Nanolayered multilayer coatings of CrN/CrAlN prepared by reactive DC magnetron sputtering

Barshilia, Harish C and Deepthi, B and Selvakumar, N and Anjana, Jain and Rajam, KS (2007) Nanolayered multilayer coatings of CrN/CrAlN prepared by reactive DC magnetron sputtering. Applied Surface Science , 253. pp. 5076-5083.

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Abstract

Single-phase CrN and CrAlN coatings were deposited on silicon and mild steel substrates using a reactive DC magnetron sputtering system. The structural characterization of the coatings was done using X-ray diffraction (XRD). The XRD data showed that both the CrN and CrAlN coatings exhibited B1 NaCl structure with a prominent reflection along (200) plane. The bonding structure of the coatings was characterized by X-ray photoelectron spectroscopy and the surface morphology of the coatings was studied using atomic force microscopy. Subsequently, nanolayered CrN/CrAlN multilayer coatings with a total thickness of approximately 1 m were deposited on silicon substrates at different modulation wavelengths (). The XRD data showed that all the multilayer coatings were textured along {200}. The CrN/CrAlN multilayer coatings exhibited a maximum nanoindentation hardness of 3125 kg/mm2 at a modulation wavelength of 72 Å, whereas single layer CrN and CrAlN deposited under similar conditions exhibited hardness values of 2375 and 2800 kg/mm2, respectively. Structural changes as a result of heating of the multilayer coatings in air (400-800C) were characterized using XRD and micro-Raman spectroscopy. The XRD data showed that the multilayer coatings were stable up to a temperature of 650C and peaks pertaining to Cr2O3 started appearing at 700C. These results were confirmed by micro-Raman spectroscopy. Nanoindentation measurements performed on the heat-treated coatings revealed that the multilayer coatings retained hardness as high as 2250 kg/mm2 after annealing up to a temperature of 600°C.

Item Type: Article
Subjects: CHEMISTRY AND MATERIALS > Chemistry and Materials (General)
Depositing User: Mr N Selvakumar
Date Deposited: 13 Dec 2011 06:41
Last Modified: 13 Dec 2011 06:41
URI: http://nal-ir.nal.res.in/id/eprint/9940

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