Plastic anisotropy of directionally solidified nickel-base superalloys with columnar-grained and monocrystal structures in conventional and plane-strain compression

Journal Article · Thu Jan 01 04:00:00 EST 1976 · Metall. Trans., A; (United States)

DOI:https://doi.org/10.1007/BF02644033· OSTI ID:7353261

Law, C C ^[1]; Giamei, A F

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1. Pratt and Whitney Aircraft, Middletown, CT

The plastic anisotropy in transverse compression (i.e., the direction of compression, x-axis is perpendicular to the growth direction, z-axis of the specimen) of a directionally-solidified nickel-base superalloy of Hf-modified Mar-M200 composition was studied at 1149 and 1216/sup 0/C. The lateral strain ratio depsilon/sub zz//d epsilon/sub yy/ was found to be in the range of 1.6 to 3.0 and the yield strengths were higher than those of monocrystals yielded along <001>. These data were compared with those predicted from the Hosford-Backofen texture analysis for a model DS structure in which all the columnar grains are parallel to <001> and randomly rotated about this direction. It was shown that the relatively low plastic anisotropy observed experimentally can be explained, by means of the texture analysis, in terms of the scattering in the growth directions of the columnar grains and the nonrandom rotations of the grains about these directions. The relative yield strengths of monocrystals in plane-strain compression in which the direction of elongatiion is parallel to <001> have been analyzed using Bishop-Hill plasticity analysis which shows that the Taylor factor M is equal to ..sqrt..6, independent of orientation of the compression axis. The theoretical result was experimentally verified, using low-carbon Mar-M200 monocrystals tested under plane-strain condition at 1093/sup 0/C. The experimental results are in good agreement with those of the theoretical analysis.

• OSTI ID: 7353261
• Journal Information: Metall. Trans., A; (United States), Journal Name: Metall. Trans., A; (United States) Vol. 7A:1; ISSN MTTAB
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360103* -- Metals &amp; Alloys-- Mechanical Properties
ALLOYS
ALUMINIUM ALLOYS
ANISOTROPY
CHROMIUM
COBALT
COMPRESSION
CRYSTALS
ELEMENTS
HAFNIUM ALLOYS
MECHANICAL PROPERTIES
METALS
MONOCRYSTALS
NICKEL ALLOYS
NICKEL BASE ALLOYS
NIOBIUM ALLOYS
PHASE TRANSFORMATIONS
PLASTICITY
SOLIDIFICATION
STRAINS
TITANIUM ALLOYS
TRANSITION ELEMENTS
TUNGSTEN ALLOYS