Influence of laser surface remelting on microstructure and degradation mechanism in simulated body fluid of Zn-0.5Zr alloy

doi:10.1016/j.jmst.2019.05.019

Abstract

Abstract:

In this study, the Zn-0.5 wt%Zr (Zn-Zr) alloy was treated by laser surface remelting (LSR), and then the microstructure and degradation mechanism of the remelting layer were investigated and compared with the original as-cast alloy. The results reveal that after LSR, the bulky Zn₂₂Zr phase in the original Zn-Zr alloy is dissolved and the coarse equiaxed grains transform into fine dendrites with a secondary dendrite arm space of about 100 nm. During the degradation process in simulated body fluid (SBF), the corrosion products usually concentrate at some certain areas in the original alloy, while the corrosion products distribute uniformly and loosely in the LSR-treated surface. After removing the corrosion products, it was found that the former suffers obvious pitting corrosion and then localized corrosion. The proposed mechanism is that corrosion initiates at grain boundaries and develops into the depth at some locations, and then leads to localized corrosion. For the LSR-treated sample, corrosion initiates at some active sites and propagates in all directions, corrosion takes place in the whole surface with distinctly uniform thickness reduction, while the localized corrosion and peeling of bulky Zn₂₂Zr particles were eliminated. The electrochemical results also suggest the uniform corrosion of LSR-treated sample and localized corrosion of original sample. Based on the results, a new approach to regulate the corrosion mode of the biodegradable Zn alloy is proposed.

Key words: Biodegradable Zn alloy, Laser surface remelting, Microstructure, Degradation mechanism

Zheng Wang, Qingke Zhang, Robabeh Bagheri, Pushan Guo, Yirong Yao, Lijing Yang, Zhenlun Song. Influence of laser surface remelting on microstructure and degradation mechanism in simulated body fluid of Zn-0.5Zr alloy[J]. J. Mater. Sci. Technol., 2019, 35(11): 2705-2713.

Figures/Tables 9

Fig. 1. XRD patterns of original and LSR-treated samples.

Fig. 2. Surface microstructures of (a), (b) the original sample and the corresponding element distribution of (c) Zn and (d) Zr in (b).

Fig. 3. Surface microstructures of the LSR-treated sample: (a) in air and (b) with Ar gas shielding; (c), (d) microstructure of the remelting layer and the corresponding distribution of (e) Zn (f) Zr in (c).

Fig. 4. Surface morphologies of the original samples following immersion in SBF for 5, 12, and 20 days: (a), (c), (e) with corrosion products, (b), (d), (f) after removal of the corrosion products.

Fig. 5. Surface morphologies of the LSR-treated samples following immersion in SBF for 5, 12, and 20 days: (a), (c), (e) with corrosion products; (b), (d), (f) after removal of the corrosion products.

Fig. 6. XPS spectra: survey scan for (a) samples before immersion, (b) corrosion products of samples after immersion for 20 days and detail scan for corrosion products of original sample (c) Zn 2p, (d) C 1s, (e) P 2p and (f) O 1s.

Fig. 7. Nyquist diagram and Bode plots of samples immersed in SBF for (a), (b) 15 min and (c), (d) 20 days; equivalent circuits proposed for original sample immersed in SBF for (e) 15 min and (f) 20 days and LSR-treated samples immersed in SBF (g) for 15 min and (h) for 20 days.

Table 1 EIS results of original and LSR-treated samples after immersed in SBF for different times.

Samples	R_s (Ω cm²)	Q_f		R_f (Ω cm²)	Q_dl		R_ct (Ω cm²)	W-R	W-T	W-P	Q_pit		R_pit (Ω cm²)
		T × 10^-5 (Ω^-1 cm^-2 Sⁿ)	P		T (Ω^-1 cm^-2 Sⁿ)	P					T (mΩ^-1 cm^-2 Sⁿ)	P
Original-15 min	13.06	9.47	0.71	401	0.045	0.62	368.3	368	4	0.5	-	-	-
LSR treated-15 min	18.89	1.45	0.75	260	0.0033	0.53	986.3	-	-	-	-	-	-
Original-20 days	6.27	6.15	0.52	69.1	0.00012	0.72	182.6	-	-	-	0.02534	0.74	460.5
LSR treated-20 days	10	0.14	0.75	1005	0.0030	0.66	207.7	945	234	0.51	-	-	-

Fig. 8. Schematic diagram on corrosion of the (a)-(c) original and (d)-(f) LSR-treated samples in SBF.

