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Method for determining temperature- or stress-dependent changes in physical quantities of glass

A technology of physical quantity and glass, applied in the direction of measuring devices, investigation phases/state changes, testing of machines/structural components, etc.

Active Publication Date: 2018-06-12
SCHOTT AG
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

In addition, the rate of temperature change during operation ranges from <0.17K / h, thus much smaller than the typical measured rate of 36K / h

Method used

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  • Method for determining temperature- or stress-dependent changes in physical quantities of glass
  • Method for determining temperature- or stress-dependent changes in physical quantities of glass
  • Method for determining temperature- or stress-dependent changes in physical quantities of glass

Examples

Experimental program
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Embodiment Construction

[0063] Within the glass transition range (transition temperature T as defined in ISO 7884-8 g Nearby) the mathematical modeling of atomic structure relaxation and stress relaxation is known and used in the mathematical modeling of thermomechanical processing methods of glass in the glass manufacturing and processing industries. Implement the model in FEM calculation software (such as ANSYS). From O.S.Narayanaswamy, "A model of structural relaxation in glass", J.Am.Ceram.Soc.54, 491-498 (1971), it is known that the glass transition temperature T g A range of models that describe these structural relaxations with sufficiently good modeling quality. Structural relaxation is viewed as a transition from a non-equilibrium state of the glass structure to an equilibrium state (atomic rearrangement process).

[0064] Glasses are distinguished by the fact that non-equilibrium states can solidify. Depending on the thermal conditions (fast / slow cooling), the glass solidifies in differe...

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PUM

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Abstract

The present invention relates primarily to the manufacture or provision of glass or glass-ceramic articles. The present invention is based on the object of making it possible to provide glass or glass-ceramic articles with very precisely characterized thermomechanical properties. For this purpose, the deformation of the glass or glass-ceramic material is determined as a function of time at least twice at different rates of change of temperature or mechanical stress. Based on the measurements, relaxation times and weighting factors are determined by modeling. Then, based on the relaxation times and weighting factors related to the distribution of the relaxation processes occurring in the product, temperature-dependent or stress-dependent changes in the time delay of physical quantities such as thermal expansion or refractive index are included as part of a predefined temperature change or stress change. Function Compute. The present invention is used to select suitable glass articles exhibiting selected time delay properties during manufacture.

Description

technical field [0001] The present invention generally relates to the manufacture or provision of glass or glass-ceramic articles. More specifically, the present invention relates to a method enabling the characterization, production and / or selection of glass and glass-ceramic articles on the basis of precisely defined thermomechanical properties. Background technique [0002] Special glass and glass-ceramic articles developed and manufactured in a custom-made manner for specific applications set very different requirements, due to the different requirements of the specific application for thermo-mechanical quantities such as thermal expansion and structural relaxation, manufactured glass or glass-ceramic components The stated requirements must be met. Examples of such custom products include telescope mirror substrates and components made of glass ceramics for microlithography. [0003] Glass ceramics exhibit low thermal expansion in different application temperature rang...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): G01N25/02G01N33/38G01M11/08
CPCG01N25/02G01N33/386G01M11/005G01N19/00G02B1/00G02B5/08
Inventor 拉尔夫·让达齐克克里曼斯·库尼施思罗夫·约翰逊
Owner SCHOTT AG