Regardless of whether it´s to be used as a filigree lightweight mirror substrate for satellites and space telescopes or as a component in lithography, the glass-ceramic ZERODUR® that exhibits extremely low thermal expansion is ideally suited for sophisticated applications in which changes in temperature and static and dynamic stresses place high demands on construction materials. SCHOTT researcher and optics expert Dr. Peter Hartmann has developed a model that allows for the very accurate prediction of the strength and service life of ZERODUR® components that are used in high stress environments, such as astronomy or microlithography, for instance. This means even higher reliability, security and efficiency for customers and applications. Hartmann was awarded the 2013 SCHOTT R&D Prize for his work.
Optics expert Dr. Peter Hartmann received the SCHOTT R&D Prize for developing a model for precisely predicting the strength of ZERODUR® glass-ceramic.
Due to their strong atomic bonds, glass and glass-ceramic materials theoretically resist high bending stress. In reality, however, these capabilities deteriorate quite considerably under stress. This can be attributed to microcracks in the surface, which, if deep enough, can lead to breakage and thus complete component failure. It is therefore all the more important for developers and engineers to gain a more accurate understanding of the strength of components in more difficult applications. Ideally, the probability of failure under maximum stress is to be minimized as much as possible.
The technology group SCHOTT is capable of providing customers with detailed information on the strength and service life of mechanical and optical components made of the temperature resistant ZERODUR® glass-ceramic. Accurate predicting of component strength is possible using a new scientific approach taken by optics expert Dr. Peter Hartmann, who has been awarded the SCHOTT R&D Prize. His work proves that the conventional approach for determining the strength of glass and glass-ceramic, the so-called "two-parameter Weibull distribution," no longer suffices, rather it needs to be enhanced by a modified approach. This approach provides a minimum strength value for defined surface conditions and enables the calculation of the service life under specified stress while considering material fatigue under stress. Yet another advantage: this model reduces statistical uncertainties and allows for considerably higher mechanical stresses to be applied to ZERODUR® components than in the past.
"This work documents a high degree of scientific and technical professionalism and demonstrates the outstanding material and technological expertise SCHOTT has," explained SCHOTT Board member Dr. Hans-Joachim Konz at the award ceremony. "Furthermore, this work underscores our goal of offering benefits to our customers through our profound understanding of materials. This is thus an example of the successful link between science on the one hand and technical marketing on the other," he adds.
