Can glass stability parameters infer glass forming ability?

Abstract

Glass-forming ability (GFA) is the easiness to vitrify a liquid on cooling, while glass stability (GS) is the glass resistance against devitrification on heating; but it is questionable if there is any direct relationship between these two parameters. Therefore, to test this possibility, we assess and compare GFA and several GS parameters through quantitative criteria. GFA and GS were calculated for six stoichiometric glass forming oxides that only present surface (heterogeneous) crystallization in laboratory time scales: GeO 2 , Na 2 O AE 2SiO 2 , PbO AE SiO 2 , CaO AE Al 2 O 3 AE 2SiO 2 , CaO AE MgO AE 2SiO 2 and 2MgO AE 2Al 2 O 3 AE 5SiO 2 ; plus Li 2 O AE 2SiO 2 and Li 2 O AE 2B 2 O 3 that, in addition to surface nucleation, also present homogeneous (internal) crystallization. We gauge GFA by the critical cooling rate, q cr , which was calculated from an estimated number of heterogeneous nucleation sites per unit surface, N s , and from experimental crystal growth rates, u(T), assuming a detectable surface crystallized fraction X c = 0.001. We define GS parameters by fourteen different combinations of the following characteristic differential thermal analysis (DTA) or differential scanning calorimetry (DSC) temperatures: the glass transition temperature (T g ), the onset crystallization temperature on heating ðT h x Þ, the peak crystallization temperature on heating ðT h c Þ, and the melting point (T m ). To obtain the experimental GS parameters for each glass we carried out DSC runs using coarse and fine powders, and completed the necessary data with literature values for T m . The results for fine and coarse particles were quite similar. Most of the GS parameters that consist of three characteristic DSC temperatures show excellent correlation with GFA, however, rather poor correlations were observed for parameters that use only two characteristic temperatures. We thus demonstrated that certain, but not all GS parameters can be used to infer GFA.

Thermal properties of phosphate glasses for salt waste immobilization

“…All of the investigated glasses except glass PFS50 evidenced good thermal stability comparable with conventional silicate glasses for which K H value varied from 0.14 to about 1.3 [7][8][9]. The increasing Na 2 SO 4 addition causes decrease of the K H parameter which means lowering the glass stability against crystallization and at the same ability of glass to vitrify on cooling [9].…”

“…The increasing Na 2 SO 4 addition causes decrease of the K H parameter which means lowering the glass stability against crystallization and at the same ability of glass to vitrify on cooling [9].…”

Thermal properties of 60P2O5–20Fe2O3–20Al2O3 glass for salt waste immobilization

“…All of the investigated glasses evidenced a quite good thermal stability comparable with conventional silicate glasses for which K H value varied from 0.14 to about 1.3 [16,[27][28][29][30]. The increasing Na 2 SO 4 addition causes decrease in the K H parameter which means lowering the glass stability against crystallization and at the same ability of glass to vitrify on cooling [30].…”

“…The increasing Na 2 SO 4 addition causes decrease in the K H parameter which means lowering the glass stability against crystallization and at the same ability of glass to vitrify on cooling [30]. The lowest K H value is Enthalpy of crystallization calculated from DSC curves exothermic peak area is growing up rapidly with Na 2 SO 4 content, but above x = 30 mol% is falling down (Fig.…”

Structural, thermal and optical properties of CaBO and CaLiBO glasses doped with Eu3+

“…Thermal characteristics of the glasses were evaluated by three thermal parameters: i) ΔT = T x − T g , being T x the onset of crystallization, implies the glass stability against devitrification; ii) K H ¼ Tc−Tg Tm (Hrüby's parameter) and iii) K w ¼ Tc−Tg Tm (Weinberg's parameter), by considering T c as the maximum of crystallization, are associated to the glass stability against crystallization on heating and can also be correlated to the glass forming ability [16,17]. As larger the K H , or K w parameter, the higher the glass stability on heating [17].…”