Bimodal size distributions of {gamma}{prime} precipitates in {und Ni}-Al-Mo. 2: Transmission electron microscopy

Journal Article · Fri Sep 01 04:00:00 EDT 1995 · Acta Metallurgica et Materialia

DOI:https://doi.org/10.1016/0956-7151(95)00044-V· OSTI ID:105988

Sequeira, A D; Calderon, H A; Kostorz, G ^[1]; Pedersen, J S ^[2]

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1. ETH Zuerich (Switzerland). Institut fuer Angewandte Physik
2. Risoe National Lab., Roskilde (Denmark). Dept. of Solid State Physics

A double step aging procedure was used to produce bimodal size distributions of precipitates in two {und Ni}-Al-Mo alloys. The evolution of the microstructure during the decomposition was studied using transmission electron microscopy. Shape and changes in the spatial correlations of the precipitate ensemble as well as precipitate size distributions were determined for a very wide times scale. Particle shape transitions during aging were monitored by the determination of aspect-ratio distributions. The results is found between the size distributions determined by the two techniques. In the alloy with high coherency strains peculiar phenomena were observed during aging, e.g. coalescence among the small precipitates, preferential growth of small precipitates in the presence of larger ones, and a dramatic narrowing of the size distribution of large precipitates indicating a uniformization in size towards late stages of aging.

• OSTI ID: 105988
• Journal Information: Acta Metallurgica et Materialia, Journal Name: Acta Metallurgica et Materialia Journal Issue: 9 Vol. 43; ISSN 0956-7151; ISSN AMATEB
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
AGING
ALUMINIUM ALLOYS
ASPECT RATIO
MICROSTRUCTURE
MOLYBDENUM ALLOYS
NICKEL BASE ALLOYS
PARTICLE SIZE
PARTICLES
PRECIPITATION
SAMPLE PREPARATION
SHAPE
SMALL ANGLE SCATTERING
TIME DEPENDENCE