2.2.5 Ordering Reactions and Kinetics .... 31
2.2.5.1 Binary Alloys 31
2.2.5.2 Ternary Alloys 35
2.2.6 Ni-Al N3AI 36
2.3 Diffraction Patterns: NixMo Phases/
N3AI 40
2.3.1 DO22 Reciprocal Lattice 40
2.3.2 Dla/Pt2Mo/Ll2 Reciprocal Lattices..42
2.3.3 SRO (1, 1/2, 0) Scattering 46
2.3.4 Variant Imaging 46
2.3.4.1 DO22: N3M0 47
2.3.4.2 Da: N4M0 47
2.3.4.3 Pt2Mo: N2M0 51
3 EXPERIMENTAL PROCEDURE 53
3.1 Composition 53
3.2 Heat Treatments 54
3.3 Characterization: Methods of Analysis ....55
4 SPECIAL METHODS 61
4.1 Convergent Beam Electron Diffraction
(CBED) Methods 61
4.1.1 Experimental Technique 63
4.1.2 HOLZ Lines (High Order Laue
Zone Lines) 66
4.1.3 Indexing HOLZ Lines 72
4.1.4 Lattice Parameter Changes 89
4.1.5 The Effect of Strain and
Non-Cubicity on Pattern Symmetry... 91
4.2 Energy Dispersive Methods 97
5 RESULTS 106
5.1Microstructural Characterization 106
5.1.1 As Extruded RSR 197 and RSR 209
Alloys 106
5.1.2 RSR 197-As Solution Heat Treated
and Quenched 106
5.1.3 General Microstructural Features..Ill
5.1.4 RSR 197 Aging Ill
5.1.4.1Solution Heat Treated,
Quenched and Aged at
760 C for up to 100
Hours Ill
IV