Caracterización electroquímica de recubrimientos Zn-Al sobre fundición nodular grado 2, obtenidos por proyección térmica por flama con alambre

Abstract

La proyección térmica o rociado térmico es una tecnología que implica calentar un material que está en forma de polvo o alambre y llevarlo a un estado fundido o semifundido, para luego propulsarlo mediante una corriente de gas o aire comprimido y depositarlo sobre un sustrato metálico, cerámico o polimérico, que tenga condiciones de rugosidad adecuadas. La investigación realizó la caracterización electroquímica mediante las técnicas de espectroscopia de impedancia electroquímica y ruido electroquímico de una aleación Zn-15Al depositada sobre una fundición nodular grado 65-45-12 (2), por medio de la técnica de proyección térmica por llama con alambre, donde el recubrimiento de Zn-Al presenta buena homogeneidad, buena adherencia y una mejora sustancial en la resistencia a la corrosión.

Evaluation of the corrosion resistance of a Ni-P coating deposited on additive manufacturing steel: A dataset

“…A three-electrode electrochemical cell is implemented, composed by a SCE electrode as reference, a graphite plate as counter electrode and the specimen as working electrode. The working electrolyte was 0.1 M NaCl (low-medium aggressive corrosion) [6] . The sweep frequency for the electrochemical impedance spectroscopy data was from 10 4 to 10 −1 , acquiring 10 points/decade, a sine wave is used as a disturbance to the system with amplitude of 10 mV.…”

Evaluation of the corrosion resistance of an additive manufacturing steel using electrochemical techniques

“…From the phase angle diagram, Figure 9, the strand evidence the formation of only one time constant until 504 hours of evaluation, however, for 1080 and 1320 hours of immersion it is observed the appearance of 2time constants one located at medium frequencies and another at low frequencies, aspect linked to the appearance of oxides on the surface, depending on the electrochemical behavior seen in the curves, the literature reports that the formation of oxides on the surface occurs as the appearance of a porous and poorly adherent layer, which does not limit the corrosion process to continue. [38][39][40][41]44]. The AM steel, shows the appearance of a single time constant located at medium frequencies for the first hours of evaluation, for 1320 h, a shift towards low frequencies is detailed [13,38,42].…”

“…In AM steel there is a small variation between 504 h and 240 h, achieving a very reduced increase in corrosion resistance, this is due to the formation of a small layer of protective oxides, however, the general behavior of steel is in decay, and the layer of oxides formed does not limit the corrosion process [8], [44].…”