PSI - Issue 81

Serhiy Fedak et al. / Procedia Structural Integrity 81 (2026) 305–309

307

level, this breakdown involves an intensification of slip on existing planes and/or the initiation of slip along new crystallographic systems (Fig. 2).

Fig. 2. Cracked dispersoids of AMg6 alloy (x30 000).

When uniformly sized dispersoids simultaneously destrtoy throughout the material, an instantaneous increase in plastic deformation occurs, its magnitude depending on the number of fractured dispersoids n(  i ) and the inherent mechanical properties of the material. The tensile process up to the limit of  st is characterized by alternating phases of strengthening (linear segments) and weakening (sudden increases in deformation). Article by Yasniy and Glad’o (2002) (Fig. 3) outlines the relationship between the magnitude of these instantaneous deformation increments and the corresponding maximum tensile stress.

 , MPa

 р (  і )  р (  7 )  р (  6 )  р (  5 )  р (  4 )  р (  3 )  р (  2 )  р (  1 )

*

*

280

*

260

240

220

0,004

0,008

0,012

 (  i ), mm/mm

Fig. 3. Dependence of the value of instantaneous strain increments on the stress level during stretching of AMg6 alloy specimens. Different symbols correspond to 12 specimens tested under the same conditions. 3. Analysis of the jump-like creep of AMg6 aluminum alloy The experimental study analyzed changes in deformation parameters observed during material strengthening phases. Key to this analysis was identifying the coefficient of proportionality that relates the incremental deformation  е і and the stress  і in the strengthening area і Е  . These sections exhibit a linear dependence on the deformation diagram, allowing their parameters to be determined using the formula:



і 

(1)

 

Е

і

е





і

і Е  tends to change as the stress value  p (  i ) decreases (Fig. 4).

The coefficient