pr 7 a 
energy 10) 
homage”: 
10 ; poll} 
wi 174 2 
other 3 
Je Fil 
samples 
redline 
pane 
100 nm 
a) light field; b) dark field 
Fig.l The electronic micrography (HREM) of Al-8,6%At.Li alloy heat treated 
The testing of mentioned alloys resistivity confirm the start and the acting of the reaction of 
homogenous ordering, which preced the forming of 8’ precipitates through decreasing of resistivity, 
in case of long distance ordering, (4). Recent determination of X-ray diffraction at low angles and 
HREM investigations realised on quenched samples with 7%At.Li show the presence of ordering 
microdomain without modification of Li content from inside, (5). 
The analyse of order-disorder phenomenon was treated thermodynamic through the variation of free 
energy versus chemical composition of the phenomenon which take place at the aging of Al-Li 
alloys, Fig.2. 
Fig 3 
x Disordered 
Between 
i | yOordered Till 
F- Ihe as nf 
Composition /atomic percent B/ —> Wil 
Fig.2. Diagram of free energy against composition with nn 
a metastable state in the curve of the ordered phase, (6) 
242