Skip to main content
SpringerLink
Log in

Metallurgical factors affecting fracture toughness of aluminum alloys

  • Published:
Metallurgical Transactions A Aims and scope Submit manuscript

Abstract

Crack extension in commercial aluminum alloys proceeds by the “ductile” or fibrous mode. The process involves the large, ~1 μm to ~10μm, Fe-, Si-, and Cu-bearing inclusions which break easily, and the growth of voids at the cracked particles. The linking-up of the voids is accomplished by the rupture of the intervening ligaments, and this is affected by the fine, ~0.01μm precipitate particles that strengthen the matrix. The ~0.1μm Cr-, Mn-, and Zr-rich intermediate particles are more resistant to cracking and may enter the process in the linking-up stage. The fracture toughness of aluminum alloys therefore depends on a) the extent of the heavily strained region ahead of the crack tip, which is a function of the yield strength arad modulus, b) the size of the ligaments which is related tof c, the volume fraction of cracked particles, and c) the work of rupturing the ligaments. An approximate analysis predicts KIc varies asf c-1/6, and this is in agreement with measurements on alloys with comparable yield strength levels. Studies in which the aging conditions are altered for the samef cshow that the toughness decreases with increasing yield strength level. This degradation in toughness is related to the localization of plastic deformation. The tendency for localization is illustrated with the help of “plane strain” tension and bend specimens whose behavior is related to the toughness. Measurements of the strain distribution on the microscale show that slip is relatively uniformly distributed in a 7000-type alloy with low inclusion and particle content when the material is in the as-quenched and overaged conditions. In contrast the distribution is highly nonuniform in the peak aged condition where slip is concentrated in widely spaced superbands involving coarse slip bands with large offsets that crack prematurely. The connection between the tendency for slip localization and the fine precipitate particles which strengthen the matrix remains to be established. In overaged alloys grain boundary ruptures occur within the superbands. The amount of intergranular failure increases with grain size and is accompanied by a loss of fracture toughness.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

References

  1. R. Develay:Metals and Materials, 1972, vol. 6, p. 404.

    Google Scholar 

  2. A. R. Rosenfield:Met. Rev., 1968, no. 121, p. 29.

  3. G. T. Hahn, M. F. Kanninen, and A. R. Rosenfield:Ann. Rev. Mater. Sci., 1972, vol. 2, p. 381.

    Article  CAS  ADS  Google Scholar 

  4. D. Broek:Eng. Fract. Mech., 1973, vol. 5, p. 55.

    Article  CAS  Google Scholar 

  5. D. Broek: Report NLR-TR-72029-u; Nat. Aerospace Lab., The Netherlands (n.d.)

  6. J. P. Tanaka, C. A. Pampillo, and J. R. Low, Jr.: ASTM-STP, 1970, vol. 463, p.191.

    Google Scholar 

  7. J. R. Low, Jr., R. H. Van Stone, and R. H. Merchant: NASA Tech. Rep. No. 2, Research Grant NCR 38-087-003, Carnegie-Mellon Univ., 1972.

  8. S. N. Singh and M. C. Flemings:Trans. AIME, 1969, vol. 245, p. 1811.

    CAS  Google Scholar 

  9. J. H. Mulherin and H. Rosenthal:Met. Trans., 1971, vol. 2, p. 427.

    Article  CAS  Google Scholar 

  10. D. S. Thompson and S. A. Levy: AFML-TR-70-171, Wright-Patterson AFB, Ohio, 1970.

  11. J. A. Nock, Jr. and H. Y. Hunsickler:J. Metals, 1963, vol. 15, p. 216.

    CAS  Google Scholar 

  12. C. J. Peel, R. N. Wilson, and P. J. E. Forsyth:Metal Sci. J., 1972, vol. 6, p. 102.

    Article  CAS  Google Scholar 

  13. P. N. T. Uhwin and G. C. Smith:J. Inst. Met., 1969, vol. 97, p. 299.

    Google Scholar 

  14. S. N. Singh and M. C. Flemings:Trans. AIME, 1969, vol. 245, p. 1803.

    CAS  Google Scholar 

  15. K. R. VanWorn, ed:.Aluminum, 1967, vol. 1, ASM, Metals Park, Ohio.

  16. L. F.Mondolfo:Met. Rev., 1971, vol. 16, p. 95.

    Google Scholar 

  17. S. M. El-Soudani and R. M. Pelloux:Met. Trans., 1973, vol. 4, p. 519.

    Article  CAS  Google Scholar 

  18. A. R. Rosenfield, C.W. Price, C.J.Martin, D. N. Williams, D.C. Drennen, D. S. Thompson, and R. E, Zinkham: Semiannual Progress Report on Con-tract F33615-71-C-1805 to AFMLJLLS, 1972.

