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Grain refinement of AA5754 aluminum alloy by ultrasonic cavitation: Experimental study and numerical simulation

Haghayeghi, R ; Sharif University of Technology | 2015

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  1. Type of Document: Article
  2. DOI: 10.1007/s12540-014-6015-5
  3. Publisher: Korean Institute of Metals and Materials , 2015
  4. Abstract:
  5. In this work, an experimental investigation was carried out on the grain refinement of molten AA5754 Aluminum alloy through ultrasonic treatment. The cavitation induced heterogeneous nucleation was suggested as the major mechanism for grain refinement in the AA5754 aluminum alloy. A numerical simulation was performed to predict the formation, growth and collapse of cavitation bubbles in the molten AA5754 Aluminum alloy. Moreover, the acoustic pressure distribution and the induced acoustic streaming by ultrasonic horn reactor were investigated. It is suggested that the streaming by ultrasonic could transport the small bubbles formed in the ultrasonic cavitation zone into the bulk of melt rapidly. These micro-bubbles are collapsed due to acoustic vibrations where the resulting micro-jets are strong enough to break the oxide layer and to wet the impurities. These exogenous particles, intermetallics and oxides could contribute to the formation of fine, uniform and equiaxed microstructure across the treated melt. The experimental results confirmed the simulation predictions
  6. Keywords:
  7. Grain refinement ; Liquid ; Nucleation ; Solidification ; Ultrasonic
  8. Source: Metals and Materials International ; Volume 21, Issue 1 , 2015 , Pages 109-117 ; 15989623 (ISSN)
  9. URL: http://link.springer.com/article/10.1007/s12540-014-6015-5