TY - JOUR
T1 - Synthesis of Novel Al2O3-Mullite-cBN Composites from a Mixture of Al2O3 with SiO2 Nanolayer Coated cBN by Rotary CVD and Spark Plasma Sintering
AU - Zhang, Xin
AU - Zhang, Jianfeng
AU - Goto, Takashi
AU - Wu, Yuping
N1 - Publisher Copyright:
© 2015 Indian Ceramic Society.
PY - 2015/7/3
Y1 - 2015/7/3
N2 - In the present study, novel Al2O3-mullite-cBN composites were synthesized from a mixture of Al2O3 and SiO2 coated on cBN (cBN/SiO2) by spark plasma sintering. SiO2 nanolayer was coated on cBN powder (cBN/SiO2) by rotary CVD using tetraethyl orthosilicate as a precursor and O2 as a reactive gas. The thickness of SiO2 nanolayer (TSSiO2) increased from 32 to 52 nm with increasing FO2 from 0 to 0.42×10−6 m3.s−1, and then decreased to 25 nm with increasing FO2 to 0.42×10−6 m3.s−1. The cBN/SiO2 powder was mixed with Al2O3 and consolidated by spark plasma sintering at 1473–1873 K for 0.6 ks. A uniform mullite (Al6Si2O13) phase was formed at 1673 K by the reaction of SiO2 nanolayer with Al2O3. At a sintering temperature of 1573 K and TSSiO2=52 nm, the relative density and the hardness of Al2O3-mullite-cBN was 97% and 24.9 GPa, respectively. The obtained hardness was about 3.9 GPa higher than that of monolithic Al2O3, 12.4 GPa higher than that of SiO2-cBN, and 8.9 GPa higher than that of SiAlON-cBN and mullite-cBN composites, suggesting that the as-obtained Al2O3-mullite-cBN composites could be possibly used for cutting and wear resistant applications.
AB - In the present study, novel Al2O3-mullite-cBN composites were synthesized from a mixture of Al2O3 and SiO2 coated on cBN (cBN/SiO2) by spark plasma sintering. SiO2 nanolayer was coated on cBN powder (cBN/SiO2) by rotary CVD using tetraethyl orthosilicate as a precursor and O2 as a reactive gas. The thickness of SiO2 nanolayer (TSSiO2) increased from 32 to 52 nm with increasing FO2 from 0 to 0.42×10−6 m3.s−1, and then decreased to 25 nm with increasing FO2 to 0.42×10−6 m3.s−1. The cBN/SiO2 powder was mixed with Al2O3 and consolidated by spark plasma sintering at 1473–1873 K for 0.6 ks. A uniform mullite (Al6Si2O13) phase was formed at 1673 K by the reaction of SiO2 nanolayer with Al2O3. At a sintering temperature of 1573 K and TSSiO2=52 nm, the relative density and the hardness of Al2O3-mullite-cBN was 97% and 24.9 GPa, respectively. The obtained hardness was about 3.9 GPa higher than that of monolithic Al2O3, 12.4 GPa higher than that of SiO2-cBN, and 8.9 GPa higher than that of SiAlON-cBN and mullite-cBN composites, suggesting that the as-obtained Al2O3-mullite-cBN composites could be possibly used for cutting and wear resistant applications.
KW - Cubic boron nitride (cBN)
KW - Densification
KW - Rotary CVD
KW - SiO nanolayer
KW - Spark plasma sintering
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U2 - 10.1080/0371750X.2015.1051627
DO - 10.1080/0371750X.2015.1051627
M3 - Article
AN - SCOPUS:84945462238
VL - 74
SP - 148
EP - 151
JO - Transactions of the Indian Ceramic Society
JF - Transactions of the Indian Ceramic Society
SN - 0371-750X
IS - 3
ER -