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Effect of precipitate volume fraction on fracture toughness of extruded Mg–Zn alloys

Published online by Cambridge University Press:  31 January 2011

Hidetoshi Somekawa ,
Yoshiaki Osawa ,
Alok Singh  and
Toshiji Mukai
Hidetoshi Somekawa*
Affiliation:
Structural Metals Center, National Institute for Materials Science, Tsukuba, Ibaraki 305-0047, Japan
Yoshiaki Osawa
Affiliation:
Structural Metals Center, National Institute for Materials Science, Tsukuba, Ibaraki 305-0047, Japan
Alok Singh
Affiliation:
Structural Metals Center, National Institute for Materials Science, Tsukuba, Ibaraki 305-0047, Japan
Toshiji Mukai
Affiliation:
Structural Metals Center, National Institute for Materials Science, Tsukuba, Ibaraki 305-0047, Japan
*
a)Address all correspondence to this author. e-mail: [email protected]
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Abstract

Four kinds of extruded Mg–X at.% Zn binary alloys (X = 1.9, 2.4, 3.0, and 3.4) were used to examine the effect of precipitate volume fraction on fracture toughness. All the alloys had fine grain sizes of 1–3 μm and fine sphere-shaped precipitates of 50–60 nm. The volume fraction of precipitates increased with additional zinc content. The results of mechanical property tests showed that the extruded Mg–2.4 at.% Zn alloy exhibited the best balance of strength and fracture toughness. One of the reasons was the different volume fraction of precipitates at the grain boundaries, which was the source of void formation. According to the fracture surface observations and ductile fracture model analysis, the volume fraction of precipitates of 2%–4% was shown to be enough to improve the fracture toughness for the fine-grained magnesium alloys; i.e., higher contents of zinc atoms were not needed to enhance the mechanical properties.

Keywords

ToughnessMg
Type
Articles
Information
Journal of Materials Research , Volume 23 , Issue 4 , April 2008 , pp. 1128 - 1135
Copyright
Copyright © Materials Research Society 2008

