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Effect of nano CuO addition on the tribo‐mechanical behavior of alumina ceramics in non‐conformal contact
Author(s) -
Haldar Partha,
Bhattacharya Tapas Kumar,
Modak Nipu
Publication year - 2020
Publication title -
international journal of applied ceramic technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.4
H-Index - 57
eISSN - 1744-7402
pISSN - 1546-542X
DOI - 10.1111/ijac.13620
Subject(s) - materials science , sintering , ceramic , composite material , fracture toughness , ultimate tensile strength , nano , grain size , grain boundary , phase (matter) , microstructure , metallurgy , chemistry , organic chemistry
Sintering of alumina from 1500°C to 1650°C and tribo‐mechanical properties at room temperature had been investigated using nano CuO as a sintering aid. Bulk density gradually increases with sintering temperature from 1500°C to 1600°C and is optimized at 1600°C, beyond this, bulk density does not significantly increase at 1650°C. The addition of 2 wt% CuO showed the best result on densification. Densification of about 97.74% was attained at 1600°C with the incorporation of 2 wt% CuO. Nano CuO at grain boundaries forms CuAl 2 O 4 liquid which modifies the morphology of the grain and improves mechanical properties. The formation of self‐lubricating tribo‐film on the wear track results in a low coefficient of friction <0.2 and reduces specific wear rate. 4 wt% CuO addition increases contact tensile stress ( σ max ) by 51.2% and high Hertzian contact pressure ( P max ≈1.51 GPa) causes plastic deformation of wear track. The re‐solidified strengthening bond phase on the wear track simultaneously increases in friction coefficient and wear resistance with CuO addition. The optimizing effect of CuO addition shows that 2 wt% significantly decreases wear rate, and increases hardness and fracture toughness.