ISSN:
1013-9826
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
The phase-separation and the crystallization of SiO2-MgO-Al2O3-K2O-Fe2O3-F glass wereinvestigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and electron probe ofmicroanalyzers (EPMA). The results reveal that the varieties and the morphology of crystalline phasesformed depend sensitively on the thermal treatment schedules. During the isothermal treatments, thecrystalline phases of mica, mica and iron oxide (FeFeO4), and FeFeO4 as major crystals are precipitated inthe glass samples heat-treated at 900, 1000 and 1050°C respectively. However, the two-step heattreatment beginning at 900°C for 1h and subsequently followed at 1050°C for 1h leads to the precipitationof mica crystal and no any signs of FeFeO4 crystalline phase is observed. Also the morphology of sampleis different from that of the isothermally treated glass at 1050°C, but is similar from that of sample at900°C. A “worm”-shaped phase-separation is observed in the sample heated at 800°C for 0.5h, whichexhibits different morphology from that of droplet- or globule-shape conventionally discerned. EPMAresults show that the incorporation of Fe2O3 accelerates accumulation of fluorine element, promoting thephase-separation and the crystallization of the present glass
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/01/53/transtech_doi~10.4028%252Fwww.scientific.net%252FKEM.336-338.1829.pdf
Permalink