Title

High Temperature Tensile Deformation Behavior of New Heat Resistant Aluminum Alloy

Authors

Authors

S. H. Choi; S. Y. Sung; H. J. Choi; Y. H. Sohn; B. S. Han;K. A. Lee

Comments

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Abbreviated Journal Title

Mater. Trans.

Keywords

heat-resistant aluminum alloy; high temperature tensile; deformation; behavior; (nickel, cobalt)(3)Al-4; strengthening phase; COOLING RATE; FATIGUE; DUCTILITY; Materials Science, Multidisciplinary; Metallurgy & Metallurgical; Engineering

Abstract

This study attempted to investigate the high temperature tensile deformation behaviour of new Al-1%Mg-1.1%Si-0.8%CoNi heat resistant aluminium alloy. New aluminium alloy strengthened by Co-Ni based phase was manufactured by using powder ball milling and continuous casting, based on the alloy design & preliminary test. High temperature tensile tests were conducted at various temperatures from 298 K to 723 K. OM, SEM, EPMA, XRD, FIB and HR-TEM equipments were used to analyse microstructure, phases, and fracture surface. Microstructure of the new alloy mainly consisted of Al matrix and Co-Ni based phases (1 similar to 8 mu m). The Co-Ni based phase was analyzed and confirmed as (Ni, Co)(3)Al-4 having incoherent interface with matrix. In high temperature tensile results, the new aluminium alloy didn't show significant decrease (19.6%) of strength with increasing temperature (723 K), suggesting totally different behaviour vis-a-vis conventional A319 alloy (87.0% decrease of T.S.). Fractography observation results of new alloy represented the ductile fracture mode with dimples. Voids were mainly initiated at Co-Ni based strengthening phases. It was apparently observed that the strengthening effect of the (Ni, Co)(3)Al-4 could be still maintained at high temperature of 723 K. The deformation mechanism of this alloy was also discussed. [doi:10.2320/matertrans.M2011025]

Journal Title

Materials Transactions

Volume

52

Issue/Number

8

Publication Date

1-1-2011

Document Type

Article

Language

English

First Page

1661

Last Page

1666

WOS Identifier

WOS:000295711700027

ISSN

1345-9678

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