Reaction of boride coatings with a molybdenum substrate

Journal Article · Tue Jul 01 04:00:00 EDT 1975 · Inorg. Mater. (USSR) (Engl. Transl.); (United States)

OSTI ID:7361657

Borisova, A L; Dzyadykevich, Yu V; Sosnovskii, L A

The formation kinetics and structure of phases formed when boron coatings are diffusion deposited on Mo substrates were studied. The results of experiments showed that the Mo/sub 2/B/sub 5/ phase in a boride coating is thermally unstable and is rapidly converted to ..cap alpha..-MoB at relatively low temperatures (1000 to 1100/sup 0/C). The loss of boron to the gas phase or the solid solution can be compensated by increasing the thickness of the ..cap alpha..-MoB phase in the coating. However, the monoboride thickness should not be increased above 60 to 70 ..mu.., because its further increase heightens the brittleness and leads to the appearance of cracks and pores in the coating; the adhesion between the metal and coating is impaired. Therefore protective measures must be taken when boride coatings on Mo operate for prolonged periods above 1400/sup 0/C.

• Research Organization: Inst. of Problems in Materials Science, Kiev
• OSTI ID: 7361657
• Journal Information: Inorg. Mater. (USSR) (Engl. Transl.); (United States), Journal Name: Inorg. Mater. (USSR) (Engl. Transl.); (United States) Vol. 11:7; ISSN INOMA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360105* -- Metals & Alloys-- Corrosion & Erosion
360201 -- Ceramics
Cermets
& Refractories-- Preparation & Fabrication
BORIDES
BORON
BORON COMPOUNDS
CHEMICAL REACTIONS
COATINGS
DEPOSITION
DIFFUSION COATING
DIFFUSION COATINGS
ELEMENTS
KINETICS
METALS
MOLYBDENUM
MOLYBDENUM BORIDES
MOLYBDENUM COMPOUNDS
REACTION KINETICS
REFRACTORY METALS
SEMIMETALS
SUBSTRATES
SURFACE COATING
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS