The glass formation and crystallization studies on iron phosphate–silicate glasses

Abstract

The assessment of impact of incorporation of various amount of Fe 2 O 3 at the expense of MgO and CaO on the glassy phase formation and thermal stability exhibited in P 2 O 5-SiO 2-K 2 O-MgO-CaO-Fe 2 O 3 system was carried out. The characteristic temperatures for iron phosphate-silicate glasses and glass-crystalline materials were designated from associated DSC curves. Selected samples were subjected to the process of induced crystallization, and products combined with particular exothermic effects were identified. Combination of DSC, XRD and SEM-EDS methods enabled to collect invaluable data concerning the course of crystallization of not only iron phosphate-silicate glasses subjected to the process of induced crystallization, but also glass-crystalline materials obtained directly through melt-quenched technique. The amount of particular crystalline products associated with selected devitrificates was determined via Rietveld technique. Results of the conducted study indicated that Fe 2 O 3 addition conduces to the decrease in crystallization temperatures and thermal stability which was reflected in calculated values of DT and K W parameters. Concomitantly, glass with 20 mol% iron (III) oxide addition exhibited significantly improved, distinctive thermal stability among the materials in the analyzed series. The connection of crystalline phases with gradual alterations in polymerization degree of glass matrix was also established. The performed study is a contribution to the knowledge of iron phosphate glasses family and associated glass-crystalline materials. Keywords Glass-forming ability Á Crystallization process Á Fe 2 O 3 Á Iron phosphate-silicate glasses & Justyna Kuczek

Crystallization and Thermal Stability of the P-Doped Basaltic Glass Fibers

“…The thermal analysis data allow us to make the assumption that the most thermally stable sample is a sample containing 2 wt % phosphorus oxide. The glass transition temperature of P-BS2 varies slightly, which corresponds to literature data [21,22]. At the same time, the position of the exothermal peak corresponding to the crystallization process shifts to the higher temperature ( Figure 6).…”

“…Iron phosphate glasses are commonly characterized by O/P ratio indicating whether orthophosphate, pyrophosphate or metaphosphate units prevail in the structure [21,22]. Authors studied the mutual influence of the components in the P 2 O 5 -SiO 2 -K 2 O-MgO-CaO-Fe 2 O 3 system in detail.…”

Using of wastes from the enrichment of quartz-feldspar raw materials in the production of porcelain stoneware

“…The presence of a glass phase makes it possible to form a homogeneous strengthened crystalline structure with submicron grain size [24,25]. The formation of small needlelike crystals of mullite with a size of 1.5-3.5 μm contributes to the production of dispersionstrengthened materials [26,27]. The study of the melting of ceramic masses made it possible to establish that the proposed ceramic mass (Fig.…”

Unveiling Non-isothermal Crystallization of CaO–Al2O3–B2O3–Na2O–Li2O–SiO2 Glass via In Situ X-ray Scattering and Raman Spectroscopy

“…The small exothermic peak, prior to the melting peaks is most probably connected with a small fraction of less perfect crystals formed after crystallization. These events, seen in multicomponent glasses, indicate incomplete crystallization before melting. This powder flux exhibits multiple melting peaks with the deepest at ∼1062 °C, showing a multi-stage melting behavior that is frequently observed in glass materials with multiple components. , As the investigations in this work were focused on the crystallization process, the temperature range for in situ studies was set from RT to 800 °C.…”