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Subboundary characterization and creep deformation in investment cast Ti-48Al-2Nb-2Cr

Book ·
OSTI ID:78367
 [1];  [2]
  1. Los Alamos National Lab., NM (United States). Materials Science and Technology Division
  2. Michigan State Univ., East Lansing, MI (United States). Dept. of Materials Science and Mechanics

Subgrain boundaries (subboundaries) in a creep deformed investment cast Ti-48Al-2Nb-2Cr specimen were characterized. A multi-stress drop test was performed at temperature 765 C and stresses from 276 MPa to 103 MPa. The stress exponent n = 7. Subboundaries were observed both in equiaxed {gamma} grains and within {gamma} laths in lamellar grains. Dislocations within the subboundaries are characterized to be ordinary 1/2{l_angle}110] dislocations. Subboundaries are found to occur on many crystallographic planes and no preferred crystallographic planes are found for subboundary formation in the crept TiAl specimen. Misorientations across the subboundaries are less than 1{degree}. Analysis of subboundary formation mode indicates that the creep deformation in TiAl is pure metal type.

OSTI ID:
78367
Report Number(s):
CONF-941144--; ISBN 1-55899-265-0
Country of Publication:
United States
Language:
English