Effects of addition of magnesium on interface structure and high-strain-rate superplasticity in Si3N4-reinforced Al-alloy composites
1998; Elsevier BV; Volume: 46; Issue: 17 Linguagem: Inglês
10.1016/s1359-6454(98)00282-1
ISSN1873-2453
AutoresHyeon-Cheol Jeong, K. Hiraga, Mamoru Mabuchi, Kenji Higashi,
Tópico(s)Microstructure and mechanical properties
ResumoAbstract The mechanical properties and interface structure of fine-grained Al–Cu alloy and Al–Cu–Mg alloy composites, reinforced with Si 3 N 4 whiskers (Si 3 N 4 w) and particles (Si 3 N 4 p), are investigated to reveal the role of magnesium addition in high-strain-rate superplasticity. The Al–Cu alloy composites, which exhibit lower elongations ( 3 N 4 crystals without any interfacial reaction. On the other hand, the interfaces in the Al–Cu–Mg alloy composites, which exhibit high elongations (>280%), show strong reaction between the Al-matrix and Si 3 N 4 crystals. The result suggests that the addition of magnesium causes the reaction between the Al-matrix and Si 3 N 4 crystals, and consequently that partially melting of the reaction phases at the tensile-testing temperature results in the relaxation of stress concentration and suppresses the development of microcracks and cavities at the interfaces during superplastic deformation.
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