Formation mechanism of TiB2 nanoparticles and development of TiB2p/6201 nanocomposites as a neoteric conducting material
Zhao, Kai 1Kanga, Huijun 1Guoa, Enyu 1Lic, Jiehua 2Liu, Lei 3Chena, Zongning 1Wanga, Tongmin 1Liu, Mengmeng1
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作者信息
1. Dalian Univ Technol
2. Montanunivers Leoben
3. Ningbo Inst Dalian Univ Technol
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Abstract
TiB2 nanoparticles were fabricated by the melt reaction between Al-10Ti and Al-3B master alloys. The reaction mechanism is ascribed to the decomposition of Al3Ti to release free Ti atoms, which diffuse across the AlB2/Al interface and substitute the Al atoms to form TiB2. This substitution produces a layer of pseudoTiB2 on the prism planes {10-10}AlB2 firstly, which has the same lattice structure and the similar values of the lattice parameter as AlB2. It follows the fact that the nucleation occurs at the prism planes {10-10}. Subsequently, the epitaxial transformation of TiB2 particles is initiated inward the pseudo-TiB2, which becomes detached from the substrate owing to the crystallographic mismatch between the two, thus forming the TiB2 nanoparticles. The exposed AlB2 prism surfaces continue to react with Ti atoms until they are totally consumed. Increasing the reaction temperature, prolonging the holding time could improve the extent of reaction, thus increasing the electrical conductivity and reducing the elastic modulus. Especially, the effects of ultrasonic vibration treatment (UVT) on the reaction process were explored. Cavitation and acoustic flow generated by UVT showed a magnificent potential for promoting the reaction in melts. Thanks to the interface reaction, nano-TiB2 particles can be generated. The nano-TiB2p/6201 composites produced by this method recorded significant improvement in the tensile properties.(c) 2022 Elsevier B.V.All rights reserved.
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Elsevier