PSI - Issue 6

Ivan Smirnov et al. / Procedia Structural Integrity 6 (2017) 196–200

199

Ivan Smirnov et al. / Structural Integrity Procedia 00 (2017) 000 – 000

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strain conditions prevail and that LEFM is applicable. Unfortunately, the volume dimensions of the UFG material blanks do not yet allow the production of samples with similar dimensions of coarse-grained material samples. Thus, one should choose either to satisfy the requirements for the dimensions of the samples or compare test results for the materials with the same sample dimensions.

1200 1500 1800

300 600 900

UFG CG

Force (N)

0.0 0.1 0.2 0.3 0.4 0.5 0

Load line displacement (mm)

Fig. 3. Typical load-displacement plots in fracture toughness tests of titanium Grade 4. CG - coarse-grained state; UFG - ultrafine-grained state.

Fig. 4. Fracture surfaces of titanium Grade 4 after impact toughness tests (a, b) and fracture toughness tests (c,d). a) and c) coarse-grained state; b) and d) ultrafine-grained state.