Skip to main content

Microstructure evolution of NiAl–Cr(Mo) planar eutectic lamellar structure during high temperature treatment

  • Lei Wang (a1), Luhan Gao (a1), Jun Shen (a2), Yunpeng Zhang (a1), Tao Wang (a1), Zewei Wang (a1), Pengfei Qu (a1), Jianying Zhang (a1) and Guojun Zhang (a1)...

The microstructure evolution of the directionally solidified NiAl–Cr(Mo) planar eutectic lamellar structure was studied at 1150 °C and times of up to 400 h. The planar eutectic lamellar structure is obtained at the withdrawal rate range of 2.5–7.5 μm/s. The interlamellar spacing decreases gradually with increasing the withdrawal rate. The lamellar termination (like angular or smooth) commonly exists in the as-DS alloy. After high temperature treatment, the lamellar structure at 2.5 μm/s (interlamellar spacing, 3.7 μm) is almost stable, only a little migration of termination occurs at 400 h. When the withdrawal rate increases to 4.5 μm/s, the coarsening and migration of termination occur at 200 h. The adjacently coarsened terminations assemble when the coarsening processes to a certain degree, thus resulting in the formation of the blocky Cr(Mo) phase. Similarly, the above instable phenomenon occurs at 7.5 μm/s. The relevant instability mechanisms are discussed.