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References

REFERENCES

1Barbagallo, S.Cerri, E.: Evaluation of the K IC and J IC fracture parameters in a sand AZ91 magnesium alloy. Eng. Fail. Anal. 11, 127 2004Google Scholar
2Lee, S., Lee, S.H.Kim, D.H.: Effect of Y, Sr, and Nd additions on the microstructure mechanism of squeeze-cast AZ91-X magnesium alloys. Metall. Mater. Trans. A 29, 1221 1998CrossRefGoogle Scholar
3Purazrang, K., Kainer, K.U.Mordike, B.L.: Fracture toughness behavior of a magnesium alloy metal-matrix composite produced by the infiltration technique. Composite 22, 456 1991CrossRefGoogle Scholar
4Sasaki, T., Somekawa, H., Takara, A., Nishikawa, Y.Higashi, K.: Plane-strain fracture toughness on thin AZ31 wrought magnesium alloy sheets. Mater. Trans. 44, 986 2003CrossRefGoogle Scholar
5Somekawa, H.Mukai, T.: Effect of grain refinement on fracture toughness in extruded pure-magnesium. Scripta Mater. 53, 1059 2005Google Scholar
6Somekawa, H., Singh, A.Mukai, T.: High fracture toughness of extruded Mg–Zn–Y alloy by the synergetic effect of grain refinement and dispersion of quasicrystalline phase. Scripta Mater. 56, 1091 2007Google Scholar
7Somekawa, H.Mukai, T.: Fracture toughness in Mg–Al–Zn alloy processed by equal-channel-angular extrusion. Scripta Mater. 54, 633 2006Google Scholar
8Somekawa, H.Mukai, T.: Fracture toughness in ultra fine-grained magnesium alloy. Mater. Sci. Forum 503–504, 155 2006Google Scholar
9Yoshinaga, H.Horiuchi, R.: Deformation mechanisms in magnesium single crystals compressed in the direction parallel to hexagonal axis. Mater. Trans., JIM 4, 1 1963CrossRefGoogle Scholar
10Meyers, M.A., Vohringer, O.Lubarda, V.A.: Then onset of twinning in metals: A constitutive description. Acta Mater. 49, 4025 2001CrossRefGoogle Scholar
11Koike, J., Kobayashi, T., Mukai, T., Watanabe, H., Suzuki, M., Maruyama, K.Higashi, K.: The activity of non-basal slip system and dynamic recovery at room temperature in fine-grained AZ31B magnesium alloys. Acta Mater. 51, 2055 2003CrossRefGoogle Scholar
12Koike, J., Ohyama, R., Kobayashi, T., Suzuki, M.Maruyama, K.: Grain-boundary sliding in AZ31 magnesium alloys at room temperature to 523 K. Mater. Trans. 44, 445 2003CrossRefGoogle Scholar
13Somekawa, H., Singh, A.Mukai, T.: Deformation structure after fracture toughness test of Mg–Al–Zn alloys processed by equal-channel-angular extrusion. Philos. Mag. Lett. 86, 195 2006CrossRefGoogle Scholar
14Somekawa, H., Singh, A.Mukai, T.: Synergetic effect of grain refinement and spherical shaped precipitate dispersions in fracture toughness of a Mg–Zn–Zr alloy. Mater. Trans. 48, 1422 2007CrossRefGoogle Scholar
15Somekawa, H., Kim, H.S., Singh, A.Mukai, T.: Fracture toughness in direct extruded Mg–Al–Zn alloys. J. Mater. Res. 22, 2598 2007Google Scholar
16Nie, J.F.: Effects of precipitate shapes and orientation on dispersion strengthening in magnesium alloys. Scripta Mater. 48, 1009 2003Google Scholar
17Somekawa, H.Mukai, T.: Fracture toughness in an extruded ZK60 magnesium alloy. Mater. Trans. 47, 995 2006Google Scholar
18Somekawa, H.Mukai, T.: High strength and fracture toughness balance on the extruded Mg–Ca–Zn alloy. Mater. Sci. Eng., A 459, 366 2007CrossRefGoogle Scholar
19Somekawa, H., Singh, A.Mukai, T.: Effect of precipitate shapes on fracture toughness in extruded Mg–Zn–Zr magnesium alloys. J. Mater. Res. 22, 965 2007Google Scholar
20Aluminum and Aluminum Alloys, A.S.M. Specialty Handbook, edited by J.R. Davis ASM International Materials Park, OH 1993 645–705Google Scholar
21ASTM E399 Standard Test Method for Plane-Strain Fracture Toughness of Metallic Materials American Society for Testing and Materials West Conshohocken, PA 2001Google Scholar
22ASTM E399 Standard Test Method for Measurement of Fracture Toughness American Society for Testing and Materials West Conshohocken, PA 2001Google Scholar
23Somekawa, H.Mukai, T.: Effect of texture on fracture toughness in extruded AZ31 magnesium alloy. Scripta Mater. 53, 541 2005Google Scholar
24Spizing, W.A.: Electron microfractography. ASTM STP 453, 90 1969Google Scholar
25Massalski, T.B.Binary Alloy Phase Diagrams, 2nd ed.ASM International Materials Park, OH 1990 2571Google Scholar
26Clark, J.B.: Transmission-electron-microscopy study of age hardening in a Mg–5 wt% Zn alloy. Acta Mater. 13, 1281 1965Google Scholar
27Lapovok, R., Cottam, R., Thomson, P.Estrin, Y.: Extraordinary superplastic ductility of magnesium alloy ZK60. J. Mater. Res. 20, 1375 2005CrossRefGoogle Scholar
28Watanabe, H., Moriwaki, K., Mukai, T., Ohsuna, T., Hiraga, K.Higashi, K.: Materials processing for structural stability in a ZK60 magnesium alloy. Mater. Trans. 43, 775 2003Google Scholar
29Morozumi, S.: Metals Handbook Japan Institute of Metals Tokyo, Japan 1990 940Google Scholar
30DeHoff, R.T.Rhines, F.N.: Quantitative Microscopy McGraw-Hill New York 1968Google Scholar
31Cahn, J.W.Nutting, J.: Transmission quantitative metallography. Trans. ASME 215, 526 1959Google Scholar
32Somekawa, H., Osawa, Y.Mukai, T.: Effect of solid-solution strengthening on fracture toughness in extruded Mg–Zn alloys. Scripta Mater. 55, 593 2006Google Scholar
33Walls, A.A.: Unstable crack propagation in metals: Cleavage and fast fracture, in Crack Propagation Symposium Proceedings, Vol. 1, Cranfield College of Aeronautics UK 1961 210Google Scholar
34Higashi, K., Ohnishi, T., Komatsu, K.Nakatani, Y.: Evaluation of fracture toughness of 5083 and 7075 alloys by stretched zone analysis. J. Jpn. Inst. Light. Metals 31, 720 1981Google Scholar
35Magnesium and Magnesium Alloys, A.S.M. Specialty Handbook edited by M.M. Avedesian and H. Backer ASM International Materials Park, OH 1999 258–273Google Scholar
36Ritchie, P.O.Thompson, A.W.: On macroscopic and microscopic analysis for crack initiation and crack growth toughness in ductile alloys. Metall. Mater. Trans. A 16, 233 1985Google Scholar
37Rice, J.R.Rosengren, G.F.: Plane strain deformation near a crack tip in a power-law hardening material. J. Mech. Phys. Solids 16, 1 1968CrossRefGoogle Scholar
38Hutchison, J.W.: Single behavior at the end of a tensile crack in a hardening material. J. Mech. Phys. Solids 16, 13 1968Google Scholar
39Shih, C.F.: Fracture analysis. ASTM STP 560, 187 1974Google Scholar
40Thompson, A.W.Ashby, M.F.: Fracture surface micro-roughness. Scripta Metall. Mater. 18, 127 1984CrossRefGoogle Scholar
41Thompson, A.W.: The relation between changes in ductility and in ductile fracture topography-control by microvoid nucleation. Acta Metall. Mater. 31, 1517 1983CrossRefGoogle Scholar
42Kobayashi, T., Niinomi, M.Adachi, M.: Effects of triaxiality and microstructure on the ductile fracture morphology of Al–Zn– Mg–Cu–Zr alloys. J. Jpn. Inst. Metals 52, 26 1988CrossRefGoogle Scholar
43Ludtka, G.M.Laughlin, D.E.: The influence of microstructure and strength on the fracture mode and toughness of 7XXX series aluminum alloys. Metall. Mater. Trans. A 13, 411 1982CrossRefGoogle Scholar
44Hahn, G.T.Rosenfield, A.R.: Metallurgical factors affecting fracture toughness of aluminum alloys. Metall. Mater. Trans. A 6, 653 1975CrossRefGoogle Scholar