PSI - Issue 50

A.S. Smirnov et al. / Procedia Structural Integrity 50 (2023) 266–274 A.S. Smirnov, A.V. Konovalov,V.S. Kanakin and I.A. Spirina / Structural Integrity Procedia 00 (2022) 000 – 000

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due to active softening occurring in the alloy during plastic deformation. This assumption is confirmed by the microstructure images obtained after deformation (Figs. 3 and 4). In Fig. 3, gray lines show low-angle boundaries with a misorientation of 2 to 15  and black lines show high-angle boundaries with a misorientation of more than 15  . In Fig. 4, recrystallized grains are shown in blue and deformed grains are shown in red. The critical angle of the average lattice misorientation in the grain, at which the grain was supposed to be deformed, was assumed to be equal to 2  (Gorelik et. al., 2005). The images of the microstructures in Figs. 3 and 4 were obtained from specimen regions deformed according to the dependences shown in Fig. 4a. These dependences resulted from the finite element simulation of specimen compression with the Coulomb friction coefficient equal to 0.13 (Smirnov et. al., 2021). The finite element simulation was preceded by finding the coefficients i a in model (1) from minimization of the function

j  

j

z

N

j



i

i

j

n 1

z

n





 

1

i



J a , ,a 

min.



i

0

14

N

(2)

1

j



j

3  n ); j N is the number of experimental i  and i z are the flow stress values calculated

Here, j is the experiment number; n is the number of experiments ( points for the j -th experiment; i is the experimental point number;

by the model and obtained in real tests, respectively.

Fig. 1. Forms of loading I (a), II (b), and III (c) used for model identification.