摘要:
The present disclosure is directed to a method for producing constancy of the ion-exchanged product stress profile through adjustment of ion-exchange conditions by taking account of the influence of salt bath poisoning on the bath's useful lifetime. The present disclosure is directed to a method of ion-exchange in which the salt bath temperature and salt bath time are adjusted as a function of the amount of alkali metal ions that exchange in the bath. That is, temperature and time are adjusted as a function of salt bath poisoning. Temperature is set to its highest value and time to its shortest value in the starting unpoisoned salt bath, those values chosen to hit target values of surface compressive stress and exchange depth of layer. Temperature is then reduced and time lengthened as salt bath poisoning proceeds, those changes chosen to maintain the same surface compressive stress and exchange depth of layer.
摘要:
The present disclosure is directed to a method for producing constancy of the ion-exchanged product stress profile through adjustment of ion-exchange conditions by taking account of the influence of salt bath poisoning on the bath's useful lifetime. The present disclosure is directed to a method of ion-exchange in which the salt bath temperature and salt bath time are adjusted as a function of the amount of alkali metal ions that exchange in the bath. That is, temperature and time are adjusted as a function of salt bath poisoning. Temperature is set to its highest value and time to its shortest value in the starting un-poisoned salt bath, those values chosen to hit target values of surface compressive stress and exchange depth of layer. Temperature is then reduced and time lengthened as salt bath poisoning proceeds, those changes chosen to maintain the same surface compressive stress and exchange depth of layer.
摘要:
In a method of making a glass sheet using an overflow fusion downdraw process, a glass sheet quality metric level Q1 is selected, where Q1 is a measure of allowable retardation in the glass sheet. A glass ribbon temperature T1 at which a potential glass ribbon thermal artifact could occur in a glass ribbon while the glass ribbon is being drawn through a drawing machine enclosure is identified. A thermal artifact envelope E1 is determined, where E1 contains types of glass ribbon thermal artifacts allowable at T1 and Q1. A glass melt is overflowed from an isopipe to form a glass ribbon at the root of the isopipe. The glass ribbon is drawn below the root of the isopipe through the drawing machine enclosure to form the glass sheet. The drawing machine enclosure is altered at a location corresponding to where the glass ribbon would be at T1 such that during drawing of the glass ribbon the potential glass ribbon thermal artifact is not formed in the glass ribbon at T1 or, if the potential glass ribbon thermal artifact is formed in the glass ribbon at T1, the potential glass ribbon thermal artifact is within E1.
摘要:
A method of making a strengthened glass article. The method includes altering the glass structure and subsequently creating a compressive layer extending from the surface of the glass to a depth of layer. In some embodiments, the structure is altered by heat treating the glass at a temperature that is less than the annealing point of the glass, and the compressive layer is formed by ion exchange. A strengthened glass article made by the method is also provided.
摘要:
Disclosed are synthetic silica glass having a low polarization-induced birefringence, process for making the glass and lithography system comprising optical element made of the glass. The silica glass has a polarization-induced birefringence measured at 633 nm of less than about 0.1 nm/cm when subjected to excimer laser pulses at about 193 nm having a fluence of about 40 μJ·cm−2·pulse−1 and a pulse length of about 25 ns for 5×109 pulses.
摘要:
A magnetic photonic crystal for providing asymmetry of spatial frequencies in the propagation of light is provided. The crystal is formed from at least two materials having different indices of refraction which are aligned along the longitudinal axis of the crystal. And arranged in an array whose symmetry does not include a spatial inversion operator such that (x,y)==/=(−x,−y). One or more of the materials forming the array is magnetic such that the magnetic group representation of the array does not include time inversion as a symmetric operator. In operation, when the magnetic material forming the material is magnetized, the group velocity property of light propagated in one direction along the axis of the array is different from the group velocity property of light transmitted in an opposite direction through the array. The magnetic photonic crystal may be used, for example, as an optical memory device or a high speed modulator/demodulator.
摘要:
A method of making a strengthened glass article. The method includes altering the glass structure and subsequently creating a compressive layer extending from the surface of the glass to a depth of layer. In some embodiments, the structure is altered by heat treating the glass at a temperature that is less than the annealing point of the glass, and the compressive layer is formed by ion exchange. A strengthened glass article made by the method is also provided.
摘要:
Computer-implemented methods and apparatus are provided for predicting/estimating (i) a non-equilibrium viscosity for at least one given time point in a given temperature profile for a given glass composition, (ii) at least one temperature profile that will provide a given non-equilibrium viscosity for a given glass composition, or (iii) at least one glass composition that will provide a given non-equilibrium viscosity for a given time point in a given temperature profile. The methods and apparatus can be used to predict/estimate stress relaxation in a glass article during forming as well as compaction, stress relaxation, and/or thermal sag or thermal creep of a glass article when the article is subjected to one or more post-forming thermal treatments.
摘要:
In a method of making a glass sheet using an overflow fusion downdraw process, a glass sheet quality metric level Q1 is selected, where Q1 is a measure of allowable retardation in the glass sheet. A glass ribbon temperature T1 at which a potential glass ribbon thermal artifact could occur in a glass ribbon while the glass ribbon is being drawn through a drawing machine enclosure is identified. A thermal artifact envelope E1 is determined, where E1 contains types of glass ribbon thermal artifacts allowable at T1 and Q1. A glass melt is overflowed from an isopipe to form a glass ribbon at the root of the isopipe. The glass ribbon is drawn below the root of the isopipe through the drawing machine enclosure to form the glass sheet. The drawing machine enclosure is altered at a location corresponding to where the glass ribbon would be at T1 such that during drawing of the glass ribbon the potential glass ribbon thermal artifact is not formed in the glass ribbon at T1 or, if the potential glass ribbon thermal artifact is formed in the glass ribbon at T1, the potential glass ribbon thermal artifact is within E1.
摘要:
Methods are provided for reducing the dimensional changes of a glass substrate during a display manufacturing process. The reductions are achieved by increasing the fast relaxation exhibited by the glass. Test methods are provided for distinguishing the effects on dimensional changes of fast relaxation versus slow relaxation. Glass substrates which exhibit reduced dimensional changes during critical thermal cycles of display manufacturing processes are also disclosed.