Vyatka State University, Kirov, Russia:

A. I. Skvortsov, Dr. Eng., Prof., Dept. of Materials Science and Design Fundamentals, e-mail: skvorcov@vyatsu.ru

In the case when the main mechanism of internal friction has a magnetomechanical basis, then an increase in the content of graphite in the alloy is accompanied by a decrease in its damping ability, a more compact form of graphite corresponds to a higher damping ability and strength with approximately the same plasticity, and the nature of the correspondence between the value of the ferrite grain and the damping ability depends on compactness of graphite inclusions. The ferrite matrix corresponds to the greatest damping ability due to the effective action of the mechanism of a magnetomechanical nature in comparison with the bainite and martensitic ones. If the main mechanism of internal friction is deformation, then an increase in the content of graphite in the alloy and its less compact shape is accompanied by an increase in the damping ability of the alloy. The highest damping ability of cast iron SCh25 due to the effective action of the mechanism of deformation nature corresponds to the martensitic matrix compared to bainitic and ferritic ones. The maximum value of the complex characteristic δσв among alloys in which the main mechanism of internal friction of a magnetomechanical nature corresponds to graphitized steel after annealing to a ferrite-graphite structure, and among alloys in which the main mechanism of internal friction of a deformation nature corresponds to cast iron SCh25 with a tempered martensite matrix.

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