Fractal modeling the mechanical properties of the metal surface after ion-plasma chrome plating

Abstract

Based on experimental studies, the effect of ion-plasma chrome plating on the wear resistance and mechanical properties of parts has been established, and structural changes in the material have been analyzed. The ion-plasma chrome plating technology ensures chip- and pitting-free operation of the hardened parts and increases their wear resistance by a factor of 1.50 to 1.75. Areas of structural transformation characteristic of secondary hardening phenomena can be observed in the damaged sections. Fractal theory, in particular multifractal analysis using the Renyi equation, has been applied to analyze the non-uniform surface of parts. Models describing the relationship between mechanical properties and multifractal characteristics of the structure are derived: uniformity D 600, orderliness (latent periodicity) Δ = D 1 - D 600 , regularity K = D -600 -D 600 . The adequacy of the models is confirmed by Durbin-Watson statistics at the levels of 2.62 and 3.12. The sensitivity of the investigation multifractal statistical characteristics of cementite to the strength properties σv (0.80) and σ 0.2 (0.96), as well as of these characteristics of ferrite to the plastic properties δ (0.97) and ψ (0.97) has been established. The results allow this approach to be used as an express non-destructive testing methodology for predicting the mechanical properties of metallic materials after ion-plasma chrome plating.