References

[1]	Y.F. Zheng, X.N. Gu, F. Witte, Mat. Sci. Eng. R 77 (2014) 1-34.
[2]	X. Liu, J. Sun, K. Qiu, Y. Yang, Z. Pu, L. Li, Y. Zheng, J. Alloy Compd. 664(2016)444-452.
[3]	M.M. Alves, P. Tomáˇs, C.F. Santos, M.F. Montemor, RSC Adv. 7(2017)28224-28233.
[4]	P. Sotoudeh Bagha, S. Khaleghpanah, S. Sheibani, M. Khakbiz, A. Zakeri, J.Alloys Compd. 735(2018) 1319-1327.
[5]	M. Moravej, D. Mantovani, Int. J. Mol. Sci. 12(2011) 4250-4270.
[6]	Y. Onuma, P.W. Serruys, Circulation 123 (2011) 779-797.
[7]	H. Gong, K. Wang, R. Strich, J.G. Zhou, J. Biomed. Mater. Res. B 103 (2015)1632-1640.
[8]	J.A. Grogan, B.J.O. Brien, S.B. Leen, P.E. McHugh, Acta Biomater. 7(2011)3523-3533.
[9]	Z. Shi, J. Yu, X. Liu, L. Wang, J. Mater.Sci.Technol. 34(2018) 1008-1015.
[10]	C. Wang, H.T. Yang, X. Li, Y.F. Zheng, J. Mater.Sci.Technol. 32(2016)909-918.
[11]	Y. Chen, W. Zhang, M.F. Maitz, M. Chen, H. Zhang, J. Mao, Y. Zhao, N. Huang, G. Wan, Corros. Sci. 111(2016) 541-555.
[12]	W.R.O. Xf, Cheung, E. Spinelli, K.S. Cruz, A. Garci, Appl. Surf. Sci. 254(2008)2763-2770.
[13]	C. Ma, G. Peng, L. Nie, H. Liu, Y. Guan, Appl. Surf. Sci. 445(2018) 211-216.
[14]	D.C. Florian, M.A. Melia, F.W. Steuer, B.F. Briglia, M.K. Purzycki, J.R. Scully, J.M.Fitz-Gerald, Biointerphases 12 (2017) 21003.
[15]	C. Shuai, Y. Yang, P. Wu, X. Lin, Y. Liu, Y. Zhou, P. Feng, X. Liu, S. Peng, J. AlloyCompd. 691(2017) 961-969.
[16]	L. Müller, F.A. Müller, Acta Biomater. 2(2006) 181-189.
[17]	H. Okamoto, J. Phase Equilib.Diff. 28(2007) 236-237.
[18]	J. Winiarski, W. Tylus, B. Szczygie?, Appl. Surf. Sci. 364(2016) 455-466.
[19]	L. Yang, N. Hort, D. Laipple, D. H?che, Y. Huang, K.U. Kainer, R. Willumeit, F. Feyerabend, Acta Biomater. 9(2013) 8475-8487.
[20]	E. Diler, B. Lescop, S. Rioual, G. Nguyen Vien, D. Thierry, B. Rouvellou, Corros.Sci. 79(2014) 83-88.
[21]	H. Yang, C. Wang, C. Liu, H. Chen, Y. Wu, J. Han, Z. Jia, W. Lin, D. Zhang, W. Li,W. Yuan, H. Guo, H. Li, G. Yang, D. Kong, D. Zhu, K. Takashima, L. Ruan, J. Nie,X. Li, Y. Zheng, Biomaterials 145 (2017) 92-105.
[22]	L. Liu, Y. Meng, C. Dong, Y. Yan, A.A. Volinsky, L. Wang, J. Mater. Sci.Technol.34(2018) 2271-2282.
[23]	B. Zberg, P.J. Uggowitzer, J.F. L?ffler, Nat. Mater. 8(2009) 887-891.
[24]	E. Mostaed, M. Sikora-Jasinska, A. Mostaed, S. Loffredo, A.G. Demir, B.Previtali, D. Mantovani, R. Beanland, M. Vedani, J. Mech. Behav. Biomed. 60(2016) 581-602.
[25]	L. Bai, G. Le, X. Liu, J. Li, S. Xia, X. Li, J. Alloy Compd. 745(2018) 716-724.
[26]	Z. Liu, Z. Wang, J. Mater. Sci. Technol. 34(2018) 2116-2124.
[27]	T. Haxhimali, A. Karma, F. Gonzales, M. Rappaz, Nat. Mater. 5(2006)660-664.
[28]	W. Wang, P.D. Lee, M. McLean, Acta Mater. 51(2003) 2971-2987.
[29]	M. Mokaddem, P. Volovitch, K. Ogle, Electrochim. Acta2255 (2010)7867-7875.
[30]	A.G. Marques, M.G. Taryba, A.S. Pan?o, S.V. Lamaka, A.M. Sim?es, Corros. Sci.104(2016) 123-131.
[31]	P. Marcus, V. Maurice, H.H. Strehblow, Corros. Sci. 50(2008) 2698-2704.
[32]	S. Bauer, P. Schmuki, K. von der Mark, J.Park, Prog. Mater. Sci. 58(2013)261-326.
[33]	A.J. Drelich, P.K. Bowen, L. Lalonde, J. Goldman, J.W. Drelich, Surf. Innov. 4(2016) 133-140.
[34]	P.K. Bowen, J. Drelich, J. Goldman, Adv. Mater. 25(2013) 2577-2582.
[35]	S. Zhao, J. Seitz, R. Eifler, H.J. Maier, R.J. Guillory, E.J. Earley, A. Drelich, J.Goldman, J.W. Drelich, Mater. Sci. Eng. C 76 (2017) 301-312.
[36]	J. Lv, J. Mater. Sci .Technol. 34(2018) 1685-1691.