Addition Of P2O5 To Sio2-Al2O3-B2O3-Mgo-Cao-Na2O Glass: A Study Of Its Effects On Glass Properties, Structure & Melting Behaviour

The effects of weight-for-weight partial replacement of SiO2 by P2O5 have been investigated in glass compositions in the system SiO2-Al2O3-B2O3-MgO - CaO-Na2O, similar to the composition of commercial E-glass. Samples with analysed P2O5 contents of 0, 2.6, 4.6 & 6.8wt% (0,1.2,2.1 & 3.2 mol%) have been produced. Homogeneous glasses are formed at 0 & 2.6wt% (0 & 1.2mol%) P2O5. A crystalline fluorapatite phase has been identified in samples containing 4.6 & 6.8wt% (2.1 & 3.2mol%) P2O5. The introduction of Ca3(PO4)2 as a batch material has no distinguishable effect on batch melting behaviour at levels providing up to 4.6wt% (2.1mol%) P2O5, when melted at 1435C. Incomplete melting of the highest Ca3(PO4)2 content batch caused damage to Pt alloys.