Mechanisms of energy dissipation and damping properties of Fe−Mn alloys with a structure of hexagonal ε-martensite

Abstract

The intense operation of machines and mechanisms of today increases the significance of the problem of reducing the level of vibrations and noise by means of high dissipative properties for the materials used in them and stimulates extensive research on the nature of this phenomenon. New effective structural materials based on the Fe−Mn system developed by the authors and recommended for use as damping materials make it possible to solve a very important practical problem, namely, to combine the two mutually exclusive properties of high strength and high damping capacity. The present work is devoted to an analysis of the internal friction of Fe−Mn alloys as a function of the manganese content in them (2–54%), the type of crystal lattice (b.c.c., h.c.p., f.c.c.), the method of production (conventional and powder technologies), the amplitude of the applied stress, and the test temperature. The conditions providing a high damping capacity of the alloys are determined. The authors make an attempt to evaluate qualitatively and quantitatively the contribution of the structural features of the powder alloys to the total level of energy dissipation in the cast and powder alloys, which is responsible for elevation of the level of the dissipative properties. Results of industrial tests of creasted parts are compared with data on conventional parts.