Title: Electrical resistivity measurements of Al-cast alloys during solidification

Authors: Mitja Petrič; Jožef Medved; Sebastjan Kastelic; Primož Mrvar

Addresses: Faculty of Natural Sciences and Engineering, Aškerčeva c. 12, 1000 Ljubljana, Slovenia ' Faculty of Natural Sciences and Engineering, Aškerčeva c. 12, 1000 Ljubljana, Slovenia ' Faculty of Natural Sciences and Engineering, Aškerčeva c. 12, 1000 Ljubljana, Slovenia ' Faculty of Natural Sciences and Engineering, Aškerčeva c. 12, 1000 Ljubljana, Slovenia

Abstract: The aim of this paper was the selection of proper electrodes material regarding four-probe technique for the electrical resistivity measurements of Al-Si cast alloys. The most significant problem for electrodes is oxidation during measurements causing high contact resistance and providing incorrect results. Various materials were tested and aluminium electrodes chosen. The advantage of aluminium electrodes is that they melt within the specimen immediately after being poured and cause no interface resulting with any contact resistance. Pure aluminium and eutectic AlSi12 alloys were tested. Resistivity of Al-Si alloys is increasing with Si content. Grain refinement and modification of β_Si were employed. Grain refinement has any effect on electrical resistivity. Modification of β_Si phase causes decrease of electrical resistivity.

Keywords: electrical resistivity; electrode materials; aluminium alloys; grain refinement; modification; cast alloys; solidification; silicon; aluminium electrodes.

DOI: 10.1504/IJMMP.2015.068315

International Journal of Microstructure and Materials Properties, 2015 Vol.10 No.1, pp.64 - 73

Published online: 29 Mar 2015 *

Full-text access for editors Full-text access for subscribers Purchase this article Comment on this article