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

Subject Areas : Journal of Environmental Friendly Materials

M. Rajabi ¹ , M. Shahmiri ² , M. Ghanbari ³

1 - School of Metallurgy and Materials Engineering, Iran University of Science and Technology, Tehran, Iran.
2 - School of Metallurgy and Materials Engineering, Iran University of Science and Technology, Tehran, Iran.
3 - School of Metallurgy and Materials Engineering, Iran University of Science and Technology, Tehran, Iran.

Received: 2017-05-05 Accepted : 2017-05-05 Published : 2017-03-01

Keywords:

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.

References:

[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.