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non-specialized standard measuring devices to determine the delay time of the
passage of the acoustic signal. On this basis, an installation was established to
determine the velocity of longitudinal and surface acoustic waves in the frequency
range of 0.1 - 10 MHz for non-destructive testing. Acoustic waves are excited by
contact piezoelectric transducers and received by both piezoelectric transducers and
contactless laser receivers.
A device based on ultrasonic flaw detector, digital oscilloscope and comparison
samples was created, suitable for measuring the velocity of surface waves in
production conditions with an error in measuring the delay time of the acoustic signal
~ 4 ns. Comparison samples were made with different SAW for calibration of
piezoelectric contact converters in which the excitation and recording prisms are
rigidly connected. Measurements of the SAW rate in the comparison samples were
performed using laser methods.
The effect of gas phase flooding on the velocity of surface acoustic waves of
low carbon steel was investigated. Floods have been found to increase the speed of
these waves.
The distribution of velocity changes of surface acoustic waves in samples of low
carbon steels subjected to plastic tensile deformation was investigated. The reduction
of the acoustic wave velocity in the area of plastic tensile deformation is
experimentally shown. Studies of velocity distribution in these samples have shown
the ability to detect areas with local plastic deformation, based on local velocity
changes. For specimens subjected to plastic tensile deformation, the porosity
distribution was also determined by hydrostatic weighing. It is shown that the
decrease in the SAW rate corresponds to the porosity under conditions of plastic
tensile deformation.
The practical importance of the results obtained in the creation of techniques
that allow to determine the distribution of the speed of the SAWs in the objects of
control in order to assess their condition. In practice, the results of the dissertation
were used to control the adhesive strength of the gas-thermal coatings of the
