An evaluation of nickel-aluminum coatings fabricated with the plasma-spray process

Conference · Sun Dec 31 23:00:00 EST 1989

OSTI ID:5695857

Varacalle, Jr, D J; Knibloe, J R; Smith-Wackerle, V L ^[1]; Walter, J A ^[2]; Irons, G ^[3]

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1. EG and G Idaho, Inc., Idaho Falls, ID (USA)
2. Miller Thermal, Inc., Appleton, WI (USA)
3. TAFA, Inc., Concord, NH (USA)

As part of an investigation of the dynamics that occur in the plasma-spray process, an experimental study of the plasma spraying of nickel-aluminum powder was conducted. The coating experiments used typical process parameters that were varied in a Taguchi fractional factorial design parametric study. Operating parameters were varied around the typical spray parameters in a systematic design of experiments to display the range of plasma-processing conditions and their effect on the resultant coating. Parameters varied include the working gas mixture, power, powder injection location, spray distance, traverse rate, and powder feed rate. Typical operating conditions for the torch of this study were 35 V, 800 A, 100 standard ft{sup 3}/h (scfh) argon primary gas flow, 47 scfh helium secondary gas flow, and 7 lb/h powder feedrate. These parameter settings were used with a 3-in. spray distance and a gun traverse rate of 20 in./sec. The statistical scheme varied around these nominal parameter settings. The coatings were fabricated with ten passes, which yielded relatively even coatings that ranged in thickness from 187 to 603 microns. The coatings were characterized by hardness tests, optical metallography, and x-ray diffraction. Coating qualities are discussed with respect to thickness, hardness, porosity, and phase content.

• Research Organization: EG and G Idaho, Inc., Idaho Falls, ID (USA)
• Sponsoring Organization: DOE; USDOE, Washington, DC (USA)
• DOE Contract Number: AC07-76ID01570
• OSTI ID: 5695857
• Report Number(s): EGG-M-90391; CONF-9011207--1; ON: DE91013208
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360101* -- Metals & Alloys-- Preparation & Fabrication
360102 -- Metals & Alloys-- Structure & Phase Studies
360103 -- Metals & Alloys-- Mechanical Properties
ALLOYS
ALUMINIUM
ALUMINIUM ALLOYS
ALUMINIUM BASE ALLOYS
ARGON
CHALCOGENIDES
COATINGS
COHERENT SCATTERING
CRYSTAL STRUCTURE
DEPOSITION
DIFFRACTION
DIMENSIONS
DISPERSIONS
ELEMENTS
EVALUATION
FLUIDS
GASES
HARDNESS
HELIUM
MATERIALS TESTING
MECHANICAL PROPERTIES
MECHANICAL TESTS
METALS
MICROSCOPY
MICROSTRUCTURE
MIXTURES
NICKEL
NICKEL ALLOYS
NICKEL BASE ALLOYS
NICKEL COMPOUNDS
NICKEL OXIDES
NONMETALS
OPTICAL MICROSCOPY
OXIDES
OXYGEN COMPOUNDS
PLASMA ARC SPRAYING
POROSITY
POWDERS
RARE GASES
SCATTERING
SPRAY COATING
SPRAYED COATINGS
SURFACE COATING
TESTING
THICKNESS
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS
X-RAY DIFFRACTION