  19. A. S. Argon, J. 1m, and R. Safoglu: Massachusetts Institute of Technology, private communication.

  20. T. B. Cox and J. R. Low, Jr.: NASA Tech. Rep. No. 3 on Research Grant NGR-39-087-003, Carnegie-Mellon Univ., 1972.

  21. J. Gurland:Acta Met., 1972, vol. 20, p. 735.

    Article  CAS  Google Scholar 

  22. T. Liu and J. Gurland:Trans. ASM, 1968, vol. 61, p. 156.

    CAS  Google Scholar 

  23. B. I. Edelson and W. M. Baldwin, Jr.:Trans. ASM, 1962, vol. 53, p. 230.

    Google Scholar 

  24. J. J. Hauser and M. G. Wells: Tech. Rep. AFML-TR-69-339, Wright Patterson AFB, Ohio, 1969.

  25. A. J. Birkle, R. P. Wei, and G. E. Pellesier:Trans. ASM, 1966, vol. 59, p. 981.

    CAS  Google Scholar 

  26. G. T. Hahn, P. N. Mincer, and A. R. Rosenfield:Exp. Mech., 1971, vol. 11, p. 248.

    Article  Google Scholar 

  27. J. R. Rice and M. A. Johnson:Inelastic Behavior of Solids, M. F. Kanninen, et al., eds., p.641, McGraw-Hill, New York, 1970.

    Google Scholar 

  28. J. W. Hutchinson:J. Mech. Phys. Solids, 1968, vol. 16, p. 13.

    Article  MATH  ADS  Google Scholar 

  29. N. Levy, P. V. Marcal, W. J. Ostergren, and J. R. Rice:Int. J. Fract. Mech., 1971, vol.7, p. 143.

    Google Scholar 

  30. F. A. McClintock:Fracture, H. Liebowitz, ed., vol. 3, p. 106, Academic Press, New York, 1971.

    Google Scholar 

  31. J. R. Rice and D. M. Tracey:J. Mech. Phys. Solids, 1969, vol. 17, p. 201.

    Article  ADS  Google Scholar 

  32. J.M. Krafft:Appl. Mater. Res., 1964, vol. 3, p. 88.

    Google Scholar 

  33. F. A. McClintock:Fracture, H. Liebowitz, ed., vol. 3, p. 47, Academic Press, New York, 1971.

    Google Scholar 

  34. P. F. Thomasson:Int. J. Fract. Mech., 1971, vol. 7, p. 409.

    Google Scholar 

  35. G. T. Hahn and A. R. Rosenfield: Paper PL-III-211, Third Int. Conf. Fracture, Munich, 1973.

  36. T. B. Cox and J. R. Low, Jr.: NASA Tech. Rep. No. 4 on Research Grant NGR-39-087-003, Carnegie-Mellon Univ., 1972.

  37. F. A. McClintock, S. M. Kaplan, and C. A. Berg:Int. J. Fract. Mech., 1966, vol. 2, p. 615.

    Google Scholar 

  38. C. A. Berg:Inelastic Behavior of Solids, M.F. Kanninen,et al, eds., p. 171, McGraw-Hill, New York, 1970.

    Google Scholar 

  39. C. A. Griffis and J. W. Spretnak:J Iron Steel Inst. Japan, 1969, vol. 9, p. 372.

    Google Scholar 

  40. M. S. Hunter and J. C. McMillan: ASTM-STP, 1968, vol. 436, p. 196.

    Google Scholar 

  41. A. Kelly and R. B. Nicholson:Prog. Mater. Sci, 1963, vol. 10, p. 151.

    Article  Google Scholar 

  42. J. D. Embury and R. B. Nicholson:Acta Met, 1965, vol. 13, p. 403.

    Article  CAS  Google Scholar 

  43. M. O. Speidel:Fundamental Aspects of Stress Corrosion Cracking, p. 561, Nat. Assn. Corr. Engs., Houston, 1969.

  44. R. N. Wilson and P. G. Partridge:Acta Met., 1965, vol. 13, p. 1321.

    Article  CAS  Google Scholar 

  45. R. N. Wilson, D. M. Moore, and P. J. E. Forsythe:J. Inst. Metals, 1967, vol. 95, p. 177.

    CAS  Google Scholar 

  46. N. Sen and D. R. F. West:The Mechanism of Phase Transformations in Crystalline Solids, p. 49, Inst. Met., London, 1969.

