Paper Title:
Nucleation with Collapse of Acoustic Cavitation in Molten Al-Si Alloys
  Abstract

Ultrasonic irradiation during the solidification of molten metals has an effect on grain refinement. However, the mechanism of grain refinement by ultrasonic vibration has not been fully understood yet, so that there exist difficulties to apply the ultrasonic grain refinement to industrial casting processes. In the present study, we propose the mechanism of ultrasonic grain refinement: the nucleation is based on the extremely high pressure generated by the collapse of acoustic cavitation in molten Al-Si alloys. The effect of ultrasonic irradiation into molten Al-Si alloy on the microstructure was firstly studied, that is, molten Al-12.6wt%Si alloy was rapidly cooled down from just above the eutectic temperature after the ultrasonic irradiation. The detailed microstructure observation exhibits that ultrasonic irradiation above the eutectic temperature causes crystalline -Al and silicon to nucleate. Through the measurement of silicon content in -Al nodules solidified with ultrasonic irradiation, the silicon content is higher than that in non-irradiated -Al nodules. It is known that the collapse of acoustic cavitation generates extremely high pressure. At the highly pressurized sites, the eutectic temperature rises and the crystallized -Al nodules contain higher amount of silicon compared with those solidified at ambient pressure. According to the fact that the -Al nodules crystallized above the eutectic temperature contain higher amount of silicon, the irradiated microstructure of -Al nodules is developed at the highly pressurized sites, that is, the collapse of acoustic cavitation induces nucleation and causes grain refinement.

  Info
Periodical
Advanced Materials Research (Volumes 89-91)
Edited by
T. Chandra, N. Wanderka, W. Reimers , M. Ionescu
Pages
190-195
DOI
10.4028/www.scientific.net/AMR.89-91.190
Citation
Y. Fukui, Y. Tsunekawa, M. Okumiya, "Nucleation with Collapse of Acoustic Cavitation in Molten Al-Si Alloys", Advanced Materials Research, Vols. 89-91, pp. 190-195, 2010
Online since
January 2010
Export
Price
$32.00
Share

In order to see related information, you need to Login.

In order to see related information, you need to Login.

Authors: Petru Moldovan, Gabriela Popescu, Marilena Cuhutencu
Abstract:The aim of the paper is to present the influence of a new multifunctional material, a master alloy named Al-Sr-Ti-B, in aluminum foundry...
223
Authors: Ai Qin Wang, Jing Pei Xie, Zhong Xia Liu, Ji Wen Li, Wen Yan Wang, Shu Qing Yan
Abstract:In the present work, rapidly solidified alloys strips with Al-0.24Ti and Al-21Si-0.24Ti(in wt.%) were prepared by single roller...
27
Authors: Arne K. Dahle
Abstract:The nucleation dynamics and grain refinement during solidification are reviewed. Control of the nucleation of phases is an essential step in...
287
Authors: Wei Ke An, An Hui Cai, Xiang Fu Tan, Xiao Song Li, Yun Luo
Chapter 1: Applied Mechanics and Materials
Abstract:The Al-40Si alloy modified by 1.0 wt% Sr addition was heat-treated using L9(34) orthogonal test. The mechanical properties were measured. The...
108
Authors: S.P. Nikanorov, B.K. Kardashev, B.N. Korchunov, V.N. Osipov
Chapter 4: Dislocation Dynamics
Abstract:Acoustic measurements of Young’s modulus and internal friction at frequencies of longitudinal vibrations of about 100 kHz were made in the...
161