Investigation of R-Curve Behavior in Glass Ceramic Materials.

Local and conventional raw materials?massive basalt from the Vrelo locality on Kopaonik mountain?have been used as starting materials to test their suitability for the production of glass-ceramics. Crystallization phenomena of glasses of the fused basalt rocks were studied by X-ray phase analysis optical microscopy and other techniques. Various heat treatments were used and their influences, on controlling the microstructures and properties of the products were studied with the aim of developing high strength glass-ceramic materials. Diopside CaMg(SiO3)2 and hypersthene ((Mg,Fe)SiO3) were identifies as the crystalline phases. The final products contained considerable amounts of a glassy phase. The crystalline size was in range of 8?480 ?m with plate or needle shape. Microhardness, crashing strength and wears resistence of the glass-ceramics ranged from 6.5?7.5, from 2000?6300 kg/cm2 and from 0.1?0.2 g/cm, respectively.

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Solid Solutions Formation Mechanism in Cordierite-Mullite Glass Materials During Ceramization

Chemistry & Chemical Technology ◽

10.23939/chcht14.04.583 ◽

2020 ◽

Vol 14 (4) ◽

pp. 583-589

Author(s):

Оksana Savvova ◽

◽

Hennadiy Voronov ◽

Оlena Babich ◽

Oleksii Fesenko ◽

...

Keyword(s):

Heat Treatment ◽

Formation Mechanism ◽

Glass Ceramic ◽

High Strength ◽

Ceramic Materials ◽

Ceramic Coatings ◽

Resource Saving ◽

Aluminosilicate Glasses ◽

Glass Ceramic Materials ◽

Fine Crystalline Structure

Relevance of the development of high-strength glass-ceramic coatings obtained by resource-saving technology for protective elements has been established. Structure formation mechanism in magnesium aluminosilicate glasses during heat treatment has been analyzed. Selection of the system was substantiated, model glasses and glass-ceramic materials on its base have been developed. Patterns of structure regularity and formation of the phase composition of glass-ceramic materials during their ceramization have been investigated. It was established that the presence of crystalline phase of mullite after melting leads to formation of the primary crystals and allows the formation of the fine crystalline structure under conditions of the low-temperature heat treatment at the nucleation stage. Developed high-strength glass ceramic materials can be used as a base in creating protective elements for special-purpose vehicles by energy-saving technology.

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Utilization of discarded foundry sand (DFS) and inorganic waste from cellulose and paper industry for the manufacture of glass-ceramic materials

Cerâmica ◽

10.1590/0366-69132020663802899 ◽

2020 ◽

Vol 66 (380) ◽

pp. 413-420

Author(s):

L. M. S. e Silva ◽

R. S. Magalhães ◽

W. C. Macedo ◽

G. T. A. Santos ◽

A. E. S. Albas ◽

...

Keyword(s):

Glass Ceramic ◽

Raw Materials ◽

Paper Industry ◽

Glass Ceramics ◽

Ceramic Materials ◽

Gravimetric Analysis ◽

Scanning Calorimetry ◽

Foundry Sand ◽

X Ray ◽

Glass Ceramic Materials

Abstract Recycling has been pointed out as an alternative to the disposal of waste materials in industrial landfills. In the present study, the transformation of residues (discarded foundry sand - DFS, grits, and lime mud) in glass-ceramic materials is shown. The glasses were obtained by the melting/cooling method. The precursor materials, glasses, and glass-ceramics were characterized by X-ray diffraction (XRD), X-ray fluorescence (XRF), and differential scanning calorimetry/thermal gravimetric analysis (DSC/TGA). The glassy materials were milled, pelleted, and thermally treated at the crystallization temperatures given by DSC data to obtain the glass-ceramics (885, 961, and 1090 ºC). The main formed phases were cristobalite, α-wollastonite (parawollastonite), and β-wollastonite (pseudowollastonite). The glass-ceramics showed very low water absorption and apparent porosity (0.26 to 0.88 wt% and 0.66 to 1.77 vol%, respectively). The results confirmed that the studied residues can be used as raw materials for the manufacture of vitreous and glass-ceramic materials.

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