Fractal dimension and effects of correlation of the mesostructure of the surface of plastically deformed iron silicide polycrystals and austenitic corrosion-resistant steel

The mesorelief of the surface of plastically deformed specimens is characte rized by a correlation function. It makes it possible to determine the frac tal dimension D, and the correlation length DeltaL from surface images of t he studied specimens obtained under light and scanning electron microscopes . It is shown that two modes of behavior of the correlation function can be distinguished for specimens of iron silicide and austenitic steel broken i n the process of active stretching. In one mode D-c and DeltaL characterize the mesorelief of the surface at scale levels less than the grain size (D- cl, DeltaL(1)) and in the other they describe it at scale levels on the ord er of several grains (D-c2, DeltaL(2)). The behavior of D-cl, DeltaL(1), D- c2, and DeltaL(2) is studied as a function of the distance from the head to the breakage place for specimens of iron silicide and as a function of the degree of plastic deformation for specimens of corrosion-resistant steel. The characteristics increase stage-by-stage with increase in the degree of plastic deformation until the specimen fails.