Diffusion coefficient of Ti⁴⁺ in calcium ferrite/calcium titanate diffusion couple

Abstract

This study investigated the interdiffusion of calcium ferrite/calcium titanate system in the time range of 0–120 min by the diffusion couple method in a CO/N₂ reducing atmosphere at 700°C. The results show that after the diffusion reaction occurred, no longitudinal agglomerations were present on the substrate surface on the calcium titanate side. When the diffusion time was increased to 105 min, a net vacancy flow from calcium titanate to calcium ferrite might have occurred, causing the surface of the calcium ferrite substrate to collapse. The thickness of the diffusion layer of the calcium ferrite/calcium titanate system was about 17–48 µm, which conforms to the parabolic law of diffusion. The diffusion coefficient and the Ti⁴⁺ concentration in the calcium ferrite/calcium titanate system are related. This shows an increase in the diffusion coefficient with the increase of Ti⁴⁺ concentration, and the diffusion coefficient value was in the range of 10⁻¹²–10⁻¹¹ cm²·s⁻¹.

Keywords

vanadium-titanium sinter / diffusion couple / calcium ferrite / calcium titanate / diffusion coefficient

References

[1] Q.X Wu, J.P. Wang, D. Che, and Y. Gu, Situation analysis and sustainable development suggestions of vanadium resources in china, Resour. Ind., 2016, No. 3, p. 29.

[2] Li S. Study on China’s Iron Ore Import and Countermeasures, 2010, Dalian, Dongbei University of Finance and Economics [Dissertation]

[3] D.B. Zhang, H.M. Wan, and J. Zheng, Analysis on global iron ore resources and China’s iron ore supply and demand, China Metall., 2004, No. 6, p. 26.

[4] F.K. Meng, Current status and prospects of utilization of titanium resources in Chengde, Titanium Ind.Prog., 2001, No. 5, p. 11.

[5] J.M. Ma and C.X. Cheng, New types of development and utilization of iron ore resources in China—Ultra-lean vanadium-titanium magnetite of Chengde, Land Resour. Inf., 2006, No. 11, p. 53.

[6] Ju JH, Huang XX, Xue YZ, Song M. Thoughts of mineral resources conservation and comprehensive utilization in China in new era. ChinaMin. Mag., 2018, 27(1): 1.

[7] J.S. Zhu, Beneficiation and comprehensive utilization of vanadium-titanium magnetite, Met. Mine, 2000, No. 1, p. 1.

[8] W.Z. Fu, Basic analysis of the characteristics and comprehensive utilization of the vanadium-titanium magnetite resources in Panxi, Multipurpose Util. Miner. Resour., 1996, No. 1, p. 27.

[9] Xu MX. Influences of metallurgical properties of sinter on its quality and major operation indexes of blast furnace. Sintering Pelletizing, 2014, 39(3): 1.

[10] Chen Y. The Investigation of Phase Constitution and Reaction Between Titanium Dioxide and Calcium Ferrite, 2017, Chongqing, Chongqing University [Dissertation]

[11] Cheng GJ, Xue XX, Jiang T, Duan PN. Effect of TiO₂ on the crushing strength and smelting mechanism of high-chromium vanadium-titanium magnetite pellets. Metall. Mater. Trans. B, 2016, 47(3): 1713.

[12] He MG. Effect of w(TiO₂) on sintering properties of high titanium vanadium-titanium magnetite. Iron Steel, 2016, 51(5): 9.

[13] Budzik R. The balance of titanium and vanadium in the blast furnace with the use of sinter containing a titanium-vanadium-magnetite concentrate. Metalurgija, 2007, 46(2): 145.

[14] Ding CY, Lv XW, Chen Y, Li G, He WC, Lv XM. Reaction sequence and formation kinetics of perovskite by calcium ferrite-titania reaction. J. Alloys Compd., 2019, 789, 537.

[15] H.M. Yang and G.Z. Qiu, Mechanism of TiO₂ affecting sinter RDI, Multipurpose Utiliz. Minser. Resour., 1998, No. 1, p. 12.

[16] Han XL, Wang HF, Liu LN, Yao MY, Wang YH. Influence of basicity on microstructure of vanadium-titanium magnetite sinter. Iron Steel Vanadium Titanium, 2009, 30(3): 56.

[17] Loo CE, Bdstow NJ. Study on low-temperature reduction degradation mechanism of sinter. Sintering Pelletizing, 1995, 20(4): 23.

[18] Ren ZS, Hu XJ, Li SY, Xue XX, Chou KC. Interdiffusion in the Fe₂O₃−TiO₂ system. Int. J. Miner. Metall. Mater., 2013, 20(3): 273.

[19] Ren ZS, Hu XJ, Xue XX, Chou KC. Solid state reaction studies in Fe₃O₄−TiO₂ system by diffusion couple method. J. Alloys Compd., 2013, 580, 182.

[20] Zhao JC. A combinatorial approach for structural materials. Adv. Eng. Mater., 2001, 3(3): 143.

[21] Wu D, Zhang LG, Liu LB, Bai WM, Zeng LJ. Effect of Fe content on microstructures and properties of Ti6Al4V alloy with combinatorial approach. Trans. Nonferrous Met. Soc. China, 2018, 28(9): 1714.

[22] Z.P. Jin, The application of ternary diffusion couple technique to study phase diagram, J. Cent. South Univ. Sci. Technol., 1984, No. 1, p. 27.

[23] Jin ZP. Application of phase diagram in composite materials and surface treatment. Nat. Mag., 1986, 9(5): 340.

[24] Kodentsov AA, Bastin GF, van Loo FJJ. The diffusion couple technique in phase diagram determination. J. Alloys Compd., 2001, 320(2): 207.

[25] Georgiev JS, Anestiev LA. Influence of the surface processes on the hydrogen permeation through ferritic steel and amorphous Fe₄₀Ni₄₀Mo₄B₁₆ alloy specimens. J. Nucl. Mater., 1997, 249(2–3): 133.

[26] Z.H. Xu, R.D Mu, X.Q. Cao, and L.M. He, Study of the inter-diffusion behavior between NiCrAlYSi coating and Ni-based superalloy substrate, J. Mater. Eng., 2009, No. 2, p. 67.

[27] Greskovich C, Stubican VS. Interdiffusion studies in the system MgO−Cr₂O₃. J. Phys. Chem. Solids, 1969, 30(4): 909.

[28] Zhang P, Debroy T, Seetharaman S. Interdiffusion in the MgO−Al₂O₃ spinel with or without some dopants. Metall. Mater. Trans. A, 1996, 27(8): 2105.

[29] Sequeira CAC, Amaral L. Role of kirkendall effect in diffusion processes in solids. Trans. Nonferrous Met. Soc. China, 2014, 24(1): 1.

[30] Wen YN. Study on the Formation of Metal Hollows and the Mechanism of Atomic Migration, 2011, Xi’an, Shaanxi Normal University [Dissertation]

[31] Sung YM, Kwak WC, Kim S. Kinetics of PbTiO₃ perovskite phase formation via an interfacial reaction. J. Mater. Res., 2002, 17(2): 407.

[32] Zheng JC, Hu XJ, Ren ZS, Xue XX, Chou KC. Solid-state reaction studies in Al₂O₃−TiO₂ system by diffusion couple method. ISIJ Int., 2017, 57(10): 1762.

[33] Burns WK, Klein PH, West EJ, Plew LE. Ti diffusion in Ti: LiNbO₃ planar and channel optical waveguides. J. Appl. Phys., 1979, 50(10): 6175.