Document Type



Master of Science (MS)


Materials Science and Engineering

First Advisor's Name

Arvind Agarwal

First Advisor's Committee Title

Committee chair

Second Advisor's Name

Benjamin Boesl

Second Advisor's Committee Title

Committee co-chair

Third Advisor's Name

Norma Munroe

Third Advisor's Committee Title

Committee member


ultrasonic treatment, cavitation, sonication, microstructure, hardness, dispersion, Aluminum, cast, composite

Date of Defense



In this study, the effect of ultrasonic treatment (UST) parameters such as amplitude, sonication time, and melt temperature on microstructure and microhardness of Al 6061 alloy is evaluated. The effect of UST on the dispersion of tungsten disulfide (WS2) and carbon nanotubes (CNT) as reinforcement particles in Al 6061 during casting is also studied. The cast Al 6061 with UST demonstrated 32% grain size reduction and 8% increase in the microhardness for optimum processing conditions. The cavitation process induced by UST is responsible for the refinement in microstructure and increase of hardness by enhancing the degassing and nucleation process. UST treated 6061 Al alloy demonstrated Hall-Petch relationship for all processing conditions. The UST process also aids in excellent dispersion of WS2 and CNT as reinforcement particles. UST treated WS2 and CNT reinforced Al 6061 composites displayed improved wear resistance as compared to samples without cavitation.





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