Steady state creep behavior of an Al-Al{sub 2}O{sub 3} alloy

Journal Article · Sat Mar 01 04:00:00 EST 1997 · Acta Materialia

DOI:https://doi.org/10.1016/S1359-6454(96)00225-X· OSTI ID:483641

Pandey, A B ^[1]; Mishra, R S ^[1]; Paradkar, A G; Mahajan, Y R ^[1]

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1. Defence Metallurgical Research Lab., Hyderabad (India)

The Al-Al{sub 2}O{sub 3} alloy produced by powder metallurgy route has been tested under compression creep in the temperature range 573--723 K to evaluate the steady-state creep mechanisms. The steady state creep data covering almost five orders of magnitude in creep rate shows two distinct regimes of creep deformation at all the temperatures. In the high stress regime (region-II), the creep data shows high and variable apparent stress exponents, 25--30 and high apparent activation energy, 372 kJ/mol. However, in the low stress regime (region-I), the lower values of stress exponents, 7--11 and activation energy, 85 kJ/mol are observed. The TEM micrographs of the uncrept and crept specimens exhibit subgrains with Al{sub 2}O{sub 3} particles lying on the subgrain boundaries. The high stress regime data was examined in terms of pipe-diffusion controlled constant substructure creep model and thermally activated detachment controlled diffusional creep model and pipe-diffusion controlled stress dependent substructure model. Thermally activated detachment controlled diffusional creep mechanism appears to be more appropriate for the present data.

• OSTI ID: 483641
• Journal Information: Acta Materialia, Journal Name: Acta Materialia Journal Issue: 3 Vol. 45; ISSN 1359-6454; ISSN ACMAFD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ACTIVATION ENERGY
ALUMINIUM
ALUMINIUM OXIDES
COMPOSITE MATERIALS
CREEP
DIFFUSION
DISLOCATIONS
EXPERIMENTAL DATA
POWDER METALLURGY
STRESSES