Ultrastable ceramic nanocomposites for telescope mirrors

MATERIALS WITH NULL OR TAILORED THERMAL EXPANSION IN A WIDE RANGE OF TEMPERATURES

The CINN has developed a new family of alumina-zirconia nanocomposite materials that feature excellent mechanical properties (outstanding values of bending strength, toughness, hardness…) and a complete palette of grey colours. The final colour of the ceramic material is obtained by means of adding diamond nanoparticles and can be tailored in a simple and precise way just adjusting the content of diamond nanoparticles and the sintering temperature.

INNOVATIVE ASPECTS

CSIC developed a new and simple preparation process of lithium aluminosilicates with negative thermal expansion coefficients that requires inexpensive precursors (kaolin powders, lithium carbonate, etc.) and employs conventional and well known, within the ceramic industry, thermal and mechanical treatments. The result of this preparation procedure is an economic material with excellent thermal properties that combined with positive thermal expansion second phases allows the manufacture of composites with tailored, including null, CTE. Using this approach ceramic nanocomposite materials with non-oxidic second phases and showing a CTE lower than 1x10-6 K-1 in the temperature range (-150 ºC +150 ºC) can be obtained by a simple process that comprises conventional sintering methods, thus opening the possibility of manufacturing components with complex shapes and large dimensions. The patent portfolio also includes materials with only oxidic components and tailored thermal expansion coefficient, including materials with zero thermal expansion. These materials can be used in oxidizing atmospheres at elevated temperatures while maintaining excellent mechanical properties.

Proof-of-concept 200mmØ Blanks

MAIN ADVANTAGES

The main asset of this new class of ultrastable materials is the use of simple and inexpensive procedures of synthesis and processing of lithium aluminosilicate powder. The resulting nanocomposites have no glassy phase, therefore feature excellent mechanical properties compared to commercial glass-ceramics and have a controlled CTE in a wider temperature range than any other known material. Additionally, the optional use of carbon nanofibers gives the composites, excellent electrical properties, which allow their machining by means of Electro Discharge Machining (EDM) techniques.

APPLICATIONS

  • Extreme Ultraviolet Lithography: masks, mirrors and wafer stages
  • Space and Earth Observation Systems: mirrors and structures Gyroscopes and Mirrors & structures for countermeasure systems
  • Metrology: Reference standards
COLLABORATION OPPORTUNITIES

Industrial partner to establish a joint venture

Other potential interests are:

Licensing of patent portfolio and Know-how

Technical cooperation, subcontracting and R+D consultancy.

Development of joint R+D Projects

CONTACT DETAILS

Adrián Alonso

Responsable de Innovación

Email:

Tel. +34 985733 644 Ext. 213