STUDY OF MACROSEGREGATION EFFECTS ON THERMAL AND ELECTRICAL CHARACTERISTICS OF ALUMINUM-COPPER ALLOY
No Thumbnail Available
Files
Date
2018
Authors
Obiekea, V.D.
Sekunowo, I.O.
Sobamowo, M.G.
Adeosun, S.O.
Journal Title
Journal ISSN
Volume Title
Publisher
ACTA TECHNICA CORVINIENSIS – Bulletin of Engineering
Abstract
Macrosegregation phenomenon regardless of casting size often induces high partition coefficient (k) impacting
adversely the thermal and electrical properties of cast binary alloy. In this study, an experimental investigation of macrosegregation
propagation in aluminum-copper alloy solidification is reported. Al6wt. % Cu was produced at varied pouring heights including
100 mm, 200 mm, 300 mm, 400 mm and 500 mm. The combinations of optical, scanning electron and energy dispersive
spectrometry were used to evaluate the extent of segregation in the casts while the electrical and thermal conductivity properties
were determined using Wiedemann-Franz Law. Results show that the Al-Cu cast at a pouring height of 400 mm demonstrated the
highest electrical and thermal conductivity of 55 %IACS and 2.1437 W/mK 10-6 respectively. This compared well with established
standard values in application such as heat exchangers and electronic sensors. The occurrence of minimal macrosegregation at
400 mm pouring height may be attributed to appropriateness of melt-flow regime resulting in desirable microstructure that
prevents long-range solute/solvent segregation.
Description
Keywords
macrosegregation, Al-Cu alloy, electrical conductivity, thermal conductivity
Citation
Obiekea, V.D. Sekunowo, I.O. Sobamowo, M.G. Adeosun, S.O. (2018). STUDY OF MACROSEGREGATION EFFECTS ON THERMAL AND ELECTRICAL CHARACTERISTICS OF ALUMINUM-COPPER ALLOY. ACTA TECHNICA CORVINIENSIS – Bulletin of Engineering Tome XI: 35-38