Title page for ETD etd-05212003-205819


Type of Document Master's Thesis
Author Goff, Adam Carter
Author's Email Address agoff@vt.edu
URN etd-05212003-205819
Title Modeling and Synthesis of a Piezoelectric Ceramic-Reinforced Metal Matrix Composite
Degree Master of Science
Department Materials Science and Engineering
Advisory Committee
Advisor Name Title
Kampe, Stephen L. Committee Chair
Aning, Alexander O. Committee Member
Corcoran, Sean Gerald Committee Member
Keywords
  • Eshelby Method
  • Metal Matrix Composites
  • Piezoelectricity
  • Mechanical Damping
Date of Defense 2003-05-15
Availability unrestricted
Abstract
A mathematical model has been created based on J.D. Eshelby’s equivalent inclusion method that can predict the elastic modulus and damping capability in the form of Joule heat for any piezoelectric ceramic-reinforced metal matrix composite system. Specifically, barium titanate (BaTiO3), lead titanate (PbTiO3), and zinc oxide (ZnO) piezoelectric ceramics have been modeled as dispersed particles shaped as spheres, prolate spheroids, and discs within a host of common structural metallic matrices including 304 stainless steel, mild steel, aluminum, brass, copper, lead, magnesium, nickel, Ni-20wt%Cr, tin, titanium, Ti-6Al-4V(at%), and tungsten. Composite systems that were predicted to exhibit the greatest level of damping capacity include copper, aluminum, and magnesium matrices reinforced with PbTiO3, BaTiO3, and ZnO, in descending order of damping magnitude. In general, higher-conducting, lower-stiffness metallic matrices coupled with more-piezoelectric, higher-stiffness ceramic reinforcement resulted in the greatest level of predicted damping capability and enhanced composite elastic modulus. Additionally, a Ni-20wt%Cr-30v%BaTiO3 composite has been created using mechanical alloying processing. Specifically, pure constituent powders were combined stoichiometrically in a SPEX milling vial utilizing a charge ratio of 4:1 and subsequently milled for 24 hours. Separate composite powder samples were then annealed in a hydrogen tube furnace at 400°C, 500°C, and 600°C for one and five hours at each temperature. X-ray diffraction was performed on the as-milled and the annealed powders revealing that each was composed of the starting constituents in the appropriate proportions. Representative powders were mounted and polished using common metallographic procedures and microstructures were examined by optical microscopy, scanning electron microscopy, and transmission electron microscopy. All of the powders exhibited a good dispersion of BaTiO3 particles ranging in diameter from 1ìm to about 25nm with no noticeable difference between the as-milled and the annealed powders.
Files
  Filename       Size       Approximate Download Time (Hours:Minutes:Seconds) 
 
 28.8 Modem   56K Modem   ISDN (64 Kb)   ISDN (128 Kb)   Higher-speed Access 
  finalthesis.pdf 4.65 Mb 00:21:31 00:11:04 00:09:41 00:04:50 00:00:24

Browse All Available ETDs by ( Author | Department )

dla home
etds imagebase journals news ereserve special collections
virgnia tech home contact dla university libraries

If you have questions or technical problems, please Contact DLA.