Obtaining Ultra-High Hardness in Spark Plasma Sintered Ge40As40Se20 Bulk Glass

Abstract

We performed mechanical milling and Spark Plasma Sintering technology to fabricate a high Ge content chalcogenide glass, the Ge40As40Se20 glass, which locates outside the Ge-As-Se glass-forming domain. By using the optimal ball milling time of 50 h and sintering stress of 37.5 MPa, the large size Ge40As40Se20 bulk glasses were obtained, which possesses both large Vickers hardness of 369 Hv and relative high optical transmission of 43% (@5 and 9 μm). Moreover, it was found there are pores in the sintered glasses more or less, and the pore size and number significantly affect transmission, i.e., the optimal Ge40As40Se20 bulk glasses were demonstrated has the smallest and least pores. The combination of mechanical milling and low-temperature sintering methods has been confirmed to improve the glass formability and then obtain the high Ge content component with a potential high hardness glass to break through the limited mechanical property of chalcogenides.

Keywords: chalcogenide glasses, vickers hardness, spark plasma sintering, mechanical milling.