Effect of heat treatment on the microstructures and damping properties of biomedical Mg–Zr alloy

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Journal of Alloys and Compounds 509 (2011) 813–819

Contents lists available atScienceDirect

Journal of Alloys and Compounds

j o u r n a l h o m e p a g e :w w w . e l s e v i e r . c o m / l o c a t e / j a l l c o m

Effect of heat treatment on the microstructures and damping properties of

biomedical Mg–Zr alloy

Ming-Hung Tsai

a,b,c

_{, May-Show Chen}

c,d,e

_{, Ling-Hung Lin}

e,f

_{, Ming-Hong Lin}

a

_,

Ching-Zong Wu

e,f,∗∗

_{, Keng-Liang Ou}

c,g,h,∗

_{, Chih-Hua Yu}

c,h

a_{Department of Mechanical Engineering and Graduate Institute of Mechanical and Precision Engineering, National Kaoshiung University of Applied Sciences, Kaoshiung 807, Taiwan} b_{Department of Dentistry, Chang Yin dental clinic, No.46-1, Yangming St., Banqiao City, Taipei County 220, Taiwan}

c_{Research Center for Biomedical Devices, Taipei Medical University, Taipei 110, Taiwan} d_{School of Oral Hygiene, College of Oral Medicine, Taipei Medical University, Taipei 110, Taiwan} e_{Department of Dentistry, Taipei Medical University Hospital, Taipei 110, Taiwan}

f_{School of Dentistry, College of Oral Medicine, Taipei Medical University, Taipei 110, Taiwan}

g_{Graduated Institute of Biomedical Materials and Engineering, Taipei Medical University, Taipei 110, Taiwan} h_{Research Center for Biomedical Implants and Microsurgery Devices, Taipei Medical University, Taipei 110, Taiwan}

a r t i c l e i n f o

Article history: Received 11 June 2010 Received in revised form 16 September 2010 Accepted 18 September 2010 Available online 25 September 2010 Keywords: Mg–Zr alloy Microstructure Twining Damping capacity

a b s t r a c t

In this study, we elucidated the effect of heat treatment on the microstructures and damping proper-ties of the biomedical Mg–1 wt% Zr (K1) alloy by optical microscopy, transmission electron microscopy, energy-dispersive X-ray spectrometry, and experimental model analysis. The following microstructural transformation occurred when the as-quenched (AQ, i.e., solution heat treated and quenched) K1 alloy was subjected to aging treatment in the temperature range 200–500◦C:␣-Mg → (␣-Mg + twindense)→

(␣-Mg + twinloose)→ (␣-Mg + ␣-Zr). This microstructural transformation was accompanied by variations in

the damping capacity. The damping properties of the AQ K1 alloy subjected to aging treatment at 300◦C for 16 h were the best among those of the alloys investigated in the present study. The presence of twin structures in the alloy matrix was thought to play a crucial role in increasing the damping capacity of the K1 alloy. Hence, we state that a combination of solution treatment and aging is an effective means of improving the damping capacity of biomedical K1 alloys.

1. Introduction

The microstructures, mechanical properties, and corrosion resistance of Mg-based alloys have been studied widely by sev-eral researchers[1–5]. Addition of elemental Sr to Mg-based alloys results in grain reﬁnement and improvement of the mechanical properties of the alloys[6]. Dong et al.[7]have reported that upon the addition of 7 wt% Y, the ultimate tensile strength and yield strength of the Mg–7Li alloy become 120% and 152% of those of the as-cast Mg–7Li alloy, respectively. Moreover, addition of alloy-ing elements such as Al and rare-earth elements such as Nd, Re, and Pr to Mg-based alloys results in grain reﬁnement, grain bound-ary strengthening, and solid-solution strengthening[8–11]and a consequent improvement of the corrosion resistance of the alloys. Such improved Mg-based alloys can be used for manufacturing

∗ Corresponding author. Tel.: +886 2 27361661x5400; fax: +886 2 27395524. ∗∗ Corresponding author. Tel.: +886 2 27361661x5132.

E-mail addresses:[email protected](C.-Z. Wu),[email protected] (K.-L. Ou).

aerospace components, automobile parts, electronic goods, and sports goods[12,13].

Recently, Mg-based alloys have been identiﬁed as potential implant materials because of their high biodegradability[14,15] and excellent mechanical properties such as high strength-to-density ratio and low elastic modulus (close to that of bone tissues)[16]. Previous in vivo studies have shown that Mg, which is an essential component of the enzyme system in humans, is a degradable biomaterial that can be used in medical implants [15]. Therefore, several Mg-based alloys, including Mg–Al–Li–Ce [10], Mg–Al–Zn (AZ31 and AZ91)[11,12], Mg–Zn[17], Mg–Ca[18], Mg–Zn–Mn[19], and Mg–Si–(Zn, Ca)[20], have been developed, and the feasibility of using these alloys in biomedical applications has been investigated.

