CHAPTER 4
SPECIAL METHODS
This chapter will explain the methods used to measure
the partitioning of elements to the gamma and gamma prime
phases. The convergent beam diffraction method is one
method described extensively in this chapter. Simple
equations are developed which aid in interpreting the
patterns and further allow simulated patterns of
experimental patterns to be generated. The results of the
lattice parameter measurements and strain measurements
made using the CBED method are given in Chapter Five.
Chapter Four also includes a brief section on energy
dispersive analysis, specifically as it relates to the
characterization of the alloys analyzed in this study.
4.1 Convergent Beam Electron Diffraction
(CBED)Methods
A convergent beam electron diffraction pattern is
similar to a selected area diffraction pattern with one
major and self-defining difference: a convergent beam
pattern uses a focussed beam with a large convergence
angle to define the area from which the diffraction
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