Preliminary study of oxidation-resistant coatings on refractory-metal thermocouple sheaths

Conference · Sat Sep 01 00:00:00 EDT 1984

OSTI ID:6230648

Wilkins, S C

The need to make reliable temperature measurements up to 2200/sup 0/C or higher in steam environments during in-pile nuclear fuel damage tests led to a search for oxidation-resistant coatings for the refractory-metal sheaths used to enclose and protect thermocouples used for such measurements. Iridium, thoria, and thoria-over-iridium coatings were separately sputter-deposited on molybdenum-rhenium alloy protection tubes for evaluation. The coated samples were individually heated in flowing steam in an induction furnace. An extension tube welded to each sample was connected to a vacuum pump and gauge; failure of the sample was detected by noting the degradation of the vacuum maintained in the sample. Relatively heavy coatings of iridium provided a modest degree of oxidation protection at the temperatures of interest. Thoria coatings provided no significant protection at those temperatures, compared to uncoated control samples.

• Research Organization: EG and G Idaho, Inc., Idaho Falls (USA)
• DOE Contract Number: AC07-76ID01570
• OSTI ID: 6230648
• Report Number(s): EGG-M-07484; CONF-8409109-6; ON: DE85003436
• Resource Relation: Conference: Industrial temperature measurement symposium, Knoxville, TN, USA, 10 Sep 1984
• Country of Publication: United States
• Language: English

Related Subjects

22 GENERAL STUDIES OF NUCLEAR REACTORS
PROTECTIVE COATINGS
CORROSION RESISTANCE
TESTING
REFRACTORY METALS
THERMOCOUPLES
IRIDIUM
NUCLEAR FUELS
OXIDATION
ALLOYS
CHEMICAL REACTIONS
COATINGS
ELEMENTS
ENERGY SOURCES
FUELS
MATERIALS
MEASURING INSTRUMENTS
METALS
PLATINUM METALS
REACTOR MATERIALS
TRANSITION ELEMENTS
220300* - Nuclear Reactor Technology- Fuel Elements