Electro-spark deposited coatings for protection of materials

Conference · Tue Aug 01 04:00:00 EDT 1995

OSTI ID:416503

Johnson, R N ^[1]

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1. Battelle Pacific Northwest Lab., Richland, WA (United States)

Electro-Spark Deposition (ESD) is a micro-welding process that uses short duration, high-current electrical pulses to deposit or alloy a consumable electrode material onto a metallic substrate. The coating is fused (metallurgically bonded) to the substrate with such a low total heat input that the bulk substrate material remains at or near ambient temperature. Rapid solidification of the deposit typically results in an extremely fine-grained deposit that may be amorphous for some materials. Nearly any electrically conductive metal, alloy or cermet can be applied to metallic substrates. The ESD process allows multi-layer coatings to be built-up using different materials to create graded structures or surface compositions that would be difficult to achieve by other means. A series of iron-aluminide coatings based on Fe{sub 3}Al and FeAl in combination with refractory metal diffusion-barrier coatings and supplementary additions of other elements are in corrosion testing at ANL. The most recent FeAl coatings are showing a factor of three better corrosion performance than the best previous coatings. Technology transfer activities are a significant portion of the ESD program effort. Notable successes now include the start-up of a new business to commercialize the ESD technology, major new applications in gas turbine engines and steam turbine blade coatings, and in military, medical, metal-working, and recreational equipment applications.

• Research Organization: Oak Ridge National Lab., TN (United States)
• OSTI ID: 416503
• Report Number(s): ORNL/FMP--95/1; CONF-9505204--; ON: DE96001412
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM ALLOYS
CORROSION RESISTANCE
DEPOSITION
ELECTRODEPOSITED COATINGS
IRON ALLOYS
MICROSTRUCTURE
SOLIDIFICATION
WELDING