Formation of dispersions of rare earth oxides in titanium alloys using rapid solidification processing

Technical Report · Sun Jan 01 00:00:00 EST 1984

OSTI ID:6924586

Konitzer, D G

Rapid solidification processing (RSP) was used to produce extended solid solutions of rare earth elements and O in Ti and some of its alloys. RSP was affected by laser surface melting and the resulting microstructures characterized using analytical TEM. Heat treatment, typically 10 h at 1000/sup 0/K, results in the formation of an ultrafine dispersion of rare earth oxides. In the case of Er/sub 2/O/sub 3/, the particles are 8 to 20 nm in diameter with a mean interparticle spacing of 120 nm. The point and space groups of these precipitates are consistent with these being m3 and Ia3, respectively, which are identical with those of the rare earth oxides Y/sub 2/O/sub 3/, Er/sub 2/O/sub 3/. The orientation relationships (OR) exhibited by these oxide particles were studied. The coarsening equations, modified for Er/sub 2/O/sub 3/ particles in a Ti matrix, have been used to predict the coarsening behavior of the dispersions produced in this work. If the composition of the alloy contains an excess amount of Er, the particles exhibit remarkable stability up to the ..beta..-transus. Above this temperature, the coarsening rate increases markedly. For a slight excess of O, the stability of the particles is extremely improved up to above 1200/sup 0/K. In a specimen tested to failure, there was a marked increase in mechanical strength.

• Research Organization: Illinois Univ., Urbana (USA)
• DOE Contract Number: AC02-76ER01198
• OSTI ID: 6924586
• Report Number(s): DOE/ER/01198-1407; ON: DE84008664
• Resource Relation: Other Information: Portions are illegible in microfiche products. Thesis
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
TITANIUM ALLOYS
DISPERSION HARDENING
ERBIUM OXIDES
LASER-RADIATION HEATING
MECHANICAL PROPERTIES
ORIENTATION
PARTICLES
SOLID SOLUTIONS
SOLIDIFICATION
YTTRIUM OXIDES
ALLOYS
CHALCOGENIDES
DISPERSIONS
ERBIUM COMPOUNDS
HARDENING
HEATING
MIXTURES
OXIDES
OXYGEN COMPOUNDS
PHASE TRANSFORMATIONS
PLASMA HEATING
RARE EARTH COMPOUNDS
SOLUTIONS
TRANSITION ELEMENT COMPOUNDS
YTTRIUM COMPOUNDS
360100* - Metals & Alloys