Glass Ceramics and Thermal Analysis

High-temperature durability and reliability are key factors in manufacture and application of advanced ceramics and glasses. Thermo-mechanical relaxation phenomena, crystallisation, sintering, and the concentration and mobility of volatiles (e.g. hydrogen, water, carbon gases, oxygen) are of importance within that context. We try to improve basic preconditions for the reliable use of advanced glassy and crystalline materials by means of problem- and technology-oriented development, adaptation and cross linking of thermal testing methods within the scope of internal and external co-operations.

Fields of expertise and equipment

Glass synthesis und characterisation

• Glass melting furnaces
• Pressure chamber- and vacuum furnaces
• Glass powder milling
• Glass preparation
• Optical refractometer
• UV-VIS / NIR-spectrometer

Thermal analysis and thermally induced degassing

• Vacuum-hot-extraction with mass spectrometer detection of evolved gases, high temperature viscosimeter and -dilatometer, differential thermal analyser, differential thermal gravimeter with mass spectrometer gas detection, large capacity differential thermal gravimeter, dynamic mechanical thermal analyser

Ceramic layers and colloidal SiO₂ - and Al₂O₃ suspensions

• Sol-gel-synthesis, spin- and dip-coating, rheometer, photon correlation spectrometer, particle size analyser

Crystallisation and sintering

• Gradient furnaces, vacuum and glove box furnaces, hot stage microscopes, vertical dilato­meter, optical and interference microscope, load-defined vertical dilatometer

Current research

• Hydrogen in fused silica (left figure)
• Ceramic protection layers from Al₂O₃ sol-suspensions (right micrograph)

The rate of hydrogen degassing from fused silica during heating

Protecting nano-crystalline Al₂O₃-layer, coated on an corundum substrate by dip-coating of Al₂O₃-sol- suspensions (layer thickness: ca. 1 µm; FIB-cut and TEM-micrograph BAM, 5.1)

• Water in silicate glasses and melts
• Sintering of glass matrix composites
• Gas sensor controlled precursor debindering

top