceramic.
Q4: In terms of corrosion resistance, are advanced ceramics superior to special alloys such as Hastelloy?
A: In most corrosive environments of strong acids, strong alkalis and molten metals, the corrosion resistance of advanced ceramics (especially alumina, zirconia and silicon nitride) far exceeds that of the best specialty alloys, with no risk of intergranular corrosion and a longer service life.
Q5: In the field of dentistry, why is zirconia (ZrO2) the preferred ceramic material for dental implants?
A: Because zirconia has high toughness, high strength, excellent biocompatibility (no rejection reaction) and low thermal conductivity. In addition, its milky white appearance is very close to natural teeth, and the aesthetic effect is excellent.
Q6: What are ceramic matrix composites (CMCs)? Are they more advanced than advanced ceramics?
A: CMCs are composite materials that incorporate fibers (such as carbon fibers and SiC fibers) within a ceramic matrix. While not necessarily “more advanced,” they address the core pain point of monolithic ceramics: brittleness. CMCs possess metal-like toughness and are immune to catastrophic fracture, making them a core material for the next generation of aircraft engines and brake systems.
Q7: Are advanced ceramics environmentally friendly?
A: Yes, advanced ceramics are environmentally friendly throughout their lifecycle. They are non-toxic, chemically inert, and do not pollute the environment. Their excellent wear resistance and long lifespan reduce resource consumption. In the energy sector (fuel cells, lithium batteries), they are key materials for achieving green energy.
Q8: Can 3D printing technology be used to manufacture advanced ceramic parts?
A: Yes, and it’s currently a hot research topic. Ceramic 3D printing (such as stereolithography (SLA) and binder jetting) can produce complex geometries that are impossible with traditional manufacturing processes, making it ideal for prototyping and low-volume customization. However, its strength and density are generally lower than those of parts produced through traditional forming and sintering.
