SPP 1594:  Topological Engineering of Ultra-Strong Glasses

• Subject Area: Materials Science and Engineering
• Term: from 2012 to 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 198574154

Accepting brittleness and benefiting from their optical properties and universal processability, glassy materials have found their traditional applications in environments with low levels of tensile stress. It was recognised, however, that intrinsically glasses represent the strongest man-made material, which can be produced on large-scale. Only for low resistance to surface damage, the uniquely high levels of intrinsic strength can presently not be made use of. In a broader context, covering all classes of disordered materials (distinguished by the nature of chemical bonds), brittleness, stiffness, elastic limit and the practical absence of ductility originate from their molecular, mid-range and surface topology. In inorganic as well as metallic glasses and in contrast to any other solid material, mechanical properties must be considered in a twofold way: on the basis of structural length scales and dynamics. Identification of determinant topological and density constraints and their engineering towards ultrahigh toughness is now seen as the major future breakthrough of the field. As to yet disregarded synergy arises from the joint treatment of both classes of glass: from a topo-mechanical view, both materials appear to follow the same constitutive principles of coordination, packing density, free volume, structural dynamics, structural heterogeneity and extreme mid- to long-range homogeneity. The Priority Programme has the objective to condense existing experimental and theoretical competencies within Germany to enable a conceptual breakthrough in the understanding and design of the mechanical properties of glasses. For the first time, inorganic and metallic glasses will be considered in a joint context. Key to topical success, international visibly and long-lasting impact is the effective coordination of this effort for which a number of central activities are planned, including the organisation of national and international workshops and conferences, the promotion of young researchers, equal opportunity actions, setting-up a mentoring programme and ensuring high-impact outreach and networking.

• DFG Programme: Priority Programmes
• International Connection: Greece, India, Russia

Projects

• Coordination Funds (Applicant Wondraczek, Lothar )
• Impact of structure and relaxation on fatigue and micromechanical properties of oxide glasses - the role of volatiles and bonding state (Applicants Behrens, Harald ;  Deubener, Joachim ;  Müller, Ralf )
• Influence of glass topology and medium range order on the deformation mechanisms in borosilicate glasses, a multiple length scale approach (Applicants Durst, Karsten ;  Fuhrmann, Sindy ;  de Ligny, Dominique )
• Influence of Topological Anisotropy on the Mechanical Properties of Silicate Glasses (Applicants Bitzek, Erik ;  Spiecker, Erdmann ;  Wondraczek, Lothar )
• Kinetic and structural properties of shear bands in bulk metallic glasses (Applicant Wilde, Gerhard )
• Mechanical Properties of Oxide Glasses at Constraint Gradients (Applicants Deubener, Joachim ;  Wondraczek, Lothar )
• Microscopic mechanisms of shear band formation in bulk metallic glasses (Applicants Horbach, Jürgen ;  Wilde, Gerhard )
• Model for the prediction of thermomechanical bulk properties of multicomponent oxide glasses based on a combined quantum mechanical and thermodynamic approach (Applicants Conradt, Reinhard ;  Dronskowski, Richard )
• Nanoglasses - A way to enhanced mechanical properties of amorphous materials (Applicants Albe, Karsten ;  Hahn, Horst )
• Quantum mechanically guided design of ultra strong and damage tolerant glasses (Applicants Dehm, Gerhard ;  Raabe, Dierk ;  Schneider, Ph.D., Jochen M. )
• Stabilising elements in high oxygen coordination numbers: topo-structural implication on glass strength (Applicants Brauer, Delia ;  de Ligny, Dominique ;  van Wüllen, Leo )
• Stress corrosion and corrosion fatigue of Zr-based bulk metallic glasses (Applicant Gebert, Annett )

• Spokesperson: Professor Dr.-Ing. Lothar Wondraczek