Microstructure and mechanical properties of MgOC refractories containing graphite oxide nanosheets (GONs)

Significant improvement of refractoriness of Al2O3–C castables containing calcium aluminate nano-coatings on graphite

“…Depending on the partial pressure of carbon monoxide, oxygen and nitrogen, the silicon oxide nitride had also been developed; it too helped in forming a highly compact composite matrix of C+ castable which contributed to superior mechanical properties. Formation of carbide and nitride phases in Al 2 O 3 ͲC and MgOͲC refractories containing carbon nanotubes and graphite oxide nanosheets can render a positive influence on the thermomechanical properties [8,12]. We suggest that similar coatings of moissanite [PDF: 00Ͳ039Ͳ1196] and silicon oxynitride [PDF: 01Ͳ079Ͳ1539] phases (Fig.…”

Effect of the reactivity and porous structure of expanded graphite (EG) on microstructure and properties of Al2O3–C refractories

“…The above possible reactions involved in this system were shown as follows: It is worth noting that the EG may affect the partial pressure of gaseous phases in specimens, which may be ascribed to the high reactivity of the EG. The carbon source with high reactivity might decrease the partial pressure of oxygen [27,45] and increase the partial pressure of nitrogen partial pressure, which would stimulate the nitridation reaction to form more AlN phase and carbonization reaction to form more Al 4 C 3 phase in the matrix at 1000°C [26,46]. Similarly, the addition of EG might decrease the partial pressure of oxygen and increase the partial pressure of Si (g), which would accelerated the formation of much more long SiC whiskers at 1200°C and 1400°C [44].…”

“…Recently, graphene or graphene oxide nanosheets (GONs) was used to improve the performance of ceramic materials due to their unique thermal, mechanical and electrochemical properties [20][21][22][23][24]. In our previous work, the addition of GONs into Al 2 O 3 -C or MgO-C refractories led to the larger force and displacement, which were attributed to the strengthening effects and the in-situ formed whiskers [25,26]. However, as for carbon nanotubes, graphene or GONs, the expensive price and complicated preparation technology restricted their large scale application.…”

Fabrication and properties of MgO–C refractories improved with expanded graphite

“…However, what is amazing is the substantial increase in HMOR for sample X8, at 89.6 kg cm À 2 . Such a significant increase in hot strength has rarely been reported for systems with any form of reactive carbon as replacement for graphite [8][9][10][11][12].…”

“…The use of nanocarbon has shown significant improvement of several properties of low graphite containing MgO-C refractories [10]. Recently, another type of nanostructured carbon, graphene oxide nanosheets (GON), was used as partial replacement for graphite in MgO-C refractories [11]. Some studies have also reported the use of expanded graphite in MgO-C refractories, although the property enhancements have been moderate [12].…”