Fraunhofer Institute for Mechanics of Materials IWM
Fraunhofer Institute for Mechanics of Materials IWM

Developing complex bending processes

© Fraunhofer IWM, Photo: Kai-Uwe Wudtke

Biegeversuche von Flachglas Vorspann-Flachglas nach 3-Punkt-Biegebelastung bis zum Crash. Mit einer Walze wird das Flachglas gebogen bis zum Bersten - die zentrale Stelle, von der die Risse ausgehen, liegt neben der Walze.

Damage analyses of brittle materials

© Fraunhofer IWM

Spannungsoptik Glasplatte mit Sandra Mee.

Mastering the manufacture and use of brittle materials

© Fraunhofer IWM, Photo: Achim Käflein

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Accurate separation cracks in thermal processes

© Fraunhofer IWM, Photo: Kai-Uwe Wudtke

Zwei mit kleinem Biegeradius um 90° gebogene Flachgläser, Anordnung wie in einer Isolierglasscheibe: 12 mm Abstand.

Laser-assisted glass-bending processes for precise bending radii

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Glass Forming and Machining

We are specialists in glass, ceramics and semiconductor materials. Our core competencies lie in fracture-mechanical analysis methods and manufacturing processes with a focus on hot glass forming, ultra-precision processing, joining techniques and special separation and cutting techniques. A particular focus is placed on edge-bonding techniques for vacuum-insulating glass, low-damage machining techniques for precise contours in precision components, as well as separation techniques for sheets of laminated glass. Our findings lead to solutions for new processes and products and to the informed assessment of their cost-effectiveness and feasibility in industrial use.

What we offer

 

  • Process development: separating and bending plate glass, hot forming processes, wire cutting for silicon, edge-bonding techniques for vacuum-insulating glass
  • Ultra-precision processing of molding tools
  • Process analyses for solar cell production to prevent damage and increase yield
  • Low-damage silicon separation
  • Damage analyses for glass and silicon
  • Supporting the process and its assessment through simulations

Topics

 

© Fraunhofer IWM

Bending glass


We develop solutions for the representation of complex forms made of flat glass products. With Fraunhofer IWM's technology, unmatched small bending radii can be realized within tight tolerances, and flat partial surfaces retain the excellent surface quality of the flat glass product, allowing for contours made of glass to be created with very high precision. New manufacturing processes and demands from designers and users alike have led to the increasing...

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© Fraunhofer IWM, Photo: Kai-Uwe Wudtke

Cutting glass


Conventional cutting processes, such as scribing and breaking glass, create microcracks in the fractured edge. In contrast, the thermal cutting process developed at Fraunhofer IWM enables a fractured edge with fewer and smaller defects. The use of a laser facilitates the introduction of heat into the glass with temporal and spatial precision. In this way, the separation crack is guided through the glass with contour precision by local stresses...

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© Fraunhofer IWM, Photo: Achim Käflein

Forming glass


We develop solutions for the hot forming of components made of glass. Discrete components are depicted in a pressing process (blank presses). Structures with optical or haptic functions, for example, are introduced into larger components using a local embossing process (hot stamping). Both processes are characterized by short process cycles, high surface quality and contour accuracy. Consequently, optical components...

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Joining glass


We develop joints which account for the chemical, thermal and mechanical properties of glass as a material. To this end, we functionalize glass surfaces using specially developed multilayer coatings, evaluate brazing materials and adapt the process parameters. Our goal is to match the base material, solder material and process control in such a way that a dimensionally stable and vacuum-tight joint can be created. As a result, the strengths of vacuum-insulating glass used in windows...

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Numerical simulation

 

Glass-forming processes are thermal processes and take place at temperatures above 400 °C. During these processes, the impact of forces in addition to temperature causes the geometry of the component to change incrementally. The material states change continuously until the final properties are reached at the end of the process in the cold state. A wide range of extensive tests can be carried out on the cold component, but this is not possible while the process is taking place.

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Brittle materials: assessment, durability, design, damage analyses

 

We analyze and characterize damage and material failure in glasses, ceramics and semiconductors. In doing so, we identify weak points in the material or (glass) composite. By looking for relevant stresses along the entire process chain as far as damages during use, we can identify critical manufacturing steps and recommend effective measures to avoid the causes of material failure. With our results, we provide solutions for new processes and products as well as...

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© Fraunhofer IWM, Photo: Achim Käflein

Facilities

 

Our facilities offer a wide range of possibilities for glass analysis, processing and shaping. Here, in addition to the institute’s resources, we have further special equipment at our disposal for glass as a material.

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Our range of services in compact form

Failure analysis in brittle materials
Bending of flat glass
Localized hot embossing of glass for innovative user interfaces
Severing of glass, flat glass, laminated safety glass and hollow glass
Glass-metal soldered joints

Machining Processes, Glass Forming publications

 

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Contributions to scientific journals, books and conferences as well as dissertations and project reports...

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