On the Nature of the Growth of Bainitic α plates in Metastable β Ti Alloys

2007 ◽  
Vol 539-543 ◽  
pp. 3684-3689
Author(s):  
S.M.C. van Bohemen ◽  
Jilt Sietsma ◽  
Sybrand van der Zwaag
Keyword(s):  
Grain Boundaries ◽  
Optical Microscopy ◽  
Growth Mechanism ◽  
Electron Probe Microanalysis ◽  
Electron Probe ◽  
Morphological Transition ◽  
Ti Alloy ◽  
Lattice Structures ◽  
Transformation Mechanism ◽  
Ti Alloys

The growth mechanism of bainitic α plates in Ti-4.5Fe-6.8Mo-1.5Al, a metastable β Ti alloy, has been investigated by optical microscopy, electron probe microanalysis (EPMA) and dilatometry. The observations are compared with the transformation characteristics of primary α plates, which form at relatively high temperatures. The primary α plates form predominantly on β grain boundaries, whereas the bainitic α plates nucleate both at grain boundaries and intragranularly. It is shown that the morphological transition with decreasing temperature is associated with a change in transformation mechanism. The EPMA results show that the primary α plates are formed by a partitioning transformation. In contrast, the growth of the bainitic α plates is partitionless, followed by a post-transformation redistribution of Fe. This mechanism is similar to bainite in steel. The Fe diffusion from the supersaturated bainitic α plates to the β matrix causes the observed dilatation signal. The results of dilatometry in conjunction with optical microscopy indicate that a low misfit between the lattice structures exists, which is favourable for a partitionless transformation to occur at a low undercooling below T0.

Microstructure and Compound Developed from La-As-Fe System at 1223K

2013 ◽  
Vol 702 ◽  
pp. 145-148 ◽  
Author(s):  
Xiao Dong Liu ◽  
Jin Zhu Zhang ◽  
Si Si Zhu
Keyword(s):  
Optical Microscopy ◽  
Ternary Compound ◽  
Electron Probe Microanalysis ◽  
Electron Probe ◽  
Binary Compound ◽  
Atomic Ratio ◽  
X Ray Diffraction ◽  
Gray Phase ◽  
X Ray

The interaction among Lanthanum, Arsenic and Iron at 1223K were studied by means of electron probe microanalysis, optical microscopy and X-ray diffraction. The result shows that the gray phase might be a ternary compound La10Fe50As40, and the binary compound LaAs and the ternary compound La10Fe50As40 are the main interaction products when the atomic ratio of La to As is 1:3. The eutectic compound Fe2As can be precipitated from ferrite with the temperature decreasing.

Experimental Determination of Isothermal Section at 1050°C in the Fe-Nb-V Ternary System

2015 ◽  
Vol 757 ◽  
pp. 1-5
Author(s):  
Chang Jiang Liu ◽  
Qiu Juan Lv ◽  
Zhi Qing Guo ◽  
Yan Jiao Li ◽  
Jian Feng Guo
Keyword(s):  
Solid Solution ◽  
Isothermal Section ◽  
Ternary System ◽  
Phase Equilibria ◽  
Experimental Determination ◽  
Optical Microscopy ◽  
Electron Probe Microanalysis ◽  
Electron Probe ◽  
Microalloyed Steels

The phase equilibria in the Fe-Nb-V ternary system were investigated by means of optical microscopy, electron probe microanalysis. One isothermal section in the Fe-Nb-V ternary system at 1050 °C was firstly experimentally established. Present experimental results indicate that: (1) there is a large (Nb, V) continuous bcc solid solution; (2) there are the larger solubilities of V in the FeNb and Fe2Nb phases. The newly determined phase equilibria in this system will provide important support for the development of microalloyed steels.

Sn in the Ag-Hg Phase of Dental Amalgam

1988 ◽  
Vol 67 (10) ◽  
pp. 1275-1277 ◽  
Author(s):  
D.B. Mahler ◽  
J.D. Adey
Keyword(s):  
Grain Boundaries ◽  
Electron Probe Microanalysis ◽  
Electron Probe ◽  
Secondary Electron ◽  
Dental Amalgam ◽  
Final Conclusion

In a recent study, Sarkar and Eyer (1986) studied an amalgam which was formed using a unique procedure. Based on their results, they concluded that the solubility of Sn in the Ag-Hg (γ1) phase of dental amalgam was virtually nil (<0.25 wt%). This finding is contrary to the published results of other investigations. The purpose of the present study was to clarify these disparate findings. A low-copper dental amalgam was examined by electron probe microanalysis. This amalgam was selected because it exhibits unusually large γ1 grains (10 μm). Because the influence of the electron-analyzing beam can be completely contained within these large grains, grain boundaries or peripheral phases would not be excited, and a valid analysis of the γ 1 grains themselves could be made. The analyses showed significant Sn contents of 2.0-3.0 wt%. Analyses of areas which contained grain boundaries showed slight or no differences in Sn content compared with that for the grains alone. Furthermore, secondary electron scans of this dental amalgam failed to reveal the intergranular precipitates of Sn-Hg observed by Sarkar and Eyer (1986) in their amalgam. These different results can be explained by the fact that the unique amalgam investigated by Sarkar and Eyer does not exhibit the same diffusional patterns as does dental amalgam, and that the composition of the γ1 in the two amalgams is not the same. The final conclusion is that the Ag-Hg (γ1) phase in dental amalgam does indeed contain a significant amount of Sn.

