Utilisation of electrospark deposition to restore local oxidation resistance properties in damaged NiCoCrAlY and CoNiCrAlY coatings

作者：Farhat R; Brochu M^*

来源：Canadian Metallurgical Quarterly, 2012, 51(3): 313-319.

DOI：10.1179/1879139512Y.0000000019

• Electrospark deposition
• NiCoCrAlY
• CoNiCrAlY
• Oxidation
• alpha-Al2O3
• Repair

The electrospark deposition (ESD) technique has been studied as a potential method to locally repair damaged MCrAlY coatings, permitting restoration of the oxidation properties. The results show that for both the NiCoCrAlY and CoNiCrAlY systems, the ESD process produced an Al supersaturated solid solution, which upon heating, decomposed into the equilibrium gamma and beta phases. The oxidation products developed at the surface of the ESD were similar in evolution and nature to the scale produced on the substrates, but the thickening was found to be approximately double that of the substrate. This increased oxidation response was associated with a more homogeneous distribution of Al near the surface, and a shorter, faster diffusion path for diffusion towards the surface created by the small grain size of the ESD deposit.

• 出版日期2012-7