Microstructure Evolution of TiB2/7075 Composites in Semi-Solid State near Liquids within Holding Time


Article Preview

Novel reactive technique has been employed in synthesis of 7075 Al matrix composites, and effect of TiB2 particles on sedimentation and microstructure of 7075 Al Alloy in near liquidus was investigated. Researchers have shown that 4.5%TiB2/7075 composites had the smallest grains and the minimum liquidus and solidus temperatures in 7075 Al matrix composites. 4.5%TiB2/7075 composites holding for 21 hours appeared stratification phenomenon, the globular grains were 61μm and 214μm, 250μm and 283μm with the increase of holding time respectively. The microstructures evolution of TiB2 /7075 composites holding for different time at 635°C was a two-stage mechanism that the globular grains was formed firstly and secondly sedimentation and layering were began after a period of time of Ostwald ripening. The globular grain continued to increase during the settling process.



Solid State Phenomena (Volume 285)

Edited by:

Qiang Zhu, Ahmed Rassili, Stephen P. Midson and Xiao Gang Hu




G. S. Gan et al., "Microstructure Evolution of TiB2/7075 Composites in Semi-Solid State near Liquids within Holding Time", Solid State Phenomena, Vol. 285, pp. 127-132, 2019

Online since:

January 2019




* - Corresponding Author

[1] D.B. Spencer, R.Mehrabian, M.C. Flemings, Rheological behavior of Sn-15 pct Pb in the crystallization range, Metall Trans B. 3(1972)1925–32.

DOI: https://doi.org/10.1007/bf02642580

[2] X.Wang, Z.Liu, W.Dai, Q.Han, On the understanding of aluminum grain refinement by Al-5Ti-B type master alloys, Metall. Mater. Trans. B. 46(2015)1620–1625.

DOI: https://doi.org/10.1007/s11663-014-0252-3

[3] E.Z. Wang, X.F. Liu, Grain reinement limit of commercial pure al inoculated by Al-Ti-C (B) master alloys, China Foundry. 12(2015)99–103.

[4] Z. Chen, T. Wang, Y. Zheng, Y. Zhao, H. Kang, L.Gao, Development of TiB2 reinforced Aluminum foundry alloy based in situ composites: Part I: An improved halide salt route to fabricate Al-5 wt.% TiB2 master composite, Mater. Sci. Eng. A .605(2014)301–309.

DOI: https://doi.org/10.1016/j.msea.2014.02.088

[5] Q. Gao, B. Yang, H.Mei, H.C.Wu, Microstructure and wear resistance of semisolid TiB2/7050 composites produced by serpentine tube pouring technique, Mater. Manuf. Proces. 31(2016)1029–1036.

DOI: https://doi.org/10.1080/10426914.2015.1037917

[6] Z.Fan, Y.Wang, Y. Zhang, T.Qin, X.R. Zhou, G.E. Thompson, Pennycook, T.; Hashimoto, T. Grain refining mechanism in the Al/Al–Ti–B system, Acta. Mater.84(2015)292–304.

DOI: https://doi.org/10.1016/j.actamat.2014.10.055

[7] G.S. Gan, B.Yang, H.C.Wu, C.H.Du,The Effect of TiB2 Particles on the Microstructure of Semi-Solid 7075 Alloy Slurry,Mater. Trans. 53(2012)1178-1183.

DOI: https://doi.org/10.2320/matertrans.m2011328

[8] G.S. Gan, B.Yang, B.Zhang, JX.iang, Y.L. Shi, Y.P.Wu, Refining Mechanism of 7075 Al Alloy by In-Situ TiB2 Particles, Materials. 10(2017)132.

DOI: https://doi.org/10.3390/ma10020132

[9] G.S. Gan, B.Yang, Microstructure evolution of TiB2 particle-reinforced 7075 Al alloy slurry in semisolid state with different holding time, Rare Metals .5(2016)1-5.

DOI: https://doi.org/10.1007/s12598-015-0639-6

[10] G.S. Gan, H.S. Wang, G.Q. Meng, B.Yang, Effect of TiB2 Particles on Microstructure of 7075 Al Alloy in Semi-Solid State Near Liquidus, Mater. Trans. 56(2015)1787-1792.

DOI: https://doi.org/10.2320/matertrans.m2014447

[11] G.S. Gan, B.Yang, Q.Gao, Y.P. Wu, M.B. Yang, Microstructure and Viscosity of Particles Reinforced 7075 Al Matrix Composites. Mater. Trans. 57(2016)1296-1299.

DOI: https://doi.org/10.2320/matertrans.m2016085

[12] G.S. Gan, B. Yang, Solidification microstructures of 7075 aluminum alloy with in-situ TiB2 particles, Rare Metals. 38(2014)954-960. (In Chinese).

[13] J.Wang, Q.X. Guo, N.Mitsuhiro, M.Nishio, H.Ogawa, D.Shu,K. Li,The apparent viscosity of fine particle reinforced composite melt, J. Mater. Process. Technol. 136(2003)60–63.

DOI: https://doi.org/10.1016/s0924-0136(02)00919-6

[14] L.N.Yu,H. M.Wang, X.F. Liu, J.T. Liu, X.F. Bian, Sudden change of aluminum melt viscosity aroused by a little amount of TiC or TiB2 particles,Foundry. 28(2007)796-799. (In Chinese).

[15] L.N. Yu and X.F. Liu, The Relationship Between Viscosity and Refinement Efficiency of Pure Aluminum by AI-Ti-B Refiner, Journal of Alloys and Compounds, J Alloy Compd. 425 (2006)245-250.

DOI: https://doi.org/10.1016/j.jallcom.2006.08.257

[16] L.N. Yu and X.F. Liu, Ti transition zone on the interface between TiC and Aluminum melt and its influence on melt viscosity, J. Mater. Process. Technol. 182(2007)519-524.

DOI: https://doi.org/10.1016/j.jmatprotec.2006.09.011

[17] S. Lakshmi, L. Lu, M. Gupta, In situ preparation of TiB2, reinforced al based composites, J. Mater. Process. Technol. 73(1998)160–166.

DOI: https://doi.org/10.1016/s0924-0136(97)00225-2

[18] M.Wang, J.J. Gao, S. X.Chen, Study on the interfacial microstructures of in-situ TiB2/Al composites, Foundry Technology.28(2007)796-799.