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:
SiAlON family matrix materials have been fabricated from nonmetallic mine. The process ofCarbothermal Reduction and Nitridation (CRN) is selected on the basis of raw rocks containing variousSi/Al ratios. Thermodynamic analysis of Si-Al-O-N system at different sintering temperatures indicatesonce the temperature is above 1673 K, a series of chemical reactions occur in sequence, SiO2, SiO,Si2N2O, SiO2+Al2O3, mullite, X-SiAlON, O′-SiAlON, β-SiAlON, SiAlON- polytypiods and Si3N4+AlN.Moreover, most of the reactions are exothermal and are promoted by further heating. The adding or in-situformed SiC can reduce mullite and Al2O3 to produce O′- or β-SiAlON, and its reaction is surprisinglyendothermic and is inhibited when further heated. Also, atmosphere is essential to affect the sinteringprocess. Either raising N2 partial pressures or reducing CO partial pressures can accelerate CRN progress.Correspondingly, phase content and microstructure of the product converted from nonmetallic ore are indetail investigated via X-ray diffraction (XRD) and scanning electron microscopy (SEM)
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/01/56/transtech_doi~10.4028%252Fwww.scientific.net%252FKEM.368-372.1564.pdf
Permalink