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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Thermal analysis during solidification of an Al-Cu eutectic alloy: interrelation of thermal parameters, microstructure and hardness

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Author(s):
Kakitani, Rafael [1] ; de Gouveia, Guilherme Lisboa [2] ; Garcia, Amauri [1] ; Cheung, Noe [1] ; Spinelli, Jose E. [2]
Total Authors: 5
Affiliation:
[1] Univ Estadual Campinas, UNICAMP, Dept Mfg & Mat Engn, BR-13083860 Campinas, SP - Brazil
[2] Univ Fed Sao Carlos, Dept Mat Engn, BR-13565905 Sao Carlos, SP - Brazil
Total Affiliations: 2
Document type: Journal article
Source: JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY; v. 137, n. 3, p. 983-996, AUG 2019.
Web of Science Citations: 1
Abstract

Eutectic alloys are considered promising candidates for high-temperature structural applications. In spite of this, quantitative examination of the effect of the length scale of the eutectic microstructure on mechanical properties remains a challenge. In this sense, assessments of morphology, size and distribution of the phases forming the eutectic mixture, solidified under transient regime and different cooling conditions, endure necessary. In the present study, a large spectrum of cooling rates has been obtained during unsteady-state directional solidification of an Al-33mass% Cu alloy. The main techniques utilized were: optical microscopy; scanning electron microscopy with X-ray energy-dispersive spectroscopy, X-ray fluorescence spectroscopy and Vickers hardness (HV). The resulting microstructures related to various solidification cooling rates are shown to be formed by eutectic colonies. Three microstructural zones constitute the colony, that is, a fine central regular lamellar Al-Al2Cu eutectic, an intermediate narrow wavy lamellar eutectic and a coarse boundary eutectic zone. Iron impurity appears to be able to degenerate the eutectic into a more randomly distributed microstructure. The colonies' morphology exhibits a transition from regular to platelike cells with the increase in cooling rate. Furthermore, the evolution of hardness as a function of the colony spacings is outlined. The highest hardness of 200 HV is related to an ultrafine bimodal structure formed by platelike eutectic colonies with 13 mu m in spacing with very fine lamellae of 330nm in spacing. (AU)

FAPESP's process: 17/12741-6 - Application of experimental solidification techniques, characterization of microstructure and properties in the evaluation of eutectic and hypereutectic Al-base and Zn-base alloys
Grantee:José Eduardo Spinelli
Support Opportunities: Regular Research Grants