Effects of Boron and Zirconium on the Microstructure and High-Temperature Strength of Cast Fe3Al-Based Alloys

Document Type: Original Article

Authors

School of Metallurgy and Materials Engineering, Iran University of Science and Technology, Tehran, Iran.

Abstract

In this study, the effects of boron (B) and zirconium (Zr) on the microstructure and high-temperature strength of Fe3Al-based alloys were investigated. Alloying was performed in a vacuum induction melting furnace (VIM) and, consequently, the melt then was poured into a cast iron mold. Microstructural investigation was conducted using optical and electron microscopy, X-ray diffraction, and differential thermal analysis. Addition of B and Zr to the alloys resulted in the formation of boride precipitates and Laves phases. Dendritic microstructures were found in as-cast alloys because of segregation of alloying elements into the interdendritic regions. To evaluate the high-temperature mechanical properties of the alloys, hot pressure test was performed. The results showed that, Zr exhibited the most pronounced effect on the high-temperature strength because of the formation of Laves phases. Boride phases tend to coarsen when increasing the temperature to 650°C, and they have no effect on the high-temperature strength of the alloy. In the temperature range of 450°C–550°C, an anomaly in the temperature-dependence of the yield strength was observed.

Keywords


[1] D.G. Morris, Intermetallics, 6(1998), 753.

[2] N.S. Stoloff, C.T. Liu, Intermetallics, 2(1994), 75.

[3] N.S. Stoloff, Mater. Sci. Eng. A, 258(1998), 1.

[4] G. Sauthoff: Intermetallics, VCH Verlagsgesellschaft, Weinheim, (1995), 65.

[5] W.C. Luu, J.K. Wu, Mater. Chem. Phys., 70(2001), 236.

[6] K.V. edula: Intermetallic compounds, Vol. 2, John Wiley & Sons Ltd., Chichester, (1994), 199.

[7] D.D. Risanti, G. Sauthoff, Intermetallics, 19(2011), 1727.

[8] D.G. Morris, M.A. Muñoz-Morris, Mater. Sci. Eng. A, 462(2007), 45.

[9] M. Palm, Intermetallics, 13(2005), 1286.

[10] R. Krein, A. Schneider, G. Sauthoff and G. Frommeyer, Intermetallics, 15(2007), 1172.

[11] P. Kratochvíl, P. Kejzlarb, R. Krála and V. Vodicková,  Intermetallics, 20(2012), 39.

[12] P. Kratochvíl, F. Dobeš, J. Pešička, P.Málek, J. Buršík, V. Vodičková and P. Hanus, Mater. Sci. Eng. A, 548(2012), 175.

[13] X. Li, P. Prokopčáková and M. Palm, Mater. Sci. Eng. A, 611(2014), 234.

[14] F. Stein, M. Palm and G. Sauthoff, Intermetallics, 13(2005), 1275.

[15] P. Kratochvíl, P. Málek, M. Cieslar, P. Hanus, J. Hakl and T. Vlasák.T, Intermetallics, 15(2007), 333.

[16] A. Wasilkowska, M. Bartsch, F. Stein, M. Palm, K. Sztwiertnia, G. Sauthoff and U. Messerschmidt, Mater. Sci. Eng. A, 380(2004), 9.

[17] P. Lejček, A. Fraczkiewicz, Intermetallics, 11(2003), 1053.

[18] J.W. Cohron, Y. Lin, R.H. Zee and E. P. George, Acta Mater., 46(1998), 6245.

[19] F. Stein, A. Schneider and G. Frommeyer, Intermetallics, 11(2003), 71.

[20] D.A. Alven, N.S. Stoloff, Mater. Sci. Eng. A, 239-240(1997), 362.

[21] D.A. Alven, N.S. Stoloff, Scripta Mater., 34(1996), 1937.

[22] Y.D. Huang, W.Y. Yang and Z.Q. Sun, Intermetallics, 9(2001), 119.

[23] L. Anthony, B. Fultz, Acta Metall. Mater., 43(1995), 3885.   

[24] D.G. Morris, M.A. Muñoz-Morris, Intermetallics, 13(2005), 1269.

[25] H. Xiao, I. Baker, Scripta Metall. Mater., 28(1993), 1411.

[26] J.T. Guo, O. Jin, W.M. Yin and T.M. Wang, Scripta Metall. Mater., 29(1993), 783.

[27] K. Yoshimi, S. Hanada and M.H. Yoo, Acta Metall. Mater., 43(1995), 4141.

[28] M.H. Yoo, J.A. Horton and C.T. Liu, Acta Metall., 36(1988), 2935.