Sintering Process of Chalcogenide Glass Powder using Powder Metallurgy and Spark Plasma Sintering

Abstract

Chalcogenide glasses and glass-ceramics have presented a high interest for the production of lenses transparent in the 3-5 μm and 8-12 μm windows replacing the expensive single crystalline Ge or polycrystalline ZnSe or ZnS for infrared (IR) lenses. It is competitive in terms of cost effectiveness and mass production. Among various chalcogenide glass forming systems, ternary Ge-Sb-Se chalcogenide glass is one of the promising the materials for long wavelength infrared (LWIR) range, i.e, 8-12 μm. It has thermal and mechanical stability and extended infrared transmittance up to 15 μm. Chalcogenide glass components are generally prepared by conventional melt-quenching method in sealed silica ampoules. Those ampoules are expensive and not reusable and its low thermal conductivity limits the dimensions of samples and reduces the glassy domain. Whereas glass can be fabricated by sintering of amorphous glass powders. Fabricating glass components using sintering can reduces the processing time, temperature and cost and control crystallization for glass ceramics. Research on powder metallurgy (P/M) process and spark plasma sintering (SPS) for chalcogenide glass powder processing has been investigated in this work. The sintering parameters are the key factors to obtain a high quality glass since they determine the optical and mechanical properties. Effects of sintering parameters such as temperature, dwell time and heating rate were investigated. As a raw material, ternary Ge-Sb-Se chalcogenide glass powder was used in this work. Mechanical and optical properties of sintered chalcogenide glasses fabricated by both P/M and SPS were analyzed about density, micro structure, crystal structure, Vickers hardness and transmittance compared to melt-quenched samples. The result showed promising advantages of cost-effectiveness and potentials for various application fields from LWIR lenses to porous structures, glass-ceramics, and sensor fields.