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Experimental-numerical study of AA5754 microstructural evolution under electromagnetic ultrasonic merged fields

Haghayeghi, R ; Sharif University of Technology | 2015

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  1. Type of Document: Article
  2. DOI: 10.1016/j.jmatprotec.2015.05.029
  3. Publisher: Elsevier Ltd , 2015
  4. Abstract:
  5. The effect of combined electromagnetic-ultrasonic fields evaluated on grain refinement. Cavitation induced by the combination of technologies suggested as major mechanism for grain refinement. A numerical simulation performed predicting the cavitation regions in the molten AA5754 aluminum alloy. It was concluded that the cavitation phenomenon occurs near the electromagnetic and ultrasonic sources. The observed acoustic streaming induced by ultrasonic horn is more intensive than the electromagnetic one. The ultrasonic streaming could transport small bubbles into the bulk rapidly. These micro-bubbles collapsed due to acoustic vibrations where the resulting micro-jets were strong enough to break the oxide layer, wetting impurities. Exogenous particles, intermetallic and oxides may contribute to the formation of fine, uniform and equiaxed microstructure across the treated melt. Experimental results confirmed the simulation predictions
  6. Keywords:
  7. Ultrasonic ; Cavitation ; Grain size and shape ; Solidification ; Ultrasonics ; Acoustic vibration ; Cavitation phenomenon ; Electromagnetic ; Equiaxed microstructures ; Simulation ; Simulation prediction ; Ultrasonic field ; Ultrasonic sources ; Grain refinement
  8. Source: Journal of Materials Processing Technology ; Volume 225 , 2015 , Pages 103-109 ; 09240136 (ISSN)
  9. URL: http://www.sciencedirect.com/science/article/pii/S0924013615300091