On the nature of the second phase particles present in an as-cast Al-Cu-Mg-Ag alloy
- Defence Metallurgical Research Lab., Hyderabad (India)
Examination of phases present in the as-cast microstructure of age hardenable Al alloys has always provided important information regarding the nature of the precipitates that may form in such alloys during artificial aging. Considerable commercial interest has been shown in recent years in Al-Cu-Mg alloys containing trace addition of Ag. One of the major difficulties involved in the evaluation of the chemistry of the phase precipitates, using conventional micro analytical techniques, is their very small sizes. The difficulties experienced in providing conclusive evidence for the presence of Ag within the small rods of S precipitates formed in an Al-Cu-Mg-Ag alloy has been known in this regard. According to the ternary Al-Cu-Mg phase diagram, phases based on both {theta}(Al{sub 2}Cu) and S(Al{sub 2}CuMg) would be present (as solidification products) in the as-cast Al-Cu-Mg-Ag alloys of commercial interest. Analysis of coarse particles of S present in the as-cast Al-Cu-Mg-Ag alloys would provide decisive information regarding the presence of Ag within the S phase. In this paper, using light microscopy, scanning electron microscopy (SEM) and electron probe microanalysis (EPMA), results on the compositional analysis of the second phase particles present in an as-cast Al-Cu-Mg-Ag alloy are described. Emphasis is given on the determination of the locations of the trace alloy additions within the phase particles of interest.
- OSTI ID:
- 691325
- Journal Information:
- Scripta Materialia, Vol. 41, Issue 6; Other Information: PBD: 20 Aug 1999
- Country of Publication:
- United States
- Language:
- English
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