Investigation on Electrochemical Cathodic Protection for Cavitation-Erosion Reduction of Anodized Al Alloy.

This study investigated the damage prevention potential range of anodized 5083-H321 aluminum alloy under a cavitation-erosion environment in seawater. Various applied potential conditions were determined through the cathodic polarization experiment. Then cavitation-erosion experiments were conducted with the applied potentials and the current density, weight loss, and surface damage depth were analyzed. The results presented excellent cavitation-erosion resistance in the concentration polarization section (-1.0~-0.8 V).

Cavitation Damage Characteristics of Shot Peened ALBC3 Alloy.

Copper alloys have widely used for marine plants, ship building equipment, and renewable energy facilities under marine environment due to its excellent castability, durability, and corrosion resistance. In this study, the surface of ALBC3 alloy was modified with shot peening time to improve the strength and cavitation characteristics. For evaluation of cavitation resistance, cavitation experiments for the non-shot peened and shot-peened specimens were performed to investigate the extent of damage and determine the weight loss. As a result, the shot peened ALBC3 alloys improved cavitation resistance. In particular, the shot peening time of 3.5 min was considered to be the optimum shot peening condition since it presented an improvement of 35.7% in cavitation resistance.

Cavitation Erosion Behavior of Electroless Ni-P Coating and Optimization of Process Parameter Using Analysis of Variance with Orthogonal Array.

This study investigated the cavitation erosion resistance of electroless Ni-P (EN) coated gray cast iron (GCI) in seawater solution. Furthermore, the optimum coating design parameters were examined to minimize cavitation erosion damage through analysis of variance (ANOVA) based on the L9 orthogonal array. In this study, four coating design factors were used: concentration of source of nickel (A), concentration of reducer agent (B), deposition temperature (C), and pressure of shot peening (D). In accordance with the regulation of the modified ASTM G32, the cavitation erosion experiment was conducted for 1 hour in a seawater solution to find the optimum design parameters which can minimize the cavitation erosion damage. Besides, ANOVA was performed to verify the contribution of each coating design parameter. As a result, the concentration of reducer agent among the EN process parameters was determined as the most significant factor in the cavitation erosion behavior.