International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

The direct problem in ultrasonic testing (UT) is: “Evaluation of attenuation coefficient by means velocity of ultrasonic wave propagation, frequency and grain size in polycrystalline materials”. The inverse problem in UT is formulate as “Non-destructive evaluation of grain size by measurement of acoustical characteristics”. The values of acoustical characteristics (V V f ) L T L ; ;α ; are measured, according ASTM E 494:2015. In this article a equation for grain size (D) is derived.

The evaluation of yield stress -σ_S is frequently encounter in material testing. In this method there is necessity of manufacture of test-tube from tested material or detail and made tension test. There is destructive method. For many details there is not acceptable. In material testing there is interest to non-destructive evaluation of yield stress σ_S for the materials and details. In this paper is lock at possibility for non-destructive evaluation of yield stress σ_S by means measure Brinel’s hardness – HB or velocities of propagation of longitudinal and transversal ultrasonic waves – V_L and V_T in tested materials and details.

The evaluation of fatigue limit-σ₋₁ for AlSi₇Mg, AlCu₆Mn aluminum alloys is frequently encounter in material testing. In this method there is necessity of manufacture of test-tube from tested material or detail and made tension test.. There is destructive method. For many details there is not acceptable. Calculated in the usual ways fatigue limit appear only their statistical averaging between a number of structural factors indicating the influence. In material testing there is interest to non-destructive evaluation of fatigue limit σ₋₁ for the specimens and details. In this paper is lock at possibility for non-destructive evaluation of fatigue limit σ₋₁ by means measure velocities of propagation of longitudinal and transversal ultrasonic waves – V_L and V_T in tested materials and details.