题目：Dispersion of Nanoparticles in Alloy Melts for Solidification Processing of Bulk Al and Mg Nanocomposites

报告人：李小春　教授

时间：5月20日（周四）下午2：30-4:00

地点：工艺楼403教室

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Dispersion of Nanoparticles in Alloy Melts for Solidification Processing of Bulk Al and Mg Nanocomposites

Xiaochun Li, Professor
Director, Nano-Engineered Materials Processing Center (NEMPC)
Department of Mechanical Engineering and Materials Science Program
University of Wisconsin-Madison
Madison, Wisconsin 53706, USA

Abstract: Light metals (e.g. Al and Mg) are of significance for automobile, aerospace and numerous other applications, where lighter vehicles/parts mean reduced use of nonrenewable fuels and lower greenhouse gas emissions. The properties of light metals can be enhanced considerably if nanoelements (e.g. nanoparticles, nano-tubes, and nano-fibers etc) are used to form nano-structured light metals or to fabricate light metal matrix nanocomposites (MMNCs). However, effective dispersion and stabilization of nanoelements in Al alloy melts is extremely challenging due to their large surface-to-volume ratio and their poor wettability, which easily induce agglomeration and clustering. High intensity ultrasonic waves can generate extremely powerful and transient cavitation effects that are promising to effectively disperse and stabilize nanoelements in liquids for nano-manufacturing/processing of bulk nano-structured Al and Mg nanocomposites. Bulk nano-sized particle reinforced aluminum and magnesium alloys were successfully fabricated. Experimental results show a nearly uniform distribution and good dispersion of nanoparticles within the metal matrix, resulting in significantly improved mechanical strength properties while maintaining or enhancing ductility. This research will enable a transformative casting technology, based on ultrasonic cavitation dispersion of nanoparticles in metal melts, for scale-up production of Al and Mg matrix nanocomposites, ultimately leading to the creation of a new metal matrix nanocomposite (MMNC) industry that will enjoy extremely wide markets.

Short Bio:

Dr. Li is a professor in the Department of Mechanical Engineering and Materials Science Program at University of Wisconsin-Madison. He received his Ph.D. in Mechanical Engineering at Stanford University in 2001. He currently serves as the founding Director of Nano-Engineered Materials Processing Center (NEMPC). Dr. Li received CAREER award from National Science Foundation (NSF) in 2002, Jiri Tlusty Outstanding Young Manufacturing Engineer Award from Society of Manufacturing Engineers in 2003, and 2008 Howard F. Taylor Award from American Foundry Society (AFS). He is the Villas Associates Scholar at University of Wisconsin-Madison. Dr. Li's research activities and interests are on the areas of Bulk Nano-structured Materials Processing and Production, Structurally Integrated Micro/Nano-Systems (SIMNS) for engineering applications, Meso/Micro-scale Rapid Manufacturing, and Laser Micro Materials Processing.