High temperature precipitation hardening in Y{sub 2}O{sub 3} partially-stabilized ZrO{sub 2} (Y-PSZ) single crystals -- 3: Effect of solute composition and orientation on the hardening
- Univ. Sevilla (Spain). Dept. de la Materia Condensada
- Case Western Reserve Univ., Cleveland, OH (United States). Dept. of Materials Science and Engineering
High temperature (1,400 C) precipitation hardening was studied for three Y{sub 2}O{sub 3}-partially stabilized ZrO{sub 2} (Y-PSZ) two-phase single crystal alloys containing 3.4, 4.7 and 5.8 mol% Y{sub 2}O{sub 3} that had been annealed for up to 1,000 h at 1,600 C along both a ``soft`` [112] and a ``hard`` [001] specimen orientation. Crystals with high load-bearing ability, {>=}400 MPa, were found for all conditions; the flow stress for the strongest crystals at 1,400 C exceeded 700 MPa. The high strength is related to the fact that any 1/2 {l_angle}110{r_angle} matrix dislocation in the cubic ZrO{sub 2} matrix is a partial in two of the three tetragonal ZrO{sub 2} variants present within coherent precipitates, and that potent work hardening is present in this system. Age hardening is observed in crystals deformed along [112], whereas age softening is found for {l_angle}001{r_angle} crystals; this interesting difference arises from differences in dislocation-dislocation and dislocation-precipitate interactions in two orientations.
- OSTI ID:
- 72452
- Journal Information:
- Acta Metallurgica et Materialia, Journal Name: Acta Metallurgica et Materialia Journal Issue: 6 Vol. 43; ISSN 0956-7151; ISSN AMATEB
- Country of Publication:
- United States
- Language:
- English
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