ps_4 - Briefly explain. Y = Y(T) = Y o exp [E y /k B T] and...

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Problem Set 4 E-344 Due: Thursday, 29 October, 2005 Fall 2005 at beginning of lecture 1. Barium titanate (BaTiO 3 ) is a crystalline ceramic material. It’s unit cell can be represented with a barium ion in the cube center, titanium ions at the cube corners, and oxygen ions centered on the cube edges. (A) Use the Miller index notation to describe the positions of each of these ions in the unit cell. (B) Confirm that the unit cell gives the proper stoichiometry of 1 Ba, 1 Ti and 3 O ions. (C) Confirm that this unit cell has a net neutral charge. 2. On the same graph, SKETCH a plot of lnY vs 1/T and lnZ vs 1/T where Y(T) and Z(T) are given by the following expressions. Identify the slope and intercept of each line. Which of these two expressions could be used to model the temperature dependence of viscosity?
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Unformatted text preview: Briefly explain. Y = Y(T) = Y o exp [E y /k B T] and Z = Z(T) = Z o exp[-E z /k B T] 3. Powder processing is often used to make ceramic parts. These, however, often contain significant amounts of porosity which can affect many important properties of the resulting ceramic piece. Imagine that a spherical ball bearing with a diameter of 1 mm is to be be made from spherical powder particles with a diameter of 10 m m. Calculate the volume fraction of porosity in the powder ball-bearing specimen prior to any compaction and sintering. Then, assuming a fully dense piece after compaction and sintering, calculate the percent shrinkage experienced along the ball bearing diameter assuming isotropic shrinkage....
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This note was uploaded on 10/03/2009 for the course E E344 taught by Professor Libera during the Spring '09 term at Stevens.

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