Effect of Carbon nanotubes addition on the foundry physical properties of Silica refractory nanocomposite: PART A

摘要

The foundry physical properties of carbon nanotube(CNT)reinforced silica refractory ceramic nanocomposites have been determined.The pristine CNTs(pCNTs)were acid treated and subsequently dispersed in distilled water to achieve a stable suspension of functionalized CNTs(fCNTs).The as-prepared suspension,natural crystalline powdered quartz(SiO2)and calcium oxide-clay;as binder and sintering aids(SA);stabilizer and mineralizer were mixed thoroughly by ultrasonication/ball milling,dried,cold compacted and densified by pressureless sintering consolidation technique via modified conventional powder processing.The comparable bulk density obtained for the sintered SiOi-x/CNT-SA;x = 0,0.01,1 and 4 wt.% blends is an evidence of a complete densification and good homogenous dispersion of CNTs in the green matrices,thus better thermo-mechanical properties of the nanocomposites.Low linear/diametric expansion(1.37/1.57 ± 0.01%),high bulk density(1.735 ± 0.010 5/cm~3),moderate apparent porosity(41.28 ± 0.41%)and cold crushing strength(177 ± 9 kg/cm~2),and higher thermal shock cycles(7 ± 1 cycles)of 1 wt.% fCNT-silica nanocomposite brick as compared to those of monolithic conventional silica brick signified the possibility of potential application of CNT as an additive in conventional green silica refractory mixture for better foundry physical properties.