Avaliação da resistência ao desgaste de revestimentos de Zn-Ni eletrodepositados com partículas de Al2O3

Abstract

The great technological evolution verified nowadays can be proportionally related to the increase in the use of metals applied in the most diverse industrial sectors, being the corrosive mechanisms and abrasive wear examples of factors capable of causing a very severe deterioration in every material containing metallic components. Thus, there is a need for further studies to protect them against corrosion and wear, increasing their durability and improving their mechanical, corrosive, and tribological properties. Using the electrodeposition of Zn-Ni alloys, the results will be evaluated as a function of the variation in the concentration of composite material in the electrolytic bath, in this case aluminum oxide (Al2O3 alumina). To then, verify if the insertion of the composite in the metallic matrix of the alloy in the substrate (in this case AISI 4340 carbon steel) really occurred, besides analyzing which approximate value of its concentration presents significantly superior results of the mechanical properties compared to the alloy deposited without the insertion of alumina in the bath. In the degradation of metals, the wear mechanisms present one of the most important means of deterioration, its verification in this work will be carried out through the morphological analysis of the coating applied with the tribology test (using a tribometer), the knoop microhardness test and the characterization by Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS) on the cross section of the coating. An adverse to the expected behavior was observed, since the electrodeposited samples at the concentration of 75 g L-1 when analyzed by EDS did not present alumina in their coating. As the concentration of alumina in the bath increased, there was a proportional increase in the hardness, and consequently the greater debondings are a function of this increase in the coating hardness.