Effect of grain size on yield strength of Ni/sub 3/Al and other alloys

Journal Article · Fri Jul 01 00:00:00 EDT 1988 · J. Mat. Res.; (United States)

OSTI ID:7202604

Takeyama, M; Liu, C T

This paper analyzes the effect of grain size on yield stress of ordered Ni/sub 3/Al and Zr/sub 3/Al, and mild steels that show Lueders band propagation after yielding, using the Hall--Petch relation, sigma/sub y/ = sigma/sub 0/+k/sub y/ d/sup -1//sup ///sup 2/, and the new relation proposed by Schulson et al., sigma/sub y/ = sigma/sub 0/+kd/sup -(//sup p//sup +1)/2/ (Schulson et al., Acta Metall. 33, 1587 (1985)). The major emphasis is placed on the analysis of Ni/sub 3/Al data obtained from published and new results, with a careful consideration of the alloy stoichiometry effect. All data, except for binary stoichiometric Ni/sub 3/Al prepared by powder extrusion, fit the Hall--Petch relation, whereas the data from boron-doped Ni/sub 3/Al and mild steels do not follow the Schulson relation. However, no conclusion can be made simply from the curve fitting using either relation. The results are also discussed in terms of Lueders strain and alloy preparation methods. On the basis of the Hall--Petch analysis, the small slope k/sub y/ is obtained only for hypostoichiometric Ni/sub 3/Al with boron, which would be related to a stronger segregation of boron in nickel-rich Ni/sub 3/Al. In addition, the potency for the solid solution strengthening effect of boron is found to be much higher for stoichiometric Ni/sub 3/Al than for hypostoichiometric alloys.

• Research Organization: Metals and Ceramics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831
• OSTI ID: 7202604
• Journal Information: J. Mat. Res.; (United States), Vol. 3:4
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM ALLOYS
GRAIN SIZE
YIELD STRENGTH
NICKEL ALLOYS
STEELS
ZIRCONIUM ALLOYS
BORON ADDITIONS
GRAIN BOUNDARIES
POWDERS
ALLOYS
BORON ALLOYS
CRYSTAL STRUCTURE
IRON ALLOYS
IRON BASE ALLOYS
MECHANICAL PROPERTIES
MICROSTRUCTURE
SIZE
360103* - Metals & Alloys- Mechanical Properties