Unidirectional Solidification of a Nbss/Nb5Si3 In-Situ Composite

X.P. Guo; Ping Guan; X. Ding; Jun Zhang; K. Kusabiraki; Heng Zhi Fu

doi:10.4028/www.scientific.net/MSF.475-479.745

Paper Titles

Growth of Single Crystals and Low Temperature Oxidation Behaviors of MoSi₂ and NbSi₂
p.729

Microstructure and Properties of Directionally Solidified NbSi₂/ Nb₅Si₃ Composites
p.733

Microstructures and Properties of Refractory Niobium-Silicide-Based Composites
p.737

Oxidation Resistant Silicide Coatings for Nb_ss/Nb₅Si₃ In-Situ Composites
p.741

Unidirectional Solidification of a Nb_ss/Nb₅Si₃ In-Situ Composite
p.745

Preparation of Nanocrystalline NiAl Compounds and Composites by Mechanical Alloying
p.749

Catalytic Properties of Ni₃Al for Hydrogen Production Reactions
p.755

Mechanical Anisotropy of NiAl Alloys Processed by Hot Hydrostatic Extrusion
p.759

Tensile Creep Behavior of NiAl-9Mo Eutectic Alloy
p.763

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Unidirectional Solidification of a Nb_ss/Nb₅Si₃ In-Situ Composite

Abstract:

The directionally solidified specimens of Nb-13.52 Si-22.60 Ti–6.88 Hf–2.54 Cr–2.24 Al alloy were prepared in an electron beam floating zone melting furnace at the withdrawing rate of 0.1, 0.3, 0.6, 1.0, 2.4 and 6.0 mm/min. All the primary Nb solid solution (Nbss) columns, Nbss + (Nb)3Si/(Nb)5Si3 eutectic colonies and divorced (Nb)3Si/(Nb)5Si3 plates or chains align well along the longitudinal axis of the specimens. With increasing of the withdrawing rate, the microstructure is gradually refined, and the amount of Nbss + (Nb)3Si/(Nb)5Si3 eutectic colonies increases. Both the room temperature ultimate tensile strength σb and fracture toughness KQ are improved for the directionally solidified specimens. The tensile fracture occurs in a cleavage way.