Fiber Reinforced Transparent Glass

The presentation deals with different (matrix) glasses reinforced with coated Nextel® 440 fibers. The mechanical properties of the composite materials depend strongly on the thermal expansion difference between matrix and fiber and on the type of fiber coating. A fiber pull-out during loading is desired in order to get a damage tolerant behaviour. But not each from the mechanical point of view successful fiber/matrix pair is suitable for a transparent composite. Such a transparent composite demands fibers and a matrix glass with adapted refractive index, without internal stress and holes, and a fiber coating which does not influence the optical transmission in the visible wavelength range. The Nextel® 440 fiber (produced by 3 M) and the code 8650 matrix glass (produced by Schott) are fitted components. The coating should be a double layer for sliding and protecting. Moreover a hot pressing process in oxydizing atmosphere is helpful.