Unformatted text preview: t the initial particle radius is negligibly small. Assume particle growth is governed by Be diffusion and can be modeled as r 2 = Dt , where r is the particle radius, D is the diffusivity, and t is the aging time. (b) During this initial aging process, the precipitates maintain coherency with the crystalline host material and thus can be treated as a weak obstacle. Calculate the obstacle shear strength as a function of aging time. Assume that the entirety of the obstacle strengthening in this regime is due to a coherency “misfit” strain (hydrostatic) of ε misfit = 0.01 € (c) Upon reaching the equilibrium volume fraction of precipitate, the particles are found to coarsen with continued aging. During this stage, the size of the precipitate increases accordin...
View
Full Document
 Fall '14

Click to edit the document details