New investigation of phase equilibria in the system Al-Cu-Si
| Autor: | Norbert Ponweiser, Klaus W. Richter |
|---|---|
| Rok vydání: | 2011 |
| Předmět: |
Materials science
Mechanical Engineering Metals and Alloys Thermodynamics Ternary phase diagram Isothermal process Article Aluminum alloys law.invention chemistry.chemical_compound Crystallography Copper alloys chemistry Optical microscope Ternary compound law Mechanics of Materials Differential thermal analysis Materials Chemistry Solubility Ternary operation Al–Cu–Si system Phase diagram Solid solution |
| Zdroj: | Journal of Alloys and Compounds |
| ISSN: | 0925-8388 |
| Popis: | Highlights ► Isothermal sections at 500 and 700 °C investigated. ► Vertical sections (partial at 10 at.% Si, complete at 40 at.% Si) determined. ► Partial ternary reaction scheme (Scheil diagram) established. ► New ternary compound identified. The phase equilibria and invariant reactions in the system Al–Cu–Si were investigated by a combination of optical microscopy, powder X-ray diffraction (XRD), differential thermal analysis (DTA) and electron probe micro analysis (EPMA). Isothermal phase equilibria were investigated within two isothermal sections. The isothermal section at 500 °C covers the whole ternary composition range and largely confirms the findings of previous phase diagram investigations. The isothermal section at 700 °C describes phase equilibria only in the complex Cu-rich part of the phase diagram. A new ternary compound τ was found in the region between (Al,Cu)-γ1 and (Cu,Si)-γ and its solubility range was determined. The solubility of Al in κ-CuSi was found to be extremely high at 700 °C. In contrast, no ternary solubility in the β-phase of Cu–Al was found, although this phase is supposed to form a complete solid solution according to previous phase diagram assessments. Two isopleths, at 10 and 40 at.% Si, were investigated by means of DTA and a partial ternary reaction scheme (Scheil diagram) was constructed, based on the current work and the latest findings in the binary systems Al–Cu and Cu–Si. The current study shows that the high temperature equilibria in the Cu-rich corner are still poorly understood and additional studies in this area would be favorable. |
| Databáze: | OpenAIRE |
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