Thermodynamic Analysis of Ti₃O₅Nanoparticles Formed in Melt and Their Effects on Ferritic Steel Microstructure

Yanlin Wang; Meng Zhou; Xiaolu Pang; Xiaohua Chen; Zidong Wang; Alex A Volinsky; Hao Tang

doi:10.3390/ma11081343

Thermodynamic Analysis of Ti₃O₅Nanoparticles Formed in Melt and Their Effects on Ferritic Steel Microstructure

Materials (Basel). 2018 Aug 2;11(8):1343. doi: 10.3390/ma11081343.

Authors

Yanlin Wang^{1

2}, Meng Zhou³, Xiaolu Pang⁴, Xiaohua Chen⁵, Zidong Wang⁶, Alex A Volinsky⁷, Hao Tang⁸

Affiliations

¹ School of Mechanical Engineering, Dongguan University of Technology, Dongguan 523808, China. Wangyanlin921@aliyun.com.
² School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China. Wangyanlin921@aliyun.com.
³ School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China. zhoumeng0902@126.com.
⁴ School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China. pangxl@mater.ustb.edu.cn.
⁵ State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083, China. chenxh@skl.ustb.edu.cn.
⁶ School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China. wangzd@mater.ustb.edu.cn.
⁷ Department of Mechanical Engineering, University of South Florida, Tampa, FL 33620, USA. volinsky@usf.edu.
⁸ School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China. mwtwfx@163.com.

Abstract

Based on the Wagner's formalism combined with mass conservation, a thermodynamic analysis method has been developed previously. This method enables the calculation of the equilibrium matrix composition, precipitate composition and precipitate total molar fraction for Ti_xO_y(s) in molten metal, which can be determined at any appropriate temperature. In this present study, the Ti₃O₅ phase precipitation and the quantitative relationship between the addition of Ti, O and Ti₃O₅ in the molten steel were studied using the thermodynamic model. Using the combined multipoint dispersion supply method, electromagnetic stirring and well-dispersed 5-nm Ti₃O₅ nanoparticles were fabricated in the ferrite matrix of the as-cast high-strength steel with 0.05 wt % Ti-0.002 wt % O. The as-cast microstructure was improved by the homogeneously dispersed Ti₃O₅ nanoparticles through heterogeneous nucleation and grain refinement.

Keywords: ferritic steel; metallurgy; microstructure; nanoparticles; thermodynamics analysis.