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Indexed by:期刊论文

Date of Publication:2010-02-04

Journal:JOURNAL OF ALLOYS AND COMPOUNDS

Included Journals:SCIE、EI、Scopus

Volume:490

Issue:1-2

Page Number:L1-L4

ISSN No.:0925-8388

Key Words:Metal and alloy; Microstructure; Mechanical properties; Hardness

Abstract:The maximum undercooling up to 550 K was achieved in the bulk eutectic Ni78.6Si21.4 alloy melt through glass fluxing, which was combined with cyclic superheating. Transmission electron microscope (TEM), scanning electron microscope (SEM) and optical microscopy techniques were adopted to investigate the microstructure, and identified the phase composition. The directional growth, quasi-regular and refined microcrystalline microstructures were achieved in the as-solidified structure with the increased undercooling. With the increase of undercooling, the relationship between the microstructure and the hardness including the size effect of crystal grain were systematically investigated. The experimental results show that directional growth, quasi-regular and refined microstructure produced large strengthening effect, and improved the hardness to 56.5 on the Rockwell hardness C (HRC) scale. The fact is also proved by the Vickers hardness. (c) 2009 Elsevier B.V. All rights reserved.