ISSN:
1662-8985
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 sintering of Low Temperature Co-fired Ceramics prepared from alumoborosilicateglass- and Al2O3 powders of similar small particle size was studied by dilatometry, heating microscopy,microstructure analysis, glass- and effective viscosity measurements. The steric effect ofAl3O3 inclusions was studied using a “non-reactive” model composite. With increasing Al3O3 volumefraction ( Φ ≤ 0.45), sintering decelerates and its final stage shifts to higher temperature. Theattainable shrinkage is reduced as Al2O3 particle clusters bearing residual pores become more frequent.The kinetics of sintering could be described formally superposing the weighed contributionsof differentially sized and randomly composed glass-crystal particle clusters and assuming a sinteringrate controlled by the effective matrix viscosity, which increases with Φ and with progressivewetting of Al2O3 particles during densification. The “reactive” model composite shows significantdissolution of Al2O3 into the glass, which has two opposed effects on sintering: reducing Φ and increasingglass viscosity. For the present case ( Φ = 0.25), the latter effect dominates and sintering isretarded by Al2O3 dissolution. Crystallization of wollastonite starts after full densification. Dissolutionof Al2O3 was found to promote the subsequent growth of anorthite
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/01/40/transtech_doi~10.4028%252Fwww.scientific.net%252FAMR.39-40.375.pdf
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