Al₂O₃ reinforced Fe–Al composite coatings prepared by double glow discharge technique

Abstract

Alumina (Al₂O₃) particles reinforced iron aluminide coatings (Fe–Al coatings) were prepared on the surface of 316L stainless steel at only 580°C by a novel approach, namely double glow discharge technique. The chemical composition and morphology of the coatings were characterised by means of glancing angle (1°) X-ray diffractometry, X-ray photoelectron spectroscopy and scanning electron microscopy (SEM) respectively. The hardness, wear and corrosion behaviours of the aluminide coatings were also evaluated. The results indicated that the aluminide coatings exhibited a good wear and corrosion resistance since Al₂O₃ particles were well distributed in the coatings. The friction coefficient of the composite coatings increased first and then decreased with the increment of Al₂O₃ particles, meanwhile the corrosion potential and microhardness tended to increase. Finally, the wear mechanisms of the coatings were discussed.

Keywords:

• Double glow
• Al₂O₃
• Aluminides
• Coating
• Wear
• Corrosion

The authors gratefully acknowledge the financial support of the National Natural Science Foundation of China (grant nos. 51071086, 50571045 and 51205196), the Doctoral Foundation of Ministry of Education of China (grant 20123218120029) and the special foundations for significant achievements of Jiangsu Province of China (grant no. BA2012124).