| Chalcogenide glass has been widely applied in infrared technology over the past few decades due to the excellent stability of chemistry, the higher non-linear optical and the lower cost. However, because of the inhomogeneity of chalcogenide glass with large size and the behind investigation of precision molding and rapid prototyping technology, the enhancement of infrared technology application was seriously limited in our country.In the present work, the vertical homogeneity, radial homogeneity and the influence of the nucleating agent (RbI) on the homogeneity of chalcogenide glass Ge23Se67Sb10 were primarily investigated by using XRD, FT-IR, DSC, density and microhardness tests. On the bases, a method was proposed to improve the homogeneity of chalcogenide glass. Furthermore, the influence of temperature and nucleating agent (CsCl) on the creep properties of chalcogenide glass Ge23Se67Sb10 above the softening point were investigated through the TMA. The electronic universal testing machine was used to test the influence of temperature and strain rate on stress-strain curve of Ge23Se67Sb10 glass in the compressing process. Finally, the sample of chalcogenide glass was molded practically, and the quality of products in different conditions was compared. The results are as follows:(1) The homogeneity of rod chalcogenide glass depends on the sample diameter. When glass diameter was small, infrared transmittance, density and hardness increased gradually from top to bottom, while the characteristic temperature barely changed. The internal and external cold speed gradient increased with the increasing of diameter. Therefore, the difference of performance was obvious on the radial, and comprehensive performance of external was better than internal. RbI doping and salt bath cooling could optimize the homogeneity. After adding nucleating agent RbI, the hardness was increased as a whole, but infrared transmittance decreased more than 60%. The resistance to crystallization weakened and the temperature of starting crystallization has been decreased by 40 ℃ than without nucleating agent. In order to effectively improve the homogeneity of large size glass, the salt bath cooling was proposed to prepare glass according to the characteristic of salt bath. The result showed that the salt bath cooling was an effective method to improve the homogeneity of large size chalcogenide glass.(2) Nucleating agent CsCl had a significant impact on the glass softening point and creep behavior of chalcogenide glass Ge23Se67Sb10. The paper designed a simple test device basing on the definition of glass softening point. The softening point of Ge23Se67Sb10 glass was 301 ℃, and decreased about 10 ℃ after the addition of 5% CsCl. The creep property of the chalcogenide glass increased firstly, and then decreased with increasing of CsCl content. The least square nonlinear curve was used to fit the creep curve. It was found that the viscoelastic properties of sample was accord with Burgers model, and the viscoelasticity parameters of glass were obtained in different conditions. The deformation of the sample changes most quickly and reaches the fastest constant when the content of CsCl was 2%. High temperature compress experiment demonstrated that chalcogenide glass Ge23Se67Sb10 was sensitive to temperature and strain rate. The lower the temperature or the greater the strain rate is, the larger the stress is.(3) The molding temperature and holding time would affect the quality of products. After being pressed at 320 ℃ for 30 min, the molded sample was the best when the pressure was 30 kN. Its surface was bright. But the infrared transmittance was lower than that of samples without molding. However, the infrared transmittance was improved after polishing, reaching about 50% in 8～12 μm bands. |
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