Effect of Isothermal Forging on Microstructures and Mechanical Properties of Nb-Si In Situ Composite

2007 ◽  
Vol 561-565 ◽  
pp. 423-426 ◽  
Author(s):  
Yong Wang Kang ◽  
Shi Yu Qu ◽  
Ya Fang Han ◽  
Ji Xia Song ◽  
Ding Zhong Tang
Keyword(s):  
Solid Solution ◽  
High Temperature ◽  
Nominal Composition ◽  
Temperature Structure ◽  
X Ray Diffraction ◽  
In Situ Composite ◽  
Large Size ◽  
Directional Texture ◽  
Niobium Solid Solution

Nb-Si based in-situ composites have great potential for the application of high temperature structure components. In this paper, the influence of microstructure on the compression behavior of Nb-Si in-situ composite forged at high temperature was studied. The alloy with nominal composition of Nb-12Si-24Ti-4Cr-4Al-2Hf was consumable arc-melted, and then isothermal forged at 960°C. Scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS) and X-ray diffraction (XRD) were used to characterize the microstructure, composition and phases. The compressive behaviors at 1250°C were carried out by Gleeble thermo-mechanical simulator. The results showed that the microstructures were inhomogenous in the different sections of the ingot, and no evident directional texture formed, and the main phases were niobium solid solution, Nb5Si3 and Ti5Si3. However, no macro-elements segregation in the ingot was observed. The compression strength was in the range of 140-360MPa. BSE observation showed that irregular-shaped Nb5Si3 and Ti5Si3 phases distributed in Nb solid solution and the size of Nb5Si3 in three tested samples was 10μm. Large size of eutectoid texture existed in the sample with strength of ~140MPa. On the contrary, in the sample with higher strength of 360MPa, eutectoid structures were hardly detected. The results suggested that the strength decreased gradually with size increase of eutectoid structure.

High temperature X-ray diffraction study of phase decomposition in rapidly quenched Al–Ge–Si

1999 ◽  
Vol 14 (2) ◽  
pp. 118-121
Author(s):  
N. Mattern ◽  
A. Teresiak ◽  
T. Schubert ◽  
W. Löser ◽  
S. Doyle
Keyword(s):  
Solid Solution ◽  
High Temperature ◽  
Synchrotron Radiation ◽  
Systematic Change ◽  
Phase Decomposition ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ge Matrix ◽  
Al Matrix

The phase decomposition occurring during the heating of rapidly quenched Al–Ge–Si alloys has been investigated in situ by means of synchrotron radiation X-ray diffraction. The metastable Al–Ge phases formed in the as-quenched state transform during heating to Al and Ge. The addition of silicon decreases the transformation temperature. A Ge(Si) solid solution is indicated by a systematic change in the lattice constant of Ge as a result of the diffusion of Si from the Al matrix into the phase-separated Ge matrix.

scholarly journals In-Situ X-ray Diffraction Measurement for Pure Niobium Metal in High Temperature Hydrogen Atmosphere

2006 ◽  
Vol 70 (6) ◽  
pp. 467-472 ◽  
Author(s):  
Tomonori Nambu ◽  
Nobue Shimizu ◽  
Hisakazu Ezaki ◽  
Hiroshi Yukawa ◽  
Masahiko Morinaga ◽  
...  
Keyword(s):  
High Temperature ◽  
Hydrogen Atmosphere ◽  
Diffraction Measurement ◽  
X Ray Diffraction ◽  
X Ray ◽  
Pure Niobium

The application of the in situ high-temperature X-ray diffraction quantitative analysis

2008 ◽  
Vol 452 (2) ◽  
pp. 446-450 ◽  
Author(s):  
Qiuguo Xiao ◽  
Ling Huang ◽  
Hui Ma ◽  
Xinhua Zhao
Keyword(s):  
High Temperature ◽  
Quantitative Analysis ◽  
X Ray Diffraction ◽  
X Ray
Sign in / Sign up

Export Citation Format

Share Document