Chemical and Materials Engineering Vol. 3(2), pp. 29 - 37
DOI: 10.13189/cme.2015.030203
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Effect of Plasma Enhanced Chemical Vapor Deposition of Tetraethylorthosilicate on the Friction and Wear Loss of Plasma Electrolytic Oxidized Aluminum 6082


Ahmad R Rastkar *
Laser and Plasma Research Institute, Shahid Beheshti University, Iran

ABSTRACT

The surface of 6082 aluminum alloy was coated by plasma electrolytic oxidation (PEO) and then treated by plasma enhanced chemical vapour deposition (PEVCD) of tetraethylorthosilicate (TEOS), oxygen and argon. The PEO electrolyte was alkaline and consisted of potassium hydroxide and sodium aluminates. A pulsed DC power supply with the frequency of 18 kHz was utilized to perform PEO and PECVD treatments. In the PEO process, the electrolyte was at boiling temperature. PECVD was carried out at temperature of 400℃. The working pressure of vacuum chamber was 10 mbar. The surfaces were characterised using XRD, optical, AFM and SEM microscopy, EDX analysis, Vickers microhardness test and ball on disc wear test methods. The thickness of PEO coated layers was more than 80 μm. α-Al2O3 was the main oxide compound in the coatings. PECVD treatment resulted in the diffusion of silicon in the surface oxide layer. However, up to 16% silicon was identified in the top surface layers after PECVD treatment, no considerable variation in the thickness of the alumina layer or new layers were observed on the surface of the samples. PEO coating generated very hard surfaces with highly varying coefficient of friction. PECVD treatment reduced the hardness slightly, modified the friction behavior and reduced the wear loss several times.

KEYWORDS
Adhesive Wear, Surface Roughness, Hardness, Coating, Wear Resistance, Stick-slip

Cite this paper
Ahmad R Rastkar (2015). Effect of Plasma Enhanced Chemical Vapor Deposition of Tetraethylorthosilicate on the Friction and Wear Loss of Plasma Electrolytic Oxidized Aluminum 6082. Chemical and Materials Engineering, 3 , 29 - 37. doi: 10.13189/cme.2015.030203.