The K1 alloy has recently attracted considerable attention because it has high speciﬁc damping capacity, excellent mechanical properties, and high biodegradability and biocompatibility, which make it suitable for use as an implant material [21–25]. Gu et al. [24] have reported that the addition of Zr helps in increas-ing the strength and decreasincreas-ing the corrosion rate of the as-cast Mg–1Zr alloy. The results of hemocompatibility and cytotoxicity

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818 M.-H. Tsai et al. / Journal of Alloys and Compounds 509 (2011) 813–819

Fig. 11. BF image of the AQ K1 alloy aged at 300◦_{C for 8 h, which was taken from} the matrix in the [0 0 0 1] zone.

damping properties may be increased from the thermoelastic damping, magnetic damping, viscous damping, and defect damp-ing [41]. In conventional crystalline materials, defect damping contributes signiﬁcantly to the overall damping properties[42]. Material damping is extremely sensitive to the presence of defects.

Fig. 12. (a) BF image of the AQ K1 alloy aged at 500◦_{C for 16 h, which was taken} from the matrix in the [0 0 0 1] zone and (b) EDS spectrum taken from the island-like phase in (a).

The intrinsic movement of defects (of any type) under applied cyclic stress may give rise to internal friction, which in turn would cause energy dissipation. Four common types of defects are observed in polycrystalline metallic alloys: point defects, line defects, surface defects, and bulk defects[42]. The damping mechanism associ-ated with each of these defects is different. FromFig. 5(b), it is apparent that twin structures are present in the matrix of the alloy. The damping mechanism, which is responsible for vibration sup-pression, is similar for twin structures and surface defects, i.e., movement of the internal twin boundaries in the␣-Mg grains and resultant internal friction[25]. Twinning may enhance the rate of grain boundary sliding when new slip systems are activated after reorientation of the lattice atoms in the twinned areas[43]. More-over, a high density of twins may result in the formation of a large number of interface boundaries in the grains. Ustinov et al.[44] reported that the dissipative properties of nanotwinned Cu are mainly determined by the nature of the twinned substructures. With an increase in the twin boundary density, the nonlinear ampli-tude dependence of the logarithmic decrement becomes almost linear. Therefore, a high density of twin structures leads to rapid and marked enhancement of the damping capacity. Hence, it is reason-able to state that the twin structures play a crucial role in increasing the damping capacity of the K1 alloy. More tests must be carried out on the microstructural characteristics, mechanical properties, cytotoxicity, and biocompatibility of the K1 alloy before it is used in clinical applications.

4. Conclusions

There was no notable difference in the microstructure and damping properties of the AQ K1 alloy before and after aging treat-ment at 200◦C. When the AQ K1 alloy was subjected to aging treatment at 300◦C for 8 h, some twins were formed in the␣-Mg grains. Moreover, the number of twins increased with the soaking period. The AQ K1 alloy aged at 300◦C for 16 h had the best damping properties among all the samples considered in this study. The aver-age f and values of this alloy were 380 Hz and 0.1724, respectively. When the AQ K1 alloy was aged at 400◦C, coarse and loose twin structures were formed within the␣-Mg grains. These twin struc-tures caused degradation of the damping properties of the alloy. Upon aging at temperatures higher than 500◦C, the microstructure of this alloy was found to comprise both␣-Mg and ␣-Zr phases. However, the␣-Zr phase had no signiﬁcant inﬂuence on the damp-ing properties of the K1 alloy.

Acknowledgements

The authors would like to thank the Center of Excellence for Clinical Trial and Research in Neurology and Neurosurgery, Taipei Medical University-Wan Fang Hospital for ﬁnancially supporting this research under contract No. DOH99-TD-B-111-003 and sup-ported partly by Alliance Global Technology Co., LTD.

References

[1] M. Sun, G. Wu, J. Dai, W. Wang, W. Ding, J. Alloys Compd. 494 (2010) 426. [2] B. Jiang, D. Qiu, M.-X. Zhang, P.D. Ding, L. Gao, J. Alloys Compd. 492 (2010) 95. [3] J. Gubicza, K. Máthis, Z. Heged ˝us, G. Ribárik, A.L. Tóth, J. Alloys Compd. 492

(2010) 166.

[4] E.N. El Sawy, H.A. El-Sayed, H.A. El Shayeb, J. Alloys Compd. 492 (2010) 69. [5] L. Wang, T. Shinohara, B.-P. Zhang, J. Alloys Compd. 496 (2010) 500. [6] H. Liu, Y. Chen, H. Zhao, S. Wei, W. Gao, J. Alloys Compd. 504 (2010) 345. [7] H. Dong, L. Wang, Y. Wu, L. Wang, J. Alloys Compd. 506 (2010) 468. [8] Z. Wen, C. Wu, C. Dai, F. Yang, J. Alloys Compd. 488 (2009) 392.

[9] J. Zhang, K. Liu, D. Fang, X. Qiu, P. Yu, D. Tang, J. Meng, J. Alloys Compd. 480 (2009) 810.

