Mechanical properties of CoSn2 and α-CoSn3 intermetallic compounds: first-principles calculations and nano-indentation measurements
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Structural stability and mechanical properties of CoSn2 and α-CoSn3 intermetallic compounds (IMCs) were investigated by first-principles calculations and nano-indentation measurements. The systematical works of the phase stability, elastic constants, and electronic structures were carried out to understand the mechanical properties of CoSn2 and α-CoSn3 IMCs. The results showed that the calculated Young’s modulus of CoSn2 and α-CoSn3 was 149.36 and 138.51 GPa, respectively. In both cases, the major contribution to total density of states (DOS) was Co-d, Sn-s, and Sn-p states and ionic bonds formed between nearest-neighbor Co and Sn atoms. The analyses about electronic structures indicated that the bonding strength of Co–Sn in α-CoSn3 was stronger than that in CoSn2, which made it easy to understand the differences of phase stability and mechanical properties between CoSn2 and α-CoSn3 IMCs. By means of nano-indentation, the Young’s modulus and hardness were measured to be 151.90 ± 7.21 GPa and 6.43 ± 0.46 GPa for CoSn2 IMC, while 144.3 ± 8.36 GPa and 6.28 ± 0.63 GPa for α-CoSn3, respectively. By combining experimental methods and first-principles, it was clearly illustrated that the mechanical properties of CoSn2 were better than that of α-CoSn3.
This work was supported by the National Natural Science Foundation of China (Nos. 51465039 and 51765040), Natural Science Foundation of Jiangxi Province (20161BAB206122).
- 3.Y. Tang, G.Y. Li, D.Q. Chen, Y.C. Pan, Influence of TiO2 nanoparticles on IMC growth in Sn-3.0Ag-0.5Cu-xTiO2 solder joints during isothermal aging process. J. Mater. Sci. 25, 981–991 (2014)Google Scholar
- 23.M. Armbrüster, M. Schmidt, R. Cardosogil, H. Borrmann, Y. Grin, Crystal structures of iron distannide, FeSn2, and cobalt distannide, CoSn2. Zeitschrift für Kristallographie New Cryst. Struct. 222, 83–84 (2007)Google Scholar
- 24.A. Lang, W. Jeitschko, Two new phases in the system cobalt-tin: the crystal structures of α- and β-CoSn3. Zeitschrift Für Metall. 87, 759–764 (1996)Google Scholar
- 30.W. Dong, D. Shen, S. Yang, B. Liang, X. Wang, Y. Liu et al., First-principles study of mechanical and electronic properties of Co–Sn intermetallics for lithium ion battery anode. Chem. Res. Chin. U. 8, 1–6 (2018)Google Scholar
- 39.D. Yang, J. Cai, Q. Wang, J. Li, Y. Hu, L. Li, Significantly enhanced shear strength of Sn–Ag–Cu/Co–P ball grid array solder joints by CoSn3 intermetallic compound, in Proceedings of Electronic System-Integration Technology Conference (IEEE, 2016), pp. 1–7Google Scholar
- 40.D. Tabor, in The Hardness of Metals (Oxford University Press, Oxford, 1951), pp. 67–83Google Scholar