TITLE:
Mechanism of Building-Up Deposited Layer during Electro-Spark Deposition
AUTHORS:
Amin D. Thamer, Mohammed H. Hafiz, Baha S. Mahdi
KEYWORDS:
ESD; ESA; Electro-Spark Deposition; IN738L Repairing; NI6625; Surface Repairing of Gas Turbine Blades
JOURNAL NAME:
Journal of Surface Engineered Materials and Advanced Technology,
Vol.2 No.4,
October
24,
2012
ABSTRACT: This paper studies the mechanism of formation of the deposit layer by (ESD) electro-spark deposition process. Inconel 738 substrates are coated with a deposited layer of NI6625 (Inconel 625). Selections of these two alloys have been done because they had wide applications and importance in the industry especially in gas turban blades in inland stations and in aircraft engines. ESD is suggested because it has a low input heat process which eliminates the effect of HAZ in these Ni-superfluous due to their sustainability to micro-cracks. The coating contains many deposited sub-layers coming from evaporated and melted micro-regions as a result of locally high heat generated by discharging a series of capacitors charged and discharged in a controlled manner between electrode and substrate material. The maximum deposition rates at the beginning of the process and decreases until been in a steady state condition due to the nature of the resultant morphology of the created surface.