MATERIALS SCIENCE AND ENGINEERING SEMINAR MSE PhD Examination Part I Dynamic Recrystallization Behavior of Particulate Reinforced Metal Matrix Composite during Secondary Processing by: Yiwei Sun Co-Advisors: Prof. K. Trumble & Prof. D. Johnson ABSTRACT Particulate reinforced metal matrix composites (MMC) have been recognized to have enhanced mechanical properties compared with their monolithic counterparts and consists the largest quantity of MMCs currently being used. Secondary processing, in forms of extrusion, rolling or forging, is frequently adopted after primary fabrication of these MMCs for purposes of shape forming and property improvement. During the process, the particulate reinforcements play an important role in the microstructural evolution and greatly influence the mechanical properties of the final product. Particle re-distribution and particle cracking have been observed during secondary processing. In addition, the existence of the hard ceramic particles in the relatively soft metal matrix leads to heterogeneity in strain during deformation and the deformation zones in the vicinity of particles (PDZ) give rise to particle stimulated nucleation (PSN) of recrystallized grains, which is the subject of this document. Date: Monday, October 6, 2014 Time: 10:30 AM Place: ARMS 1028 Lisa Stacey Secretary/Development Assistant Purdue University School of Materials Engineering 765/494-4100