[10] L. Gao, C. Zhang, M. Zhang, X. Huang, N. Sheng, J. Alloys Compd. 468 (2009) 285. [11] J. Zhang, J. Wang, X. Qiu, D. Zhang, Z. Tian, X. Niu, D. Tang, J. Meng, J. Alloys

(3)

M.-H. Tsai et al. / Journal of Alloys and Compounds 509 (2011) 813–819 819 [12] B.L. Mordike, T. Ebert, Mater. Sci. Eng. A 302 (2001) 37.

[13] T. Kaneko, M. Suzuki, Mater. Sci. Forum 419–422 (2003) 67.

[14] F. Witte, J. Fischer, J. Nellesen, H.-A. Crostack, V. Kaese, A. Pisch, Biomaterials 27 (2006) 1013.

[15] F. Witte, V. Kaese, H. Haferkamp, E. Switzer, A. Meyer-Lindenberg, C.J. Wirth, H. Windhagen, Biomaterials 26 (2005) 3557.

[16] M.P. Staiger, A.M. Pietak, J. Huadmai, G. Dias, Biomaterials 27 (2006) 1728.

[17] S. Zhang, J. Li, Y. Song, C. Zhao, X. Zhang, C. Xie, Y. Zhang, H. Tao, Y. He, Y. Jiang, Y. Bian, Mater. Sci. Eng. C 29 (2009) 1907.

[18] Z. Li, X. Gu, S. Lou, Y.F. Zheng, Biomaterials 29 (2008) 1329.

[19] E. Zhang, D. Yin, L. Xu, L. Yang, K. Yang, Mater. Sci. Eng. C 29 (2009) 987. [20] E. Zhang, L. Yang, J. Xu, H. Chen, Acta Biomater. 6 (2010) 1756. [21] M. Qian, Acta Mater. 55 (2007) 943.

[22] M. Qian, Acta Mater. 54 (2006) 2241.

[23] F. Witte, N. Hort, C. Vogt, S. Cohen, K.U. Kainer, R. Willumeit, F. Feyerabend, Curr. Opin. Solid State Mater. Sci. 12 (2008) 63.

[24] X. Gu, Y. Zheng, Y. Cheng, S. Zhong, T. Xi, Biomaterials 30 (2009) 484. [25] S.H. Baik, Nucl. Eng. Des. 198 (2000) 241.

[26] J. Nagels, M. Stokdijk, P.M. Rozing, J. Shoulder Elbow Surg. 12 (2003) 35. [27] P.L.S. Li, N.B. Jones, P.J. Gregg, Med. Eng. Phys. 18 (7) (1996) 596.

[28] M.B. Nasab, M.R. Hassan, Trends Biomater. Artif. Organs 24 (1) (2010) 69. [29] M. Long, H.J. Rack, Biomaterials 19 (1998) 1621.

[30] T. Sumitomo, C.H. Cáceres, M. Veidt, J. Light Met. 2 (2002) 49. [31] S. Ganeshan, S.L. Shang, Y. Wang, Z.-K. Liu, Acta Mater. 57 (2009) 3876. [32] K. Nishiyamaa, R. Matsui, Y. Ikeda, S. Niwa, T. Sakaguchid, J. Alloys Compd. 355

(2003) 22.

[33] B.T. Wang, Mech. Syst. Signal Process. 12 (5) (1998) 627.

[34] P.W. Peng, K.L. Ou, C.Y. Chao, Y.N. Pan, C.H. Wang, J. Alloys Compd. 490 (2010) 661.

[35] D.G. Lee, S. Lee, Y. Lee, Mater. Sci. Eng. A 486 (2008) 19. [36] D.Q.J. Wan, C. Wang, G.C. Yang, Mater. Sci. Eng. A 517 (2009) 114.

[37] L. Capolungoa, I.J. Beyerlein, G.C. Kaschner, C.N. Tomé, Mater. Sci. Eng. A 513–514 (2009) 42.

[38] L. ˇCíˇzek, L. Pawlica, R. Kocich, M. Janoˇsec, T. Ta ´nski, M. Pra ´zmowski, J. Arch. Mater. Manuf. Eng. 27 (2008) 127.

[39] Z. Luo, S. Zhang, Acta Metall. Sin. 6 (1993) 337. [40] G.L. Liu, Acta Phys. Sin. 57 (1043) (2008) (in Chinese).

[41] Z.M. Zhang, J.H. Wang, G.C. Yang, Y.O. Zhou, J. Mater. Sci. 35 (2000) 3383. [42] I.G. Ritchie, Z.-L. Pan, Metall. Trans. A 22A (1991) 607.

[43] L. Lin, W. Wu, Y. Lin, L. Chen, Z. Liu, J. Mater. Sci. 41 (2006) 409. [44] A.I. Ustinov, V.S. Skorodzievski, E.V. Fesiun, Acta Mater. 56 (2008) 3770.