Authors

University of Tabriz, New materials Laboratory, Tabriz, Iran.

Abstract

Al-Cu alloys have extensive applications in the production of many industries. In this paper, the effects of both copper content and cold work amount on the microstructure and aging behavior of the alloys studied. The mechanical and microstructural parameters determined by using Vickers hardness and transmission electron microscopy, the present study is dealing with the variation of hardness and microstructure as a result of different copper contents and cold work amounts performed on Al-Cu alloys samples which has done solution heat treatment, cold worked and aged in different time intervals. The results indicate that for based samples, density and thickness of θ' precipitates increased by increasing copper concentration. Precipitation behavior of the 80% cold rolled samples was completely different from that of other samples and the nucleation of the equilibrium θ phase commenced prior to the precipitation of the metastable θ' phase. Moreover the thickness of precipitates was observed to be more than that for samples which were not cold worked. As a result, regarding the various microstructures produced by aging processes, one may choose an appropriate combination of copper content and cold work amount according to the desired application.

Keywords

  1. F.Nie and B.C.Muddle, Microstructural design of high-strength aluminum alloys, Journal of Phase Equilibria, 1998, 19 (6), 543-551
  2. W. Martin, Precipitation Hardening, First edition, Oxford, New York, Pergamon Press  1968.
  3. R. Brooks, Heat treatment, Structure and Properties of Nonferrous Alloys, 1982.
  4. R. Davis, Aluminum and Aluminum Alloys, ASM Specialty Hand book, Ohio, USA, 1993.
  5. Tatsuo Sato and Tsuneo Takahashi, Scripta Metallurgica, 1988, 22 (7) 941-946.
  6. Sankaran and C. Laird ,Scripta Metallurgica, 1977,  11(5), 383-386.
  7. Liu, G. J. Zhang, X. D. Ding, J. Sun and K. H. Chen, Materials Science and Engineering A, 2003,  344(1-2) 113-124.
  8. R. Davis, Aluminum and Aluminum Alloys, ASM Specialty Hand book, Ohio, USA, 1993.
  9. Nobuhiro Tsuji, Taku Iwata, Masahide Sato, Shinji Fujimoto and Yoritoshi, Minamino,Science and Technology of Advanced Materials, 2004,  5 (1-2), 173-180.
  10. Vaithyanathan, C.Wolverton and L. Q. Chen,ActaMaterialia, 2004, 52 (10) 2973-2987.
  11. دی. ای. پورتر، کی. ای. ایسترلینگ، استحاله فازها در فلزات و آلیاژها، ترجمه محمد رضا افضلی ، مرکز نشردانشگاهی، 1379.
  12. Dutkiewicz and L. Litynska, Materials Science and Engineering A,2002, 324)1-2(,  239-243.
  13. Novikov, Theory of heat treatment of metals, Mir Publishers,Moscow, 1974, 406-418.