Technical ceramics | Extremely hard and temperature-resistant

Technical ceramics is characterized by its exceptional hardness, temperature resistance and chemical stability, making it ideal for demanding industrial applications. These materials offer excellent Wear and corrosion resistance and are used in areas such as automotive engineering, medical technology and electronics. The article presents innovations and applications of technical ceramics in industry.

Content

• Silicon nitride ceramics grades for turning cast iron
• Patented technical ceramics exceed the hardness of steel
• Micro injection molding made of technical ceramics for endoscope tip
• Glass-ceramic as a construction material of high quality

Silicon nitride ceramics grades for turning cast iron

24.03.2022 | Ceramtec is expanding its range of high-tech cutting materials to include silicon nitride ceramic LKT 100 for highly efficient turning of cast iron. The new cutting material combines the toughness typical of silicon nitride ceramics with increased wear resistance. This was made possible by a manufacturing process that allowed the developers to influence the composition of the cutting material in the outer functional zone.21.03.2022 | 

“The new cutting material LKT100 offers very good toughness with excellent wear resistance and, in particular, high notch wear resistance,” explains John Schneider, Senior Product Manager Cutting Tools at Ceramtec. "It allows large material removal rates and thus enables advantageous cost-per-part machining results. We have developed the new cutting material for turning and boring GJL materials in smooth to heavily interrupted cuts.

Typical workpieces are, for example, brake discs, brake drums and other mass-produced components made of cast iron orEngineshousings made of GJL that have to be drilled out. the material LKT100 is suitable for roughing and roughing-finishing with non-uniform and fluctuating allowances and also creates high chip cross-sections.”

Ceramic cutting materials and cutting speeds up to 1000 m/min 

The indexable inserts made of the new ceramic cutting material have particularly striking properties on the outside. Fine color nuances of the ceramic surface indicate the newly developed processing step for increased wear resistance. The toughness behavior is retained. This allows a wide range of uses from smooth, continuous cuts to interrupted cuts and large chip cross-sections. The shades of color do not reduce the cutting performance.

The LKT 100 ceramic cutting material is for Cutting speeds from 400 to 1000 m/min designed. The cutting depth is up to 4 mm with feeds of 0,15 to 0,5 mm. The optimal data depends on the intended use.

Patented technical ceramics exceed the hardness of steel

11.01.2021/XNUMX/XNUMX | The new Technical ceramics Metal-like Ceramic by Global Precursor Ceramics (GPC) combines for the first time the advantageous material properties of Ceramics and Steel. The start-up company's patented high-performance ceramics offer new perspectives for many areas of application from Rolling elements to Linear System.

“The steel-like ceramic material is an absolute novelty on the market. This opens up completely new possibilities in industrial production, ”says Prof. Dr.-Ing. Stephen Sommer from the University of Applied Sciences Würzburg-Schweinfurt, Faculty of Mechanical Engineering.

The material Metal-like ceramic (MLC) combines the low weight and high hardness of ceramic with the mechanical parameters such as the modulus of elasticity and thermal expansion coefficient of steel. The manufacturing process also enables a significantly higher geometry variance and reduces the effort for subsequent machining.

Technical ceramics lighter than steel

Compared to steel, the technical ceramic MLC saves up to 50% in weight. Nevertheless, the material has a Hardness of 1000 HV on. The ceramic material is very malleable, temperature resistant up to 800 ° C, has a high load-bearing capacity and can slide without lubricants. Metal-like ceramic is produced pore-free and shaped to near net shape. Small series production is possible using these technical ceramics.

Near net shape shaping 

First of all, the high-performance ceramics become one polymer base material made, which is enriched with active and passive fillers. This allows precise and near-net-shape shaping in, for example, extrusion processes or injection molding processes.

Then the material is at over 800 ° C temperatures ceramized or pyrolyzed. Chemical reactions with the fillers transform the polymer matrix into a ceramic product. A slight decrease in volume of 5 to 8% is already factored in. If the ceramic materials are intended for high-precision components, they can be reworked quickly. This guarantees mechanical properties such as a moderate hardness of 1000 HV.

Different applications for the MLC ceramics

Users in a wide variety of industrial sectors benefit from the advantageous properties of the new ceramic material. MLC is suitable for components in Clean room and vacuum or in corrosive or polluted environments. Even poor lubrication conditions do not affect the performance of technical ceramics.

