Effect of Carbon Nanotube Orientation on Mechanical Properties and Thermal Expansion Coefficient of Carbon Nanotube-Reinforced Aluminum Matrix Composites

doi:10.1007/s40195-014-0136-1

Abstract

Abstract:

Carbon nanotube-reinforced 2009Al (CNT/2009Al) composites with randomly oriented CNTs and aligned CNTs were fabricated by friction stir processing (FSP) and FSP-rolling, respectively. The CNT/2009Al composites with aligned CNTs showed much better tensile properties at room temperature and elevated temperature compared with those with the randomly oriented CNTs, which is mainly attributed to larger equivalent aspect ratio of the CNTs and avoidance of preferential fracture problems. However, much finer grain size was not beneficial to obtaining high strength above 473 K. The aligned CNTs resulted in tensile anisotropy, with the best tensile properties being achieved along the direction of CNT aligning. As the off-axis angle increased, the tensile properties were reduced due to the weakening of the load transfer ability. Furthermore, aligned CNTs resulted in much lower coefficient of thermal expansion compared with randomly oriented CNTs.

Key words: Carbon nanotubes, Metal matrix composites, Mechanical properties, Coefficient of thermal expansion, Friction stir processing

Y. Liu Z., L. Xiao B., G. Wang W., Y. Ma Z.. Effect of Carbon Nanotube Orientation on Mechanical Properties and Thermal Expansion Coefficient of Carbon Nanotube-Reinforced Aluminum Matrix Composites[J]. Acta Metallurgica Sinica (English Letters), 2014, 27(5): 901-908.

Figures/Tables 9

Fig. 1 Morphology of the as-received CNTs

Fig. 2 SEM images showing CNT distribution in FSP a and FSP-rolled b 1.5 vol% CNT/2009Al composites, and HRTEM image showing CNT in FSP-rolled 4.5 vol% CNT/2009Al composite c

Fig. 3 Variation of tensile properties of the aligned composites with off-axis angle

Fig. 4 Fractographs of composites with 4.5 vol% aligned CNTs with different off-axis angles: a 0°; b 45°; c 90°

Table 1 CNT aspect ratios, grain sizes, and tensile properties of CNT/2009Al composites with different CNT orientations

CNT orientation	CNT content (vol%)	Grain size (μm)	s	YS (MPa)	UTS (MPa)	El (%)
Random orientation	0	4.0	-	298	409	16
	1.5	1.2	15	385	477	7
	4.5	0.8	15	435	466	2
Aligned orientation	0	4.0	-	311	415	15
	1.5	3.0	30	380	480	12
	3.0	0.8	30	470	600	10
	4.5	0.5	30	570	640	5

Fig. 5 Moduli of the CNT/2009Al composites with different CNT orientations

Fig. 6 Elevated temperature tensile properties of the CNT/2009Al composites

Fig. 7 Fractographs of composites with 1.5 vol% random CNT at 373 K a and 573 K b, and composites with 4.5 vol% aligned CNT at 373 K c and 573 K d

Fig. 8 Variation of normalized CTE of the random and aligned composites with CNT concentration

References 29

[1]	D.B. Miracle,Compos. Sci. Technol. 65, 2526(2005)
[2]	J.M. Torralba, C.E. da Costa, F. Velasco, J. Mater. Process. Technol. 133, 203(2003)
[3]	Z.Y. Liu, Q.Z. Wang, B.L. Xiao, Z.Y. Ma, Y. Liu,Acta Metall. Sin. 46, 1121(2010). (in Chinese)
[4]	J.S. Moya, S. Lopez-Esteban, C. Pecharroman,Prog. Mater Sci. 52, 1017(2007)
[5]	P. Ajayan, O. Zhou, Applications of Carbon Nanotubes (Springer, Berlin, 2001), p. 391
[6]	M. Trojanowicz,Trends Anal. Chem. 25, 480(2006)
[7]	A. Krishnan, E. Dujardin, T.W. Ebbesen, P.N. Yianilos, M.M.J. Treacy, Phys. Rev. B 58, 14013 (1998)
[8]	Z. Han, A. Fina,Prog. Polym. Sci. 36, 914(2011)
[9]	E.T. Thostenson, Z. Ren, T.W. Chou,Compos. Sci. Technol. 61, 1899(2001)
[10]	S.R. Bakshi, D. Lahiri, A. Agarwal,Int. Mater. Rev. 55, 41(2010)
[11]	T. Kuzumaki, K. Miyazawa, H. Ichinose, K. Ito, J. Mater. Res. 13, 2445(1998)
[12]	Z.Y. Liu, S.J. Xu, B.L. Xiao, P. Xue, W.G. Wang, Z.Y. Ma, Compos. A 43, 2161 (2012)
[13]	S.J. Xu, B.L. Xiao, Z.Y. Liu, W.G. Wang, Z.Y. Ma,Acta Metall. Sin. 48, 882(2012). (in Chinese)
[14]	H.J. Choi, J.H. Shin, B.H. Min, J.S. Park, D.H. Bae, J. Mater. Res. 24, 2610(2009)
[15]	D.H. Nam, S.I. Cha, B.K. Lim, H.M. Park, D.S. Han, S.H. Hong, Carbon 50, 2417 (2012)
[16]	D.H. Nam, Y.K. Kim, S.I. Cha, S.H. Hong, Carbon 50, 4809 (2012)
[17]	L. Jiang, G. Fan, Z. Li, X. Kai, D. Zhang, Z. Chen, S. Humphries, G. Heness, W.Y. Yeung, Carbon 49, 1965 (2011)
[18]	L. Cao, Z. Li, G. Fan, L. Jiang, D. Zhang, W.J. Moon, Y.S. Kim, Carbon 50, 1057 (2012)
[19]	C. He, N. Zhao, C. Shi, X. Du, J. Li, H. Li, Q. Cui,Adv. Mater. 19, 1128(2007)
[20]	Z.Y. Liu, B.L. Xiao, W.G. Wang, Z.Y. Ma, Carbon 50, 1843 (2012)
[21]	Z.Y. Liu, B.L. Xiao, W.G. Wang, Z.Y. Ma,Compos. Sci. Technol. 72, 1826(2012)
[22]	Z.Y. Liu, B.L. Xiao, W.G. Wang, Z.Y. Ma, Carbon 62, 35 (2013)
[23]	Z.Y. Liu, B.L. Xiao, W.G. Wang, Z.Y. Ma, Carbon 69, 264 (2014)
[24]	K.T. Kim, J. Eckert, G. Liu, J.M. Park, B.K. Lim, S.H. Hong,Scr. Mater. 64, 181(2011)
[25]	R.S. Mishra, Z.Y. Ma, Mater. Sci. Eng. R 50, 1 (2005)
[26]	Z.Y. Ma, Metall. Mater. Trans. A 39, 642 (2008)
[27]	H. Kwon, M. Estili, K. Takagi, T. Miyazaki, A. Kawasaki, Carbon 47, 570 (2009)
[28]	M. Nganbe, M. Heilmaier,Int. J. Plast. 25, 822(2009)
[29]	T.W. Clyne, P.J. Withers,An Introduction to Metal Matrix Composites (Cambridge University Press, Cambridge, 1993), p. 120