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Plochingen, 2010-09-16

One type of ceramic – numerous applications

CeramTec: Zirconium oxide is first choice for mechanical engineering

Zirconium oxide helps securely seal crown caps and prevents brake fluid in vehicle braking systems from overheating. It is not affected by highly abrasive yarns, is used to manufacture wires and also plays a role in making dental prostheses. It is hard to imagine a more versatile set of application areas for zirconium oxide. The experts at CeramTec GmbH in Plochingen offer support in solving problems related to wear, corrosion or thermal insulation, namely with advanced ceramics whose potential is far from exhausted.

At first glance it seems unusual that ceramics of all materials would have the same linear expansion coefficient as steel. However, a closer look at this reveals a number of astounding possibilities. This is what makes it simple to create composite steel and ceramic components that ideally combine the best properties each material has to offer. The Young's modulus of both materials is also the same. For years, this has been a proven combination of materials, for instance in wire drawing or seal rings for crown caps in bottling plants. This increases component life thanks to the low friction levels and, consequently, reduced wear. Similarly, it prevents cold welds and helps protect lettering and colors on crown caps.

This is where the similarities between ceramic and steel end. After all, both its friction coefficient and specific weight make ceramic the clear winner in the battle for the best material. While superior glide properties ensure less friction and contamination of the material being processed, advanced ceramics are also up to 25 percent lighter than steel, despite their remarkable density. Moreover, zirconium oxide is both electrically and thermally insulating. The latter helps promote desired warm-cold separation. A positive example of the use of advanced ceramics as an insulation component can be found in the automotive industry. Installed in brake calipers, advanced ceramics prevent heat generated during braking from transferring to the brake fluid. Using advanced ceramics in forming processes prevents cold welds from developing.

The smaller the grain size of the ceramic material selected, the greater the cutting edge stability provided. Yet another impressive feature of zirconium oxide is that it is highly ductile and has a flexural strength of up to 1,400 N/mm2. These properties are leveraged during technical cutting, for instance in the textiles industry. Superior cutting edge stability is also of particular interest in medical products applications, e.g. for dental prostheses such as crowns, bridges or implants. Ceramics are also bioinert, meaning that they can be used to make dental prostheses without causing undesirable interactions with the body. Likewise, chemical substances such as acids and lyes don't stand a chance – they have no impact on ceramic materials. Thanks to its non-metallic origins, zirconium oxide is also not susceptible to corrosion.

Wherever zirconium oxide is used, it delivers convincing performance due to its high quality and low rate of failure. This translates into less machine downtime and greater productivity. Zirconium oxide ceramics from CeramTec GmbH are available in yellow or white depending on customer requirements and necessary adaptations for the specific field of application. This is relevant in cases where advanced ceramics are an integral part of mill technology, for example. Manufacturing grinding balls and rotors from a uniform, white material prevents color contamination in white dispersions.

In general: Zirconium oxide is the ideal material for developing new fields of application or replacing steel components in machine and equipment construction applications that demand wear resistance, corrosion resistance or electrical and thermal insulation.