    Google Scholar 

  47. R. E. Zinkham, J. H. Dedrick, and J. H. Jackons: Proceedings of 5th International Leichtmetalltagung Leoben Austria, 1968, Aluminium-Verlag GMBH, Dusseldorf, Germany.

    Google Scholar 

  48. T. M. F. Ronald and D. P. Voss: Metals and Ceramics Synthesis Branch, LLS, Wright-Patterson AFB, Ohio, unpublished research.

  49. D. P. Clausing:Int. J. Fract. Mech., 1970, vol. 6, p. 71.

    Google Scholar 

  50. D. P. Clausing: Tech. Rep. on Project No. 35.066-001(2), U.S. Steel Corp., Research Lab., 1972.

  51. S. A. Mohamed and A. S. Tetelman: Proceedings of the Third Int. Conf. on Fracture, Vol. III, Verein Deutscher Eisenhuttenleute, Dusseldorf, Germany, April, 1973, Paper II-511.

    Google Scholar 

  52. D. L. McGarry: M.S. Thesis, Ohio State University, 1972.

  53. A. S. Tetelman: Univ. of Cal. at L. A., private communication, 1973.

  54. V. Weiss and N. Sengupta: Proceedings of the Third Int. Conf. on Fracture, Vol. IV, Verein Deutscher Eisenhuttenleute, Dusseldorf, Germany, April, 1973, Paper III-341.000

    Google Scholar 

  55. J. D. Boyd, D. S. Thompson, D. N. Williams, and D. C. Drennen: First Semi- annual Progress Report on Contract F33615-71-C1805 to AFMLJLLS, January 31, 1972.

  56. I. Kirman:Met. Trans., 1971, vol. 2, p. 1761.

    CAS  Google Scholar 

  57. D. S.Thompson, R. E. Zinkham, and C. W. Price: unpublished research on Contract No. F33615-71-C-1805.

  58. C. J. Beevers and W. K. Honeycomb:Phil. Mag., 1962, vol. 7, p. 763.

    Article  CAS  ADS  Google Scholar 

  59. R. J. Price and A. Kelly:Acta Met., 1964, vol. 2, p. 979.

    Article  Google Scholar 

  60. D. Harkness and J.J. Hren:Met. Trans., 1970, vol. 1, p. 43.

    CAS  Google Scholar 

  61. I. G. Palmer and G. C. Smith:Oxide Dispersion Strengthening, p. 253, Gordon and Breach, 1968.

  62. G. T. Hahn and A. R. Rosenfield: unpublished research.

  63. T. B. Cox and J. R. Low, Jr.: NASA Technical Report No. 5, Dept. of Metallurgy and Materials Science, Carnegie-Mellon Univ., 1973.

Download references

Author information

Authors and Affiliations

  1. Metal Science Section, Battelle, Columbus Laboratories, 43201, Columbus, Ohio

    G. T. Hahn (Manager) & A. R. Rosenfield (Associate Manager)

Authors
  1. G. T. Hahn
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. A. R. Rosenfield
    View author publications

    You can also search for this author in PubMed Google Scholar

Additional information

This paper is based on an invited presentation made at a symposium on “Advances in the Physical Metallurgy of Aluminum Alloys” held at the Spring Meetings of TMS-IMD in Philadelphia, Pennsylvania, on May 29 to June 1, 1973. The symposium was co-sponsored by the Physical Metallurgy Committee and the Non-Ferrous Metals Committee of TMS-IMD

Rights and permissions

Reprints and permissions

About this article

Cite this article

Hahn, G.T., Rosenfield, A.R. Metallurgical factors affecting fracture toughness of aluminum alloys. Metall Trans A 6, 653–668 (1975). https://doi.org/10.1007/BF02672285

Download citation

  • Issue Date:

  • DOI: https://doi.org/10.1007/BF02672285

Keywords

Search

Navigation