The positron annihilation and Hall-Petch relation in polycrystalline Fe[sub 78]B[sub 13]Si[sub 9] alloys with ultrafine grains

Journal Article · Sat May 01 00:00:00 EDT 1993 · Scripta Metallurgica et Materialia; (United States)

DOI:https://doi.org/10.1016/0956-716X(93)90018-N· OSTI ID:6521487

Ding, B Z; Tong, H Y; Jiang, H G; Wang, J T; Wei, W D ^[1]

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1. Inst. of Metal Research, Shenyang (China)

Nanometer-sized crystalline materials, which are sometimes called nanocrystalline materials', have been reported to exhibit different properties from ordinary crystalline materials. The possibility of affecting the physical or mechanical properties of materials by producing nanocrystalline structures constitutes a major subject of interest in materials science. The positron annihilation and the Hall-Petch behaviors in the nanocrystalline FeBSi alloy prepared using the crystallization method were studied. The results indicate that because of the unusual nature of its grain boundaries (existing a great amount of defects) the nanocrystalline FeBSi alloy has higher values of microhardness than those of coarse grained crystalline and amorphous FeBSi alloys with the same composition. Hardness increases with the reduction of grain size in the nanocrystalline FeBSi alloys, i.e. the normal Hall-Petch relationship was obtained. The variation of interface characteristics with the grain size will strongly influence structure-sensitive properties, such as H[sub v]. From the present results, a very good overall agreement between the trends of the mean lifetime value [bar [tau]] and Vickers microhardness value H[sub v] can be obtained.

• OSTI ID: 6521487
• Journal Information: Scripta Metallurgica et Materialia; (United States), Vol. 28:9; ISSN 0956-716X
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
BORON ALLOYS
CRYSTAL DEFECTS
MICROHARDNESS
IRON BASE ALLOYS
SILICON ALLOYS
ANNIHILATION
GRAIN BOUNDARIES
GRAIN SIZE
POSITRONS
VICKERS HARDNESS
ALLOYS
ANTILEPTONS
ANTIMATTER
ANTIPARTICLES
BASIC INTERACTIONS
CRYSTAL STRUCTURE
ELECTROMAGNETIC INTERACTIONS
ELEMENTARY PARTICLES
FERMIONS
HARDNESS
INTERACTIONS
IRON ALLOYS
LEPTONS
MATTER
MECHANICAL PROPERTIES
MICROSTRUCTURE
PARTICLE INTERACTIONS
SIZE
360102* - Metals & Alloys- Structure & Phase Studies
360103 - Metals & Alloys- Mechanical Properties
665100 - Nuclear Techniques in Condensed Matter Physics - (1992-)