Effect of plasma nitriding on electrodeposited Ni–Al composite coating

✍ Scribed by N. Daemi; F. Mahboubi; H. Alimadadi

• Publisher: Elsevier Science
• Year: 2011
• Weight: 800 KB
• Volume: 32
• Category: Article
• ISSN: 0261-3069
• DOI: 10.1016/j.matdes.2010.07.007

✦ Synopsis

In this study plasma nitriding is applied on nickel-aluminum composite coating, deposited on steel substrate. Ni-Al composite layers were fabricated by electro-deposition process in Watt's bath containing Al particles. Electrodeposited specimens were subjected to plasma atmosphere comprising of 80% N 2 -20% H 2 , at 500 °C, for 5 h. The surface morphology investigated, using a scanning electron microscope (SEM) and the surface roughness was measured by use of contact method. Chemical composition was analyzed by X-ray fluorescence spectroscopy and formation of AlN phase was confirmed by X-ray diffraction. The corrosion resistance of composite coatings was measured by potentiodynamic polarization in 3.5% NaCl solution. The obtained results show that plasma nitriding process leads to an increase in microhardness and corrosion resistance, simultaneously.