NITRIDING OF TITANIUM

Journal Article · Fri Jan 01 04:00:00 EST 1960 · Nippon Kinzoku Gakkaishi (Japan)

OSTI ID:4100320

Takamura, A

A kinetic study of the nitriding process of titanium in a nitrogen stream was carried out in order to establish a method to improve the frictional properties of titanium. The diffusion layer formed by nitriding was covered by a very thin compound layer (TiN). The maximum hardness of the diffusion layer was above Vickers 1000, but the rate of its growth was comparatively low. The rate of reaction of titanium with nitrogen was found to follow the parabolic law at 80 to 900 deg , and the rate-controlling process was considered to be the diffusion process in both the compound layer and the diffusion layer. As the rate of growth of the diffusion layer is considered to be controlled exclusively by the solubility and the diffusion coefficients of nitrogen in alpha -titanium, both of which are functions of temperature only, it is necessary to operate at higher temperature and for longer times in order to make the hardened layer deeper. However, the nitriding at a temperature above the transformation point of titanium is not practical because of the formation of surface reliefs produced in the course of beta - alpha transformation and the deformation of material nitrided at high temperature. Therefore it is concluded that the most practical nitriding temperature is about 850 deg C. The diffusion coefficients of nitrogen in alpha -titanium and the compound layer were determined at 850 deg C as follows: D/sub a/= 1.3 x 10-/sup 11/ cm/sup 2//sec and D/sub y/ = 1.4 x 10-/sup 12/ s cm/sup 2//sec. (auth)

• Research Organization: Originating Research Org. not identified
• NSA Number: NSA-15-007812
• OSTI ID: 4100320
• Journal Information: Nippon Kinzoku Gakkaishi (Japan), Journal Name: Nippon Kinzoku Gakkaishi (Japan) Vol. Vol: 24; ISSN NIKGA
• Country of Publication: Country unknown/Code not available
• Language: Japanese

Related Subjects

ALLOTROPY
CHEMICAL REACTIONS
CONTROL
DEFORMATION
DIFFUSION
EQUATIONS
EXPANSION
FRICTION
HARDNESS
HIGH TEMPERATURE
LAYERS
MATERIALS TESTING
METALS, CERAMICS, AND OTHER MATERIALS
NITROGEN
REACTION KINETICS
SOLUBILITY
SURFACES
TEMPERATURE
THICKNESS
TITANIUM
TITANIUM NITRIDES
TITANIUM-ALPHA
TITANIUM-BETA
VICKERS HARDNESS