Glass - Back to the Future!

Presenting Author:
Norfadhilah Ibrahim

article posted 4 April 2016

Norfadhilah Ibrahim is a third year student at The University of Sheffield. Under supervision of Prof Russell J Hand. The focus of her study is on Boroaluminoslicate glasses- Effect of composition on mechanical properties.

Impact of different amount of alkaline earth on the properties of boroaluminosilicate glass

N. Ibrahim*& R. J. Hand
Department of Materials Science and Engineering, University of Sheffield, Sir Robert Hadfield Building, Mappin Street, Sheffield, S1 3JD, United Kingdom

Boroaluminosilicate glasses are very interesting due to their complicated structural speciation involving two glass formers and one conditional former. It is also well known that when alkali oxide network modifiers, such as Na2O are present in a glass, it enables alumina to act as network former rather than as a modifier. Such alkali additions can also lead to the formation of tetrahedral boron. In boroaluminate glass, the addition or substitution of alkaline earth such as Ca and Ba in glass give different structural outcomes. We report data obtained on two different series of boroaluminosilicate glasses. In both of them, alumina is exchanged by alkaline earths. Series 1 glasses as shown in Figure 1 contain 10 mol% of sodium (10Na2O.10B2O3.(20-w)Al2O3.wX.60SiO2w (N15B10A20wXwS60) where X=BaO and CaO with w=25, 5, 75 while the series 2 glasses contain 15 mol% sodium (15Na2O.10B2O3.(15y)Al2O3.yZ.60SiO2 (N15B10A15yZyS60) where Z=BaO and CaO with y=75, 10, 125). Fourier transform infra-red and Raman spectroscopies have been used to investigate the structural changes arising from the alkaline earth additions. Thermal, physical and mechanical property evaluation has also been conducted.

Figure 1: Structural and physical properties of Series 1 glasses (a) Fourier transform infra-red (b) Raman band (c) Glass transition temperature (d) Density