Effect of Mo Addition on the Microstructure and Properties of TiNiNb Alloy

doi:10.1007/s40195-014-0039-1

Abstract

Abstract:

The influence of Mo addition on the microstructure and properties of TiNiNb alloy with 4.5 at.% Nb has been investigated systemically. The experimental results indicated that the uniform distribution of Mo depresses the appearance of coarse β-Nb particles at the grain boundaries and short stripped texture consisting of abundant fine disperse Nb-rich particles appears around the grain boundaries. The yield strength of the alloy was enhanced from 450 to 600 MPa due to the solution strengthening of Nb and Mo and the elongation reached 18% when the Mo content is 0.5 at.%. At the same time, the shape memory effect of the alloy also is improved significantly by the Mo addition. The maximum recoverable strain of the alloy with 0.5 at.% Mo is near 8% and has reached the high level of Ni–Ti binary alloys. This novel high-strength alloy is promising to be used for high pressure tube and the macro-scale coupling with higher-quality requirements.

Key words: Shape memory alloy, Yield strength, Recoverable strain, Pipe coupling

Haichang Jiang, Ying Chen, Dan Yang, Hongding Sun, Jianmin Zeng, Lijian Rong. Effect of Mo Addition on the Microstructure and Properties of TiNiNb Alloy[J]. Acta Metallurgica Sinica (English Letters), 2014, 27(2): 217-222.

Figures/Tables 7

Fig. 1 SEM micrographs of the casting NiTiNb(Mo) alloys: a Ni49.8Ti45.7Nb4.5; b Ni49.2Ti45.8Nb4.5Mo0.5; c Ni48.5Ti46.0Nb4.5Mo1.0; d Ni47.9Ti46.1Nb4.5Mo1.5

Fig. 2 SEM micrograph of short strip phase in Ni47.9Ti46.1Nb4.5Mo1.5 alloy, A, B, and C indicate the zones for EDX analysis

Table 1 Results of EDX quantitative analysis of the phases in Ni47.9Ti46.1Nb4.5Mo1.5 alloys as indicated in Fig. 2 (in at.%)

Zone	Ti	Ni	Nb	Mo
A	49.07	45.31	5.08	0.54
B	48.38	43.39	7.76	0.47
C	12.61	15.07	70.06	2.26

Fig. 3 DSC cooling-heating curves of the Ni49.8-1.3xTi45.7+0.3xNb4.5Mox alloys

Fig. 4 Stress–strain curves of the Ni49.8-1.3xTi45.7+0.3xNb4.5Mox alloys at ambient temperature

Fig. 5 SEM images of fracture surfaces of tensile tested NiTiNb(Mo) alloys at ambient temperature: a Ni49.8Ti45.7Nb4.5; b Ni49.15Ti45.85Nb4.5Mo0.5; c Ni48.5Ti46.0Nb4.5Mo1.0; d Ni47.85Ti46.15Nb4.5Mo1.5

Fig. 6 Pre-deformation strain dependence of recoverable residual strain a recovery rate b of the Ni49.8-1.3xTi45.7+0.3xNb4.5Mox alloys (x = 0, 0.5, and 1.5)

References 18

[1]	C.S. Zhang, L.C. Zhao, T.W. Duerig, C.M. Wayman, Scr. Metall. Mater. 24, 1807(1990)10.1016/0956-716X(90)90550-Z
[2]	M. Piao, S. Miyazaki, K. Otsuka, Mater. Trans. 33, 346(1992)10.2320/matertrans1989.33.346
[3]	X.M. He, L.J. Rong, Scripta Mater. 51, 7(2004)10.1016/j.scriptamat.2004.03.027
[4]	W. Cai, X.L. Meng, L.C. Zhao, Curr. Opin. Solid State Mater. Sci. 9, 296(2005)10.1016/j.cossms.2006.07.002
[5]	K. Otsuka, X. Ren, Prog. Mater Sci. 50, 511(2005)10.1016/j.pmatsci.2004.10.001
[6]	M. Wang, M.Y. Jiang, G.Y. Liao, S. Guo, X.Q. Zhao, Prog. Nat. Sci. 22, 130(2012)10.1016/j.pnsc.2012.03.010
[7]	E. Choi, H.K. Hong, H.S. Kim, Y.S. Chung, J. Alloys Compd. 557, S444(2013)10.1016/j.jallcom.2012.02.037
[8]	X.Q. Zhao, X.M. Yan, Y.Z. Yang, H.B. Xu, Mater. Sci. Eng. A 438–400, 575(2006)10.1016/j.msea.2006.03.110
[9]	X.M. He, L.J. Rong, D.S. Yan, Y.Y. Li, Mater. Sci. Eng. A 371, 193(2004)10.1016/j.msea.2003.11.044
[10]	Y. Chen, H.C. Jiang, L.J. Rong, L. Xiao, X.Q. Zhao, Intermetallics 19, 217(2011)10.1016/j.intermet.2010.08.011
[11]	W. Liu, Q. Xu, F.S. Liu, Proc. Eng. 27, 1150(2012)10.1016/j.proeng.2011.12.565
[12]	Y. Chen, H.C. Jiang, S.W. Liu, L.J. Rong, X.Q. Zhao, Mater. Sci. Eng. A 512, 26(2009)10.1016/j.msea.2009.01.015
[13]	H.C. Jiang, L.J. Rong, Mater. Sci. Forum 546–549, 2127(2007)10.4028/www.scientific.net/MSF.546-549.2127
[14]	F. Liu, Z. Ding, Y. Li, H. Xu, Intermetallics 13, 357(2005)10.1016/j.intermet.2004.07.024
[15]	T.H. Nam, D.W. Chung, J.P. Noh, H.W. Lee, J. Mater. Sci. 36, 4181(2001)10.1023/A%3A1017964806065
[16]	G.B. Cho, T.Y. Kim, C.A. Yu, Y. Liu, T.H. Nam, J. Alloys Compd. 449, 129(2008)10.1016/j.jallcom.2006.02.083
[17]	K. Uchida, N. Shigenaka, T. Sakuma, Y. Sutou, K. Yamauchi, Mater. Trans. 48, 445(2007)10.2320/matertrans.48.445
[18]	V.É.GyunterG.N.DambaebvP.G.Sysolyatin, Medical Materials and Implants with Shape Memory Effect(Tomskii Gos. Univ., Tomsk, 1998), pp. 180–182