Corresponding author
a)Address all correspondence to these authors. e-mail:
Hide All
1.Noebe, R.D., Bowman, R.R., and Nathal, M.V.: Physical and mechanical properties of the B2 compound NiAl. Int. Mater. Rev. 38, 193 (1993).
2.Johnson, D.R., Chen, X.F., Oliver, B.F., Noebe, R.D., and Whittenberger, J.D.: Processing and mechanical properties of in situ composites from the NiAl–Cr and the NiAl–(Cr,Mo) eutectic systems. Intermetallics 3, 99 (1995).
3.Amritesh, K., Charlotte, E., Antje, K., Michael, K., Oliver, K., and Ruth, S.: Micromechanical study on the deformation behavior of directionally solidified NiAl–Cr eutectic composites. J. Mater. Res. 32, 2127 (2017).
4.Misra, A. and Gibala, R.: Plasticity in multiphase intermetallics. Intermetallics 8, 1025 (2000).
5.Zhang, J.F., Ma, X.W., Ren, H.P., Chen, L., Jin, Z.L., Li, Z.L., and Shen, J.: Influence of growth rate on microstructural length scales in directionally solidified NiAl–Mo hypo-eutectic alloy. JOM 68, 178 (2016).
6.Bei, H. and George, E.P.: Microstructures and mechanical properties of a directionally solidified NiAl–Mo eutectic alloy. Acta Mater. 53, 69 (2005).
7.Wang, L. and Shen, J.: Effect of withdrawal rate on the microstructure and room temperature mechanical properties of directionally solidified NiAl–Cr(Mo)–(Hf, Dy)–4Fe alloy. J. Alloys Compd. 663, 187 (2016).
8.Sheng, L.Y., Guo, J.T., Tian, Y.X., Zhou, L.Z., and Ye, H.Q.: Microstructure and mechanical properties of rapidly solidified NiAl–Cr(Mo) eutectic alloy doped with trace Dy. J. Alloys Compd. 475, 730 (2009).
9.Wang, L., Shen, J., Zhang, Y.P., Xu, H.X., and Fu, H.Z.: Microstructure and mechanical properties of NiAl-based hypereutectic alloy obtained by liquid metal cooling and zone melted liquid metal cooling directional solidification techniques. J. Mater. Res. 31, 646 (2016).
10.Wang, L., Shen, J., Shang, Z., and Fu, H.Z.: Microstructure evolution and enhancement of fracture toughness of NiAl–Cr(Mo)–(Hf,Dy) alloy with a small addition of Fe during heat treatment. Scr. Mater. 89, 1 (2014).
11.Wang, L., Zhang, G.J., Shen, J., Zhang, Y.P., Xu, H.X., Ge, Y.H., and Fu, H.Z.: A true change of NiAl–Cr(Mo) eutectic lamellar structure during high temperature treatment. J. Alloys Compd. 732, 124 (2018).
12.Sheng, L.Y., Guo, J.T., Zhang, W., Xie, Y., Zhou, L.Z., and Ye, H.Q.: Effect of HIP and heat treatment on microstructure and compressive properties of rapidly solidified NiAl–Cr(Mo)–Hf eutectic alloy. Acta Metall. Sin. 45, 1025 (2009).
13.Chen, X.F., Johnson, D.R., Noebe, R.D., and Oliver, B.F.: Deformation and fracture of a directionally solidified NiAl–28Cr–6Mo eutectic alloy. J. Mater. Res. 10, 1159 (1995).
14.Yang, J.M., Jeng, S.M., Bain, K., and Amato, R.A.: Microstructure and mechanical behavior of in situ directional solidified NiAl/Cr(Mo) eutectic composite. Acta Mater. 45, 295 (1997).
15.Wang, L., Shen, J., Shang, Z., Zhang, J.F., Chen, J.H., and Fu, H.Z.: Effect of Dy on the microstructures of directionally solidified NiAl–Cr(Mo) hypereutectic alloy at different withdrawal rates. Intermetallics 44, 44 (2014).
16.Wang, L., Shen, J., Shang, Z., Zhang, J.F., Du, Y.J., and Fu, H.Z.: Microstructure and mechanical property of directionally solidified NiAl–Cr(Mo)–(Hf,Dy) alloy at different withdrawal rates. Mater. Sci. Eng., A 607, 113 (2014).
17.Wang, L., Shen, J., Zhang, Y.P., and Fu, H.Z.: Microstructure, fracture toughness and compressive property of as-cast and directionally solidified NiAl-based eutectic composite. Mater. Sci. Eng., A 664, 188 (2016).
18.Sheng, L.Y., Zhang, W., Guo, J.T., and Ye, H.Q.: Microstructure and mechanical properties of Hf and Ho doped NiAl–Cr(Mo) near eutectic alloy prepared by suction casting. Mater. Charact. 60, 1311 (2009).
19.Lin, L.Y. and Courtney, T.H.: Direct observations of lamellar fault migration in the Pb–Sn eutectic. Metall. Trans. 5, 513 (1974).
20.Graham, L.D. and Kraft, R.W.: Coarsening of eutectic microstructures at elevated temperatures. Trans. Metall. Soc. AIME 236, 94 (1966).
21.Eady, J.A. and Winegard, W.C.: Microstructural stability of the Pb–Sn eutectic. Can. Metall. Q. 10, 213 (1971).
22.Lin, L.Y., Courtney, T.H., and Ralls, K.M.: Deformation induced microstructural instability in the Pb–Sn eutectic. Acta Metall. 25, 99 (1977).
23.Racek, R. and Lesoult, G.: Ripening of Sn–Cd eutecticmicrostructures. J. Cryst. Growth 16, 223 (1972).
24.Kampe, J.C.M., Courtney, T.H., and Leng, Y.: Shape instabilities of plate-like structures—I. Experimental observations in heavily cold worked in situ composites. Acta Metall. 37, 1735 (1989).
25.Courtney, T.H. and Kampe, J.C.M.: Shape instabilities of plate-like structures—II. Analysis. Acta. Metall. 37, 1747 (1989).
26.Gali, A., Bei, H., and George, E.P.: Thermal stability of Cr–Cr3Si eutectic microstructures. Acta Mater. 57, 3823 (2009).
27.Livingston, J.D. and Cahn, J.W.: Discontinuous coarsening of aligned eutectoids. Acta. Acta Metall. 22, 495 (1974).
28.Sharma, G., Ramanujan, R.V., and Tiwari, G.P.: Instability mechanisms in lamellar microstructures. Acta Mater. 48, 875 (2000).
29.Wang, L., Shen, J., Zhang, G.J., Zhang, Y.P., Guo, L.L., Ge, Y.H., Gao, L.H., and Fu, H.Z.: Stability of lamellar structure of directionally solidified NiAl–28Cr–6Mo eutectic alloy at different withdrawal rates and temperatures. Intermetallics 94, 83 (2018).
30.Walter, J.L. and Cline, H.E.: Stability of the directionally solidified eutectics NiAl–Cr and NiAl–Mo. Metall. Trans. 4, 33 (1973).
31.Gali, A., Bei, H., and George, E.P.: Effects of boron on the microstructure and thermal stabilityof directionally solidified NiAl–Mo eutectic. Acta Mater. 58, 421 (2010).
Recommend this journal

Email your librarian or administrator to recommend adding this journal to your organisation's collection.

Journal of Materials Research
  • ISSN: 0884-2914
  • EISSN: 2044-5326
  • URL: /core/journals/journal-of-materials-research
Please enter your name
Please enter a valid email address
Who would you like to send this to? *



Full text views

Total number of HTML views: 5
Total number of PDF views: 8 *
Loading metrics...

Abstract views

Total abstract views: 53 *
Loading metrics...

* Views captured on Cambridge Core between 5th July 2018 - 21st July 2018. This data will be updated every 24 hours.