The Relations Between the Mechanical Properties and the Nano Crystalline in Chalcogenide Glass System

Chalcogenide glass lens have been attracted because of excellent optical properties and low cost fabrication methods, i.e., glass molding press. Molded glass lens should have unique thermal, optical and mechanical properties in order to be applied to molding process. One of the weaknesses of chalcogenide glass lens has low hardness relatively compared with crystalline lens. In order to improve the mechanical properties, the chalcogenide glass samples were thermally treated leading to form nano crystalline phase. The relations between mechanical properties and nano crystalline phases were studied. The nano crystalline phase were controlled with the thermal treatment condition and confirmed.by scanning electron microscopy and x-ray diffraction. The hardness was characterized by a Knoop hardness tester. The transmission properties according to thermal treatment condition were characterized by FT-IR spectrometer. Finally, the chalcogenide glass system after optimized thermal treatment shows approximately 10% of increase in hardness as well as above 56% average transmittance in the range of 8~12 microm.