Matching other applications technical ceramics are also those PCB and semiconductor manufacturing, Electronics, Mechatronics as well Measuring and testing technology, In addition come the Food industry, Textile industry, Welding technology, Lightweight construction as well Medical Technology, Extruders and injection molding machines.

Micro injection molding made of technical ceramics for endoscope tip

21.04.2020 | Sembach Technical Ceramics has recently started manufacturing small parts in Micro injection molding Process. Micro injection molding is not yet very common in the ceramics industry. Manufacturers of medical technology often lack knowledge of the materials used in technical ceramics. However, these offer a number of positive properties. This makes them particularly suitable for miniature components in medical technology.

Micro injection molding is used for components weighing between 0,01 and 0,5 g. Some parts are so small that they only with the help of a magnifying glass are recognizable. Micro injection molding differs from classic injection molding in that it has a very small injection unit. This is integrated in the injection molding machine instead of the normal sized unit.

This micro injection molding Injection unit is based on a different technology than normal injection molding technology. A piston press is used instead of the usual screw shaft. The piston is so small that it can carry very small amounts of material. It is important to monitor the process. With the small injection unit, the minimal piston movements can be scaled and the smallest quantities can be measured and monitored.

Technical ceramics for medical devices

Parts for Medical devices are predestined for the micro injection molding process. The manufacture of medical components is subject to sensitive requirements, especially when it comes to components that are in direct contact with Body tissue stand. The material is suitable for this Ceramics, usually oxide and non-oxide ceramics, because they are particularly biocompatible, corrosion-resistant and wear-resistant. Typical small parts made from micro injection molding are, for example, miniature feedthroughs for tips for endoscopes for minimally invasive procedures, cardiac pacemakers or tools for miniature components.

1 mm² image sensor enables the world's smallest digicam

IATF 16949 certification

Sembach fulfills the strict regulations of the micro injection molding process Certification according to IATF 16949. For example, the company manufactures miniature bushings for pacemakers. The volume of this part is 13,9 mm3. It weighs only 0,055 g. Quality control following the manufacturing process of the micro parts can be carried out at Sembach, depending on the number of items, by visual microscope inspection or automatically as an optical 100 percent inspection with camera systems.

Glass-ceramic as a construction material of high quality

04.09.2013 | The mica glass ceramic “Vitronit” from Rheinbach Materials Center (WZR) is becoming increasingly popular among designers and development engineers. This pore-free ceramic material is a popular alternative, particularly when plastics or metals reach their limits. It is temperature-resistant up to 1000 °C and can be machined using conventional tools. High-quality prototypes and series parts with sometimes astonishing properties are now being manufactured from it.

The Ceramic Vitronit is a modern construction material of high quality. If, for example, high-temperature-resistant components are required that also have to be electrically insulated, Vitronit is more suitable than metals or plastics. In addition, since the thermal expansion of this glass ceramic is very similar to that of steel, composite solutions can also be implemented. Another key advantage of Vitronit is its good mechanical machinability with conventional precision tools.

Many designers and product developers not only produce prototypes, but increasingly also ready-to-install series parts Vitronic Surface qualities of Ra <0,2 µm can be achieved.

After shaping, no further firing process is required. Ready-to-install customer parts include electrical and thermal insulation Mouldings, which must prove themselves in use through high resistance to frequent temperature changes, corrosion and chemicals. Flanges, charging elements, wearing parts as well as connecting and drive elements (screws, threaded rods) are also made from this glass ceramic. The design potential of Vitronit is far from being exhausted.

The material is white as standard, non-porous and non-outgassing. The density of the material is 2,66 g / cm³ and its thermal expansion coefficient between 9,5 x 10^-6K^-1 and 11,3 x 10^-6K^-1, The thermal conductivity is 1,72 W / mK (at 25 ° C). Particularly noteworthy are the electrical breakdown strength of 12 kV / mm, the flexural strength of 120 MPa and the compressive strength of 450 MPa. With its strength values, vitronite is slightly lower than the ceramic materials aluminum oxide and zirconium oxide.

Source: This article is based on information from the following companies: Ceramic, Ceramtec, Sembach, WZR.