Research On Molding Process Of Chalcogenide Glass

Chalcogenide glass is a new type infrared material with good cost performance, which can be processed into variant needed shapes by molding process. So it attracts much attention in IR industry and plays a key role in micro-optical element manufacturing. The study on molding process of chalcogenide glass is still in the initial stage and simulation analysis of molding process of chalcogenide glass has never been reported before, so it is very important to study its thermal mechanical properties and analyze its imprint characteristics. The details of our study are described as follows.The details of our study are described as follows.Thermo-mechanical properties (creep response) of chalcogenide glass are measured, and the viscoelastic material model is set after fitting the obtained data. Then different geometry models are structured to study the filling mechanism. In this paper the templates of rectangular channel is used to study the effects of molding temperature, force and time on molding process. The chalcogenide glass'flow morphology during imprinting is obtained. The filling effect of different geometry and dimension of templates are analyzed. The internal stress distribution of chalcogenide glass under three-dimensional conditions is studied. The main ejection defects during experiments are described. The stress distribution during de-molding and the influences on de-molding defects are studied.The results showed that it's feasible to use finite element analyses to study the molding process of chalcogenide glass. The chalcogenide glass showed obvious viscoelastic material properties under molding temperatures and the elastic modulus would reduce at least 5 orders. The filling ratio of mold cavity could reach to 97.2% under the optimized three main parameters (force 30N, temperature 480℃, and time 1800s). The imprinting depth increased with the increment of the mold duty ratio and the substrate aspect ratio, but decreases with the increment of mold aspect ratio. There were three different stress distribution areas when different mold shapes were used. Obvious stress relaxation during imprinting was observed, and stress value would reduce from 29.4Mpa to 13.1Mpa at non-concentration areas and from 2190Mpa to 677Mpa at concentration areas.