Abstract
Abstract MgAl 2 O 4 nanoparticles (NPs) were prepared by sol–gel method using aluminium nitrate, magnesium nitrate and citric acid as starting materials, phenolic formaldehyde resin and carbon black as additives. Growth of MgAl 2 O 4 NPs in different heat treatment conditions (temperature, atmosphere, carbon additives and in Al 2 O 3 -C system) was investigated. MgAl 2 O 4 NPs were formed at 600 °C in air atmosphere with serious agglomeration of nanoparticles having diameter of approximate 30 nm. The size of MgAl 2 O 4 NPs increased greatly from 40 to 50 nm to several hundreds of nanometres as the temperature was raised from 800 °C to 1400 °C. Partial sintering of NPs was observed upon heating at temperatures higher than 1200 °C in air. In reducing atmosphere, the size of MgAl 2 O 4 NPs (about 30–50 nm) changed slightly with increasing temperature. This was attributed to the dispersion of carbon inclusions in the MgAl 2 O 4 grain boundaries, inducing a steric hindrance effect and inhibiting the growth of particles. MgAl 2 O 4 NPs (30–50 nm) in the Al 2 O 3 -C system were in-situ formed at high temperatures with the use of dried precursor gels. MgAl 2 O 4 NPs can contribute to improving the thermal shock resistance of Al 2 O 3 -C materials.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