Experimental Determination of Isothermal Section at 900°C in the Fe-Nb-V Ternary System

2013 ◽  
Vol 546 ◽  
pp. 107-111
Author(s):  
Chang Jiang Liu ◽  
Yan Jiao Li ◽  
Zhi Qing Guo ◽  
Qiu Juan Lv ◽  
Fang Xie ◽  
...  
Keyword(s):  
Solid Solution ◽  
Isothermal Section ◽  
Ternary System ◽  
Phase Equilibria ◽  
Experimental Determination ◽  
Optical Microscopy ◽  
Electron Probe Microanalysis ◽  
Electron Probe ◽  
Microalloyed Steels

The phase equilibria in the Fe-Nb-V ternary system were investigated by means of optical microscopy, electron probe microanalysis. One isothermal section in the Fe-Nb-V ternary system at 900 °C was firstly experimentally established. Present experimental results indicate that: (1) there is a large (Nb, V) continuous bcc solid solution; (2) there are the larger solubilities of V in the FeNb and Fe2Nb phases. The newly determined phase equilibria in this system will provide important support for the development of microalloyed steels.

Microstructure and Compound Developed from Ce-As-Fe System at High Temperature

2012 ◽  
Vol 460 ◽  
pp. 103-106
Author(s):  
Sheng Tao Dou ◽  
Jin Zhu Zhang ◽  
Jun Huang
Keyword(s):  
High Temperature ◽  
Optical Microscopy ◽  
Electron Probe Microanalysis ◽  
Electron Probe ◽  
Main Product ◽  
Binary Compound ◽  
Atomic Ratio ◽  
X Ray Diffraction ◽  
X Ray

The interaction among Cerium, Arsenic and Iron at high temperature in a pressure-tight reactor were studied by means of electron probe microanalysis, optical microscopy and X-ray diffraction to understand what compounds could be developed and how about their stability chemically should be. The result shows that the binary compound CeAs is the main product on condition that the atomic ratio of Cerium to Arsenic is 2:1. There are some Fe2Ce, Ce4As3 and Fe17Ce2 compounds developed meanwhile. The amount of Fe17Ce2 phase by the base of steel increased with time prolonging at high temperature

scholarly journals Fracture analysis of the circulating pump bolts

2020 ◽  
Vol 213 ◽  
pp. 02017
Author(s):  
Chengjun Jiang ◽  
Wei Wang ◽  
Xiaohui Zou ◽  
Jifeng Wang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Power Plant ◽  
Stress Corrosion ◽  
Optical Microscopy ◽  
Electron Probe Microanalysis ◽  
Electron Probe ◽  
Fracture Analysis ◽  
Chloride Ions ◽  
Scanning Electron

The microstructure, micrograph of the fracture sections and the alloy elements distribution of the fractured flange-connecting bolts of 3# circulating pump in a power plant were analyzed by the scanning electron microscopy, the optical microscopy and the electron probe microanalysis. The results showed that the failed bolts’ material is not the design material, and failure of the bolts is due to the stress corrosion crack propagation of the bolts’ austenitic material by chloride ions in seawater.

scholarly journals Development and synthesis of orthophosphate single crystals of YPO4 and LuP4 activated with Er3+

2021 ◽  
Vol 2103 (1) ◽  
pp. 012072
Author(s):  
E A Silantieva ◽  
M V Zamoryanskaya ◽  
B E Burakov
Keyword(s):  
Optical Microscopy ◽  
Single Crystals ◽  
Electron Probe Microanalysis ◽  
Electron Probe ◽  
X Ray Diffraction ◽  
Slow Cooling ◽  
X Ray

Abstract Crystals of xenotime-structured phosphates doped with erbium had been grown from molybdate flux at a temperature 1220 ° C followed by slow cooling. The crystals synthesized had been studied using X-ray diffraction and electron probe microanalysis in combination with optical microscopy and luminescence studies.

Corrosion of Monel 400 in High CO2 Well Water

CORROSION ◽  
1968 ◽  
Vol 24 (5) ◽  
pp. 134-136 ◽  
Author(s):  
GILBERT M. UGIANSKY ◽  
GEORGE A. ELLINGER
Keyword(s):  
Grain Boundaries ◽  
Electron Probe Microanalysis ◽  
Electron Probe ◽  
Pure Copper ◽  
Well Water ◽  
Second Phase ◽  
High Co2 ◽  
Monel 400

Abstract Dezincification type corrosion of a Monel Alloy well screen in water with 23–54ppm CO2 is discussed in detail. The second phase in the corroded grain boundaries was identified by electron probe microanalysis as nearly pure copper with little or no nickel. It is concluded that Monel may be susceptible to dezincification-type corrosion when used in certain environments.

Sign in / Sign up

Export Citation Format

Share Document