Preparation and microstructure evolution of directionally solidified Al2O3/YAG/YSZ ternary eutectic ceramics by a modified electron beam floating zone melting

2013 ◽  
Vol 91 ◽  
pp. 92-95 ◽  
Author(s):  
Haijun Su ◽  
Jun Zhang ◽  
Lin Liu ◽  
Hengzhi Fu
Keyword(s):  
Electron Beam ◽  
Microstructure Evolution ◽  
Ternary Eutectic ◽  
Zone Melting ◽  
Floating Zone ◽  
Directionally Solidified

Microstructure and Mechanical Properties of an Advanced Niobium Based Ultrahigh Temperature Alloy

2007 ◽  
Vol 539-543 ◽  
pp. 3690-3695 ◽  
Author(s):  
X.P. Guo ◽  
L.M. Gao ◽  
Ping Guan ◽  
K. Kusabiraki ◽  
Heng Zhi Fu
Keyword(s):  
Mechanical Properties ◽  
Electron Beam ◽  
Directional Solidification ◽  
Room Temperature ◽  
Zone Melting ◽  
Floating Zone ◽  
Directionally Solidified ◽  
Microstructure And Mechanical Properties ◽  
Temperature Fracture ◽  
Ultrahigh Temperature

The microstructure and mechanical properties including room temperature fracture toughness Kq, tensile strengthσb and elongationδ at 1250°C of the Nb based alloy directionally solidified in an electron beam floating zone melting (EBFZM) furnace have been evaluated. The microstructure is primarily composed of Nb solid solution (Nbss), α-(Nb)5Si3 and (Nb)3Si phases. After directional solidification with the moving rate of electron beam gun R being respectively 2.4, 4.8 and 7.2 mm/min, the primary Nbss dendrites, Nbss + (Nb)5Si3/(Nb)3Si eutectic colonies (lamellar or rod-like) and divorced Nb silicide plates align along the longitudinal axes of the specimens. When R = 2.4 mm/min, the best directional microstructure is obtained. Directional solidification has significantly improved theσb at 1250°C and Kq. The maximumσb occurs for the specimens with R = 2.4 mm/min and is about 85.0 MPa, meanwhile, the Kq is about 19.4 MPam1/2.

Numerical and experimental study of electron beam floating zone melting of Iridium single crystal

2017 ◽  
Vol 250 ◽  
pp. 239-246 ◽  
Author(s):  
Jieren Yang ◽  
Hu Wang ◽  
Binqiang Wang ◽  
Rui Hu ◽  
Yi Liu ◽  
...  
Keyword(s):  
Experimental Study ◽  
Electron Beam ◽  
Single Crystal ◽  
Zone Melting ◽  
Floating Zone ◽  
Iridium Single Crystal

Effect of growth rate on microstructure and microstructure evolution of directionally solidified Nb-Si alloys

2008 ◽  
Vol 1128 ◽  
Author(s):  
Yoshihito Sekito ◽  
Seiji Miura ◽  
Kenji Ohkubo ◽  
Tetsuo Mohri ◽  
Norihito Sakaguchi ◽  
...  
Keyword(s):  
Growth Rate ◽  
Orientation Relationship ◽  
Microstructure Evolution ◽  
Crystallographic Orientation ◽  
Floating Zone ◽  
Directionally Solidified ◽  
Solidification Direction ◽  
Arc Melting ◽  
Heat Treated ◽  
Crystallographic Orientation Relationship

AbstractIn the present work, Nb-18.1Si-1.5Zr alloy rods are produced with a growth rate ranging from 1.5 to about 1500 mm/h using the optical floating zone (OFZ) furnace. A part of each specimen is heat-treated at 1650 oC for 100 h. The microstructure was observed using SEM and TEM and analyzed using EPMA and EBSD.Eutectic-cells are observed in as-grown specimens with a growth rate of 150 mm/h or higher. It is found by EBSD analysis that the solidification direction of Nb is along <113> and that of Nb3Si is along <001], and {112} of Nb and {110) of Nb3Si are parallel. The present crystallographic orientation relationship between Nb and Nb3Si is different from that found in previous reports by several researchers. It was also confirmed that the heat-treated microstructure in the specimen grown by OFZ with a growth rate of 150 mm/h is similar to that in the heattreated specimen prepared by arc-melting.

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