J. Chmiela

Fracture surface — fractal or multifractal?

Applying projective covering (PCM) and box-counting methods (for mutually perpendicular profiles), fracture surfaces of ductile and brittle materials were studied. Convergence of results of the compared fractal dimensions calculation methods was found and a multifractal nature of uneven surfaces was proved.

Logistic description of alloy hardness profile

Abstract Using logistic and log–logistic functions a fractal characterization of gradient structure components was performed. Equations were derived that describe the relations between the hardness and the fractal characteristics of an alloy.

Lacunarity Term as a Basis of Multiscale Quantification of Structural Components Distribution Inhomogeneity of Multiphase Materials

Abstract The paper presents the quantification results of the inhomogeneity of phase distribution in intermetallic alloys from the Mg-Al-Sr system after die-casting and gravity casting, the quantification results of phase β of alloy Ti-6-4 after hydrogen treatment and cyclic heat treatment, and of intragranular regions of diverse crystallographic orientation in the copper microstructure in a state of strain and in a recrystallized state. The quantification of the distribution inhomogeneity, based on the concept of directional lacunarity, is effective and precisely detects the size of inhomogeneity and the degree of its intensity, irrespective of the morphology of microstructural components. An analytical description of inhomogeneity allows comparing the results of quantification, regardless of the size of the sets analyzed.