SEARCH RESULT

Electro-spark Deposition (ESD) technique is a surface treatment process to produce hard and wear resistant coating on metallic materials [1,2]. Micro-arc Oxidation (MAO) process; also called as Plasma Electrolyte Oxidation (PEO) is a promising surface modification technique to produce a ceramic based coating on the valve metals in a suitable electrolyte [3,4]. In this study, to develop a hard and wear resistant coating on the Ti6Al4V alloy, firstly Al electrode material was deposited on the substrate by using ESD technique and then MAO process was applied in the electrolyte (NaAlO2 and KOH). In the previous work [5], the ESD process was employed in the air while the duplex coating was fabricated on the Ti6Al4V alloy by using ESD and MAO process. However, the present ESD was employed in a shielding gas (argon). Thus, the only aluminium-based phases were obtained in the ESD coating. Then, the MAO process was applied to improve phase structure and tribological properties of the aluminium alloyed. Phase structure, elemental composition, hardness and wear resistance of the duplex coating were analysed by using an X-Ray Diffractometer (XRD), Scanning Electron Microscopy (SEM), EDX, micro Vickers tester and tribometer. The results indicated that the outer layer consists of the -Al2O3 (Corundum) and - Al2O3 phases, while Al and Al3Ti phases were detected in the ESD coated layer. So, hardness and wear resistance of the duplex coating were improved with an increasing the present -Al2O3 (Corundum) phase.

International Symposium on Light Alloys and Composite Materials
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