Hostname: page-component-586b7cd67f-2plfb Total loading time: 0 Render date: 2024-11-24T13:53:12.987Z Has data issue: false hasContentIssue false

Strain rate and temperature effects on dynamic properties of high-strength weldable aluminum-scandium alloy

Published online by Cambridge University Press:  31 January 2011

Woei-Shyan Lee*
Affiliation:
Department of Mechanical Engineering, National Cheng Kung University, Tainan 701, Taiwan, Republic of China
Tao-Hsing Chen
Affiliation:
Department of Mechanical Engineering, National Cheng Kung University, Tainan 701, Taiwan, Republic of China
*
a) Address all correspondence to this author. e-mail: [email protected]
Get access

Abstract

The dynamic mechanical behavior, fracture characteristics, and microstructural evolution of high-strength weldable aluminum-scandium (Al–Sc) alloy were investigated using a compressive split Hopkinson pressure bar at strain rates of 1.3 × 103, 3.6 × 103, and 5.9 × 103 s−1, respectively, and temperatures of −100, 25, and 300 °C. The results showed that the flow stress, work hardening rate, and strain rate sensitivity increase with increasing strain rate but decrease with increasing temperature. Conversely, the activation volume and activation energy increase as the temperature increases or the strain rate decreases. Moreover, the fracture strain decreases with increasing strain rate and decreasing temperature. It was shown that the Zerilli–Armstrong face-centered-cubic (fcc) constitutive equation provides accurate predictions of the mechanical response of the Al–Sc alloy under the considered strain rate and temperature conditions. Scanning electron microscopy observations revealed that the fracture surfaces of the impacted specimens are characterized by transgranular dimpled features, which are indicative of a ductile failure mode. Moreover, transmission electron microscopy observations indicated the presence of both fine and coarse randomly dispersed precipitates within the matrix and at the grain boundaries. It was found that an increasing strain rate reduces the size of the dislocation cells within the impacted Al–Sc microstructure and therefore increases the dislocation density. However, at higher temperatures, the dislocations are annihilated, leading to a reduction in the dislocation density and a corresponding increase in the dislocation cell size. The variations observed in the size and density of the dislocation cells were found to be consistent with the dynamic tendencies noted in the stress–strain response of the Al–Sc alloy.

