Applied Microscopy

Korean Society of Microscopy (한국현미경학회)
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A New TEM Observation of the Copper Precipitate in High Strength Al-Cu-Mg Alloy

고강도 알루미늄 합금(Al-Cu-Mg)에서 새로운 Cu 석출물의 TEM 관찰

  • 김황수 (경성대학교 이과대학 물리학과)
  • Published : 2006.06.30
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Abstract

In this paper a transmission electron microscope (TEM) observation of fine Cu precipitates distributed randomly in Al-2.5Cu-1.5Mg wt.% alloy is first reported. This new observation happened to occur when an ion milling was peformed to remove oxides on the specimen, particularly, aged 100 hours at $150^{\circ}C$. Meanwhile the oxides were identified to be $Cu_2O$ particles. For this work involved with analysis of diffraction rings, the formulation of the electron diffraction rings pattern for powder particles was made. Finally the significance of this unexpected ion milling effort on the alloy was discussed

이 논문에서 Al-2.5Cu-1.5Mg wt.% 합금에서 미세한 Cu 석출물에 대한 투과전자현미경 관찰이 보고 되었다. 이 새로운 관찰은 시료에 오염된 산화물을 제거하기 위해 ion milling을 하고 곧바로 시료 관찰을 했을 때 우연히 이루어 졌다. 특히 이 Cu석출물은 $150^{\circ}C$에서 100시간 aging한 시료에서 분명하게 관찰되었다. 그리고 ion milling 전 시료표면에서 분명히 관측되는 산화물은 $Cu_2O$임이 확실히 밝혀졌다. 이러한 분석과정은 회절 환 패턴의 정밀 분석을 요구함으로 이에 대한 시뮬레이션에 필요한 이론적 공식도 만들었다. 마지막으로 이 합금에 대한 예기치 않은 ion milling효과와 그 중요성이 논의되었다.

Keywords

References

  1. Alekseev AA, Anan'ev VN, Ber LB, Kaputkin EYa: The Structure of Strengthening Precipitates Forming in High-Temperature Aging of Al-Cu-Mg Alloys. Phys. Met. Metall. 75 : 279-285, 1993
  2. Alekseev AA, Ber LB, Klimovich LG, Korobov OS: On the Structure of the Zones in Alloy Al-Cu-Mg. Phys. Met. Metall. 46 : 80-87, 1979
  3. Alekaroff LV: Elements of X-ray Crystallography. McGraw- Hill Inc., New York 1968
  4. Charai A, Walther T, Alfonso C, Zahra AM, Zahra CY: Coexistence of Clusters, GPB Zones, $S^{\prime\prime}$-, $S^{\prime}$- and S-Phases in an Al-0.9% Cu-1.4% Mg Alloy. Acta Mater. 48 : 2751-2764, 2000 https://doi.org/10.1016/S1359-6454(99)00422-X
  5. Kilaas R, Radmilovic V: Structure Determination and Structure Refinement of $Al_2CuMg$ Precipitates by Quantitative High-Resolution Electron Microscopy. Ultramicroscopy 88 : 63-72, 2001 https://doi.org/10.1016/S0304-3991(00)00107-8
  6. Kim HS: A Study of the Crystal Structure of the Fine S-Phase Precipitate in Al-Cu-Mg Alloy by Electron Diffraction Experiments. Korean J. Electron Microscopy 35 : 187-195, 2005 (Korean)
  7. Kim HS, Ringer SP: On the Crystal Structure of the S-Phase Precipitate in Al-Cu-Mg Alloy. Microsc. Microanal. 11 (Supple 2) : 1688-1689, 2005
  8. Pearson WB: Handbook of Lattice Spacing and Structure of Metals. Oxford: Peramon press, 1964
  9. Perlitz H, Westgren A: The Crystal Structure of $Al_2CuMg$. Arkiv. Kemi. Mineral. Geol.: B16, No.13, 1-5, 1943
  10. Phillips VA: High Resolution Electron Microscope Observations on Precipitation in Al-3.0% Cu Alloy. Acta Metall., 23 : 751-767, 1975 https://doi.org/10.1016/0001-6160(75)90058-9
  11. Radmilovic V, Kilaas R, Dahmen U, Shiflet GJ: Structure and Morphology of S-Phase Precipitates in Aluminum. Acta Mater. 47 : 3987-3997, 1999 https://doi.org/10.1016/S1359-6454(99)00259-1
  12. Ringer SP, Caraher SK, Polmear IJ: Response to Comments on Cluster Hardening in an Aged Al-Cu-Mg Alloy. Scripta Mater. 39 : 1559-1567, 1998 https://doi.org/10.1016/S1359-6462(98)00364-9
  13. Ringer SP, Sakurai T, Polmear IJ: Origins of Hardening in Aged Al-Cu-Mg- (Ag) Alloys. Acta Mater. 45 : 3731-3744, 1997 https://doi.org/10.1016/S1359-6454(97)00039-6
  14. Shih HC, Ho NJ, Huang JC: Precipitation Behaviors in Al-Cu-Mg and 2024 Aluminum Alloys. Metall. Mat. Tran. A, 27A : 2479-2494, 1996
  15. Silcock JM: The Structural Aging Characteristics of Al-Cu- Mg Alloys with Copper : Magnesium Weight Ratios of 7 : 1 and 2.2 : 1. J. Inst. Met. 89 : 203-210, 1960-1961
  16. Wang SC, Starink MJ: The assessment of GPB2/$S^{\prime\prime}$ structures in Al-Cu-Mg alloys. Mater. Sci. Eng. A 386 : 156- 163, (2004) https://doi.org/10.1016/S0921-5093(04)00913-X
  17. Wolverton C: Crystal Structure and Stability of Complex Precipitate Phases in Al-Cu-Mg-(Si) and Al-Zn-Mg Alloys. Acta Mater. 49 : 3129-42, 2001 https://doi.org/10.1016/S1359-6454(01)00229-4
  18. Zahra AM, Zahra CY, Alfonso C, Charai A: Comments on 'Cluster Hardening in an Aged Al-Cu-Mg Alloy'. Scripta Mater. 39 : 1553-58, 1998 https://doi.org/10.1016/S1359-6462(98)00365-0