TY - JOUR
T1 - Improved densification and mechanical properties of spark plasma sintered carbon nanotube reinforced alumina ceramics
AU - Sikder, Prabaha
AU - Sarkar, Soumya
AU - Biswas, Kriti Gaurab
AU - Das, Santanu
AU - Basu, Sumantra
AU - Das, Probal Kr.
PY - 2016/2/15
Y1 - 2016/2/15
N2 - Dense magnesium oxide (MgO) doped multiwalled carbon nanotube (MWCNT) reinforced alumina (Al2O3) nanocomposites were fabricated using spark plasma sintering (SPS). Sintered nanocomposites possessed refined microstructure due to the presence of uniformly dispersed CNTs and ability of MgO to increase densification rate before onset of abnormal grain growth. Williamson-Hall analyses of XRD patterns indicated that matrix crystallite size (LC) and lattice micro-strain (εC) of the nanocomposites decreased by ∼40% and >30%, respectively, than those of pure Al2O3 (LC 75 nm, εC = 1.54 × 10-3). Present investigation also depicted the suitability of CNT addition in Al2O3 towards achieving higher density of nanocomposites using low temperature (1300 °C) SPS. Addition of CNT (especially, at 0.6 vol.%) in highly electrically insulating matrix established an electrical percolating network that helped in local heating of matrix particles during SPS and led to higher densification. The highest changes in indentation fracture toughness at 1 kgf and wear rate at 20N normal load were obtained at only 0.6 vol.% MWCNT loading which were >22% higher and 35% lower, respectively, compared to pure Al2O3.
AB - Dense magnesium oxide (MgO) doped multiwalled carbon nanotube (MWCNT) reinforced alumina (Al2O3) nanocomposites were fabricated using spark plasma sintering (SPS). Sintered nanocomposites possessed refined microstructure due to the presence of uniformly dispersed CNTs and ability of MgO to increase densification rate before onset of abnormal grain growth. Williamson-Hall analyses of XRD patterns indicated that matrix crystallite size (LC) and lattice micro-strain (εC) of the nanocomposites decreased by ∼40% and >30%, respectively, than those of pure Al2O3 (LC 75 nm, εC = 1.54 × 10-3). Present investigation also depicted the suitability of CNT addition in Al2O3 towards achieving higher density of nanocomposites using low temperature (1300 °C) SPS. Addition of CNT (especially, at 0.6 vol.%) in highly electrically insulating matrix established an electrical percolating network that helped in local heating of matrix particles during SPS and led to higher densification. The highest changes in indentation fracture toughness at 1 kgf and wear rate at 20N normal load were obtained at only 0.6 vol.% MWCNT loading which were >22% higher and 35% lower, respectively, compared to pure Al2O3.
KW - Composite materials
KW - Mechanical properties
KW - Powder diffraction
KW - Tribology
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U2 - 10.1016/j.matchemphys.2015.12.024
DO - 10.1016/j.matchemphys.2015.12.024
M3 - Article
SN - 0254-0584
VL - 170
SP - 99
EP - 107
JO - Materials Chemistry and Physics
JF - Materials Chemistry and Physics
ER -