About this Abstract |
Meeting |
MS&T22: Materials Science & Technology
|
Symposium
|
Glasses and Optical Materials: Current Issues and Functional Applications
|
Presentation Title |
Continuation of the Investigation of Double Ion-exchange in Mixed Alkali-lime Silicate Glasses |
Author(s) |
Jacob Kaspryk, William LaCourse |
On-Site Speaker (Planned) |
Jacob Kaspryk |
Abstract Scope |
A two-step chemical strengthening process in mixed alkali-lime silicate glasses was investigated. Mixed alkali 15(Na<sub>2</sub>O + R<sub>2</sub>O ) 10CaO 75SiO<sub>2</sub>, where R is Li or K, were first exchanged above T<sub>g</sub> in a Li<sup>+</sup> containing salt bath. This was followed by a second exchange or at temperatures well below the strain point of the original glass. The initial ion-exchange (Li for Na and K) leads to complex alkali profiles when K<sup>+</sup> is present, however the overall alkali composition changes due to exchange extending to depths greater than 50 microns for treatment times less than 1 hour at temperatures in the range of 550 - 600℃. This previously produced strengths from 197-244 MPa. The second ion-exchange (Na for (Li and K) or K for (Li and K)) allowed the formation of a compressive layer for strengthening, however this leads to complex profiles due to unequal diffusion rates of K<sup>+</sup> and Na<sup>+</sup>. |