Zhu Shigen, Shi Tianyu, Cheng Kai. Effects of CeO2 and VC on the Structure and Properties of Graphene-contained WC-Al2O3 Composites. [J]. Special Casting & Nonferrous Alloys 41(10):1197-1203(2021)
DOI:
Zhu Shigen, Shi Tianyu, Cheng Kai. Effects of CeO2 and VC on the Structure and Properties of Graphene-contained WC-Al2O3 Composites. [J]. Special Casting & Nonferrous Alloys 41(10):1197-1203(2021) DOI: 10.15980/j.tzzz.2021.10.003.
Effects of CeO2 and VC on the Structure and Properties of Graphene-contained WC-Al2O3 Composites
The hard composite preparation method based on hot pressing and sintering was adopted
and rare earth oxide CeO
2
powder and the grain growth inhibitor VC powder were induced into the graphene-contained WC-Al
2
O
3
composite powders to prepare a new type of composites. The phase composition
microscopic morphology
densification process and mechanical properties were investigated. The results indicate that the addition of CeO
2
(0.1%) and VC(0.3%) results in the increase of the composite density from 95.536% to 98.059% and 97.256%
respectively. The brittle phase W
2
C in the sintered specimen is reduced with mechanical property improvement. CeO
2
(0.1%) has a great effect on the fracture toughness
which is increased by 26.25%. Grains in composites are fine
round and smooth without abnormal growth
VC(0.3%) has a significant effect on the hardness. The Vickers hardness is increased by 21.06% compared to the original one with the smallest grain size and incomplete fusion
where a small number of pores exist between some grains. Synchronous addition of CeO
2
(0.1%) and VC(0.3%) leads to the dissolution of large amounts of Ce and V into the crystals
which promotes the vacancy generation
accelarate the transfer of substance and the growth of crystal grains
and reduces refinement effect. Meanwhile
more gas generated by the reaction is harmful to material densification.