Production of fluorine-doped silica bodies using the optimized Vi-Si-HIP manufacturing process from the combination of viscous sintering and gas phase fluorination with subsequent hot isostatic pressing

A new manufacturing process aims to optimize the production of fluorine-doped glass in terms of energy efficiency. The green bodies are produced from nanoscale powders in a wet-chemical process and sintered at low temperatures in a fluorine-containing atmosphere. The green body composition and the sintering parameters such as gas atmosphere, temperature and feed rate are important for the resulting fluorine concentration and glass formation. The subsequent hot isostatic pressing leads to complete compaction of the sintered bodies and the associated increased transmission. By recompressing the samples, the sintering temperature can be lowered, thereby reducing the defluorination process at high sintering temperatures.