Ti is an important active element to join SiO2f/SiO2 composite materials. Therefore, the bonding mechanism of Ti and SiO2 was studied by using first principle calculation. Two kinds of interfaces with different termination and stoichiometric ratio were studied by the results of work of separation (Wsep), electron behavior and interface energy. It is found that in the O-terminated interface, Ti and O atoms form a strong ionic-covalent bonding, resulting in the largest Wsep of 8.99 J/m2. In the Si-terminated interface, Ti and Si atoms form covalent-ionic bonding, and the Wsep is 2.65 J/m2. At the temperature of 1 173 K, when the activity of Si is larger than e−35, the interface of Si-terminated interface is more lower. The Ti-Si compounds are more favored at the interface. When the activity of Si is smaller than e−35, the O-terminated interface is more stable in thermodynamics and the Ti-O compounds are more favored at the interface. After Si in SiO2 in replaced by Ti, Si will diffuse into the solder and react with Ti in the solder to form Ti-Si compounds, so the interface struture is SiO2/Ti-O compound/Ti-Si compound/solder.
XUE Haitao
,
WEI Xin
,
GUO Weibing
,
ZHANG Xiaoming
. First principle calculation of the binding mechanism between Ti and SiO2[J]. Transactions of The China Welding Institution, 2020
, 41(1)
: 67
-71
.
DOI: 10.12073/j.hjxb.20190712001
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