Electric Field-Assisted Ion Exchange of Borosilicate Glass Tubes [chapter]

Ali Talimian, Vincenzo M. Sglavo
2015 Ion Exchange - Studies and Applications  
In this work, DC electric field-assisted ion exchange was carried out to enhance the sodium-potassium inter-diffusion and improve the mechanical performance of borosilicate glass. Electric fields with intensity varying between 100 V cm -1 and 3000 V cm -1 were applied in both direct and inverted polarizations. Four point bending test and the Vickers indentation method were used to characterize the mechanical properties. Energy dispersion x-ray spectroscopy was carried out to determine the
more » ... ium concentration within the surface layers of the samples. The analysis of the potassium concentration profile near the surface shows that the external electric field governs the ion exchange process and it is possible to send potassium ions down to a depth of 45 µm in only 5 min. By plotting the electrical current versus time, it is revealed that the process stops after a certain saturation time. Vickers indentation measurements show that the compressive residual stress in the samples treated under electrical field is 3 times higher than that obtained by conventional chemical tempering. The bending strength of samples prepared by reversing the field direction is higher than that measured in specimens treated only on one side due to the symmetrical distribution of the stress on both sides.
doi:10.5772/60805 fatcat:5t2v7ksiwfgzrchxg5jo3ckvva