Date of Award
2007
Degree Type
Thesis
Degree Name
Master of Engineering Science
Program
Mechanical and Materials Engineering
Supervisor
Robert J. Klassen
Abstract
Constant force nanoindentation creep tests were performed on 2024 aluminum to assess the dependence of the indentation creep rate upon indentation depth h, crystal orientation, distance L to a grain boundary and grain boundary misorientation angle θ. The initial and final indentation stress (Oind(t=0) and σth), the apparent activation energy and volume (ΔG0 and V*) were calculated. Oind(t=0) and σlh were dependent upon h while AGh was not. V* followed the same dependence upon dislocation density and indentation stress regardless of h indicating that the basic dislocation/obstacle interaction controlling the indentation creep rate is independent of h. Tests performed directly upon grain boundaries of known θ indicated that ind(t=0), σlh,and ΔG0 of the boundaries could be expressed in the same functional form as the Read-Shockley equation for the energy of small angle boundaries. A modified Hall-Petch type equation was developed to express Oind(t=0) OM ,and ΔG0 in terms of Gand L.
Recommended Citation
Bose, Bipasha, "Microstructural Effects on the Nanoindentation Creep of a 2024 Aluminum Alloy at 300K" (2007). Digitized Theses. 4972.
https://ir.lib.uwo.ca/digitizedtheses/4972