Type
Articles
Copyright
Copyright © Materials Research Society 2009

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1.Ferry, M., Burhan, N.: Microstructural evolution in a fine-grained Al–0.3 wt% Sc alloy produced by severe plastic deformation. Scr. Mater. 56, 525 2007CrossRefGoogle Scholar
2.Kim, J.H., Kim, J.H., Yeom, J.T., Lee, D.G., Lim, S.G., Park, N.K.: Effect of scandium content on the hot extrusion of Al–Zn–Mg–(Sc) alloy. J. Mater. Process. Technol. 187–188, 635 2007CrossRefGoogle Scholar
3.Kramer, L.S., Tack, W.T., Fernandes, M.T.: Scandium in aluminum alloys. Adv. Mater. Process. 152, 23 1997Google Scholar
4.Irving, B.: Scandium places aluminum welding on a new plateau. Weld. J. 76, 53 1997Google Scholar
5.Regazzoni, G., Kocks, U.F., Follansbees, P.S.: Dislocation kinetics at high strain rates. Acta Metall. 35, 2865 1987CrossRefGoogle Scholar
6.Jindal, V., De, P.K., Venkateswarlu, K.: Effect of Al3Sc precipitates on the work hardening behavior of aluminum–scandium alloys. Mater. Lett. 60, 3373 2006CrossRefGoogle Scholar
7.Karnesky, R.A., van Dalen, M.E., Dunand, D.C., Seidman, D.N.: Effects of substituting rare-earth elements for scandium in a precipitation-strengthened Al–0.08 at.% Sc alloy. Scr. Mater. 55, 437 2006CrossRefGoogle Scholar
8.Seidman, D.N., Marquis, E.A., Dunand, D.C.: Precipitation strengthening at ambient and elevated temperatures of heat-treatable Al(Sc) alloys. Acta Mater. 50, 4021 2002CrossRefGoogle Scholar
9.Riddle, Y.W., Sanders, T.H. Jr.: A study of coarsening, recrystallization, and morphology of microstructure in Al–Sc–(Zr)–(Mg) alloys. Metall. Mater. Trans . A 35, 341 2004CrossRefGoogle Scholar
10.Jones, M.J., Humphreys, F.J.: Interaction of recrystallization and precipitation: The effect of Al3Sc on the recrystallization behavior of deformed aluminium. Acta Mater. 51, 2149 2003CrossRefGoogle Scholar
11.Lathabai, S., Lloyd, P.G.: The effect of scandium on the microstructure, mechanical properties and weldability of a cast Al–Mg alloy. Acta Mater. 50, 4275 2002CrossRefGoogle Scholar
12.Paglia, C.S., Jata, K.V., Buchheit, R.G.: A cast 7050 friction stir weld with scandium: Microstructure, corrosion and environmental assisted cracking. Mater. Sci. Eng., A 424, 196 2006CrossRefGoogle Scholar
13.Yushchenko, K.A., Ishchenko, A.Y., Tretyak, N.G., Lozovskaya, A.V., Sklabinskaya, I.E.: Effect of scandium on weldability and properties of welded joints in aluminum-magnesium-lithium system alloys. Welding in the World 35, 48 1995Google Scholar
14.Davydov, V.G., Elagin, V.I., Zakharov, V.V., Rostova, T.D.: Alloying aluminum alloys with scandium and zirconium additives. Metal Sci. Heat Treat. 38, 347 1996CrossRefGoogle Scholar
15.Lee, W.S., Chen, T.H.: Dynamic mechanical response and microstructural evolution of high strength aluminum-scandium (Al–Sc) alloy. Mater. Trans. 47, 355 2006CrossRefGoogle Scholar
16.Chiddister, J.L., Malvern, L.E.: Compression-impact testing of aluminum at elevated. Exp. Mech. 3, 81 1963CrossRefGoogle Scholar
17.Lee, W.S., Lin, C.F.: Plastic deformation and fracture behavior of Ti–6Al–4V alloy loaded with high strain rate under various temperatures. Mater. Sci. Eng., A 241, 48 1998CrossRefGoogle Scholar
18.Xu, Y.B., Zhong, W.L., Chen, Y.J., Shen, L.T., Liu, Q., Bai, Y.L., Meyers, M.A.: Shear localization and recrystallization in dynamic deformation of 8090 Al–Li alloy. Mater. Sci. Eng., A 299, 287 2001CrossRefGoogle Scholar
19.Lee, W.S., Sue, W.C., Lin, C.F., Wu, C.J.: The strain rate and temperature dependence of the dynamic impact properties of 7075 Al alloy. J. Mater. Process. Technol. 100, 116 2000CrossRefGoogle Scholar
20.Conrad, H.: Thermally activated deformation of metals. J. Metal. 16, 582 1964Google Scholar
21.Shi, L., Northwood, D.O.: Mechanical behavior of an AISI type 310 stainless steel. Acta Metall. Mater. 43, 453 1995CrossRefGoogle Scholar
22.Kobayashi, H., Dood, B.: Numerical analysis for the formation of adiabatic shear bands including void nucleation and growth. Int. J. Impact Eng. 8, 1 1989CrossRefGoogle Scholar
23.Johnson, G.R., Cook, W.H.: A constitutive model and data for metals subjected to large strains, high strain rate and high temperature, in 7th International Symposium on Ballistics DYMAT, The Hague The Netherlands 1983 541Google Scholar
24.Zerilli, F.J., Armstrong, R.W.: Dislocation-mechanics-based constitutive relations for material dynamics calculations. J. Appl. Phys. 61, 1816 1987CrossRefGoogle Scholar
25.Zerilli, F.J., Armstrong, R.W.: Effect of dislocation drag on the stress-strain behavior of F.C.C. metals. Acta Metall. Mater. 40, 1803 1992CrossRefGoogle Scholar
26.Murr, L.E.: Residual microstructure-mechanical property relationships in shock-loaded metals and alloysin Shock Wave and High-Strain Rate Phenomena in Metals: Concept and Applications, edited by Meyers, M.A. Murr, L.E. Plenum Press New York 1981 Chap. 37 607Google Scholar
27.Hyland, R.W. Jr., Asta, M., Foiles, S.M., Rohrer, C.L.: Al(f.c.c.):Al3Sc(L12) interphase boundary energy calculations. Acta Mater. 46, 3667 1998CrossRefGoogle Scholar
28.Fu, C.L.: Electronic, elastic, and fracture properties of trialuminide alloys. Al3Sc and Al3Ti. J. Mater. Res. 5, 971 1990CrossRefGoogle Scholar
29.Ham, R.K.: The determination of dislocation densities in thin film. Philos. Mag. 6, 1183 1961CrossRefGoogle Scholar
30.Lee, W.S., Shyu, J.C., Chiou, S.T.: Effect of strain rate on impact response and dislocation substructure of 6061-T6 aluminum alloy. Scr. Metall. 42, 51 1999CrossRefGoogle Scholar
31.Shyu, J.C.: The effect of strain rate and temperature on the dynamic plastic deformation and dislocation substructure of 6061 Al alloy. Master Thesis, Department of Mechanical Engineering, National Cheng Kung University (Tainan, Taiwan, 1999), p. 64.Google Scholar
32.Rivas, J.M., Quinones, S.A., Murr, L.E.: Hypervelocity impact cratering: Microstructural characterization. Scr. Metall. Mater. 33, 101 1995CrossRefGoogle Scholar
33.Cuddy, J., Bassim, M.N.: Study of dislocation cell structures from uniaxial deformation of AISI 4340 steel. Mater. Sci. Eng., A 113, 421 1989CrossRefGoogle Scholar