Korean Institute of Surface Engineering

pISSN : 1225-8024 | eISSN : 3399-8403


공학

한국표면공학회지 (43권5호 224-229)

Pulse Electrodeposition and Characterization of Ni-Si3N4 Composite Coatings

Pulse Electrodeposition and Characterization of Ni-Si3N4 Composite Coatings

;;;
Gyawali, Gobinda;Woo, Dong-Jin;Lee, Soo-Wohn;

Department of Metallurgy and Materials Engineering, Sun Moon University;Korea Institute of Construction Materials;Department of Environmental Engineering, Sun Moon University;
Department of Metallurgy and Materials Engineering, Sun Moon University;Korea Institute of Construction Materials;Department of Environmental Engineering, Sun Moon University;

DOI : 10.5695/JKISE.2010.43.5.224

Abstract

$Ni-Si_3N_4$ nano-composite coatings were prepared by pulse current (PC) electrodeposition and direct current (DC) electrodeposition techniques. The micro-structure of the coatings was characterized by scanning electron microscopy (SEM), vickers microhardness, X-Ray Diffraction (XRD) and wear-friction tests. The results showed that the micro-structure and wear performance of the coatings were affected by the electrodeposition techniques. Pulse current electrodeposited $Ni-Si_3N_4$ composite coatings exhibited higher microhardness, smooth surface, and better wear resistance properties as compared to coatings prepared under DC condition. The $Ni-Si_3N_4$ composite coatings prepared at 50 Hz pulse frequency with 10% duty cycles has shown higher codeposition of nano-particles. Consequently, increased microhardness and less plastic deformations occurred in coatings during sliding wear test. The XRD patterns revealed that the increased pulse frequencies changed the preferred (100) nickel crystallite orientations into mixed (111) and (100) orientations.

Keywords

Composite coatings;Pulse electrodepositon;Microhardness;