GREY ALUMINA-ZIRCONIA NANOCOMPOSITES FOR JEWELRY
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.
The excellent mechanical properties as well as the good chemical stability and biocompatibility featured by zirconia materials have promoted its use in many applications. However in sectors where aesthetics are a key aspect such as jewelry or decoration the use of zirconia materials has been traditionally restricted due to the narrow range of colours attainable, which varies from white to ivory depending on the kind of atmosphere in which the sintering is performed and the type of oxidic stabilizer used. To provide a greater variety of colours in zirconia materials different approaches have been used such as the immersion of pre-sintered zirconia blanks in solutions with ionic salts or the use of different oxides as doping agents. However, these methods can lead to the generation of defects and the subsequent loss of mechanical properties in the final material. The novel alumina-zirconia materials overcome the before mentioned problems and combine colours within the CIE L*a*b* colour system corresponding to values of the index L* between 40 and 98 and excellent mechanical properties such as flexural strength greater than 1500MPa and toughness values higher than 14MPam1/2.
The main advantages of these nanocomposites over conventional Alumina-Zirconia nanocomposites are:
- Wide range of metallized grey colours
- Homogeneous coloration
- Excellent mechanical properties
- Medical devices
- Cutting tools
Licensing of patent and Know-how
Technical cooperation, subcontracting and R+D consultancy.
Development of joint R+D Projects for the adaptation of the SPS technology to the industrial needs.