Phase relationships in the Ce–Nd–B system at 773 K

Author(s):  
Xuehong Cui ◽  
Jinming Zhu ◽  
Ketong Luo ◽  
Jianlie Liang

Abstract Phase relationships in the Ce-Nd-B ternary system at 773 K were investigated by means of X-ray diffraction and scanning electron microscopy with energy dispersive X-ray spectroscopy techniques. Six borides, i. e. CeB4, CeB6, NdB4, NdB6, NdB66 and Nd2B5 are confirmed in this work. No ternary compound was observed. CeB4 and NdB4 were discovered to form the continuous solid solution phase (Ce,Nd)B4, CeB6 and NdB6 also form the solid solution phase (Ce,Nd)B6. The maximum solid solubility of Ce in (Ce,Nd)2B5 phase is 46.5 at.%. The isothermal section of the Ce-Nd-B ternary system at 773 K consists of 3 three-phase regions, 7 two-phase regions and 7 single- phase regions.

2011 ◽  
Vol 704-705 ◽  
pp. 475-479
Author(s):  
Shun Kang Pan ◽  
Rui Yan ◽  
Huai Ying Zhou ◽  
Li Chun Cheng ◽  
Qing Rong Yao ◽  
...  

The isothermal section of the phase diagram of the ternary system Y–Fe–V at 773 K was investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersion spectroscopy (EDS) techniques. It consists of 9 single-phase regions, 16 two-phase regions and 8 three-phase regions. The ternary compound YFe12-xVx (1.5≤x≤2.7, space group I4/mmm) with Mn12Th-type structure was confirmed in this system. At 773 K, the maximum solid solubility of V in Fe, and YFe2, is about 23 at.%, and 3 at.%, respectively, Fe in V is about 22 at.%. And that of Y in Fe, FeV and V don′t exceed 1 at.%.


Author(s):  
Ketong Luo ◽  
Jianlie Liang ◽  
Jinming Zhu ◽  
Xuehong Cui

Abstract The Fe-rich corner of the Ce–Nd–B–Fe quaternary system at 773 K has been experimentally investigated by means of X-ray powder diffraction and scanning electron microscopy equipped with energy dispersive X-ray spectroscopy techniques. No quaternary compound was observed in this system. Ce2Fe14B and Nd2Fe14B were found to form the continuous solid solution (Ce,Nd)2Fe14B. Ce-Fe4B4 and NdFe4B4 also form the solid solution (Ce,Nd)-Fe4B4. The isothermal section consists of 8 three-phase regions and 2 four-phase regions.


2013 ◽  
Vol 747-748 ◽  
pp. 765-771 ◽  
Author(s):  
Jian Sheng Yao ◽  
Ding Zhong Tang ◽  
Xiao Guang Liu ◽  
Cheng Bo Xiao ◽  
Xin Li ◽  
...  

The interfacial reactions between ceramic moulds and DZ417G and DZ125 superalloys were investigated. The microstructure and composition of the interface region were observed by optical microscope, X-ray diffraction and scanning electron microscope with energy dispersive spectroscopy. The results showed that (Al1-xCrx)2O3solid solution phase with pink color was formed from the dissolution of Cr2O3and Al2O3and vapour phase, which was transferred to the reaction surfaces. The reaction layer thicknesses of DZ417G and DZ125 alloys were about in the range of 40-50μm. The interface reaction product between DZ417G alloy and ceramic mould was TiO2and the product between DZ125 alloy and ceramic mould was HfO2.


2008 ◽  
Vol 104 (11) ◽  
pp. 113527 ◽  
Author(s):  
L. Alves ◽  
T. P. A. Hase ◽  
M. R. C. Hunt ◽  
A. C. Brieva ◽  
L. Šiller

2007 ◽  
Vol 280-283 ◽  
pp. 1441-1444 ◽  
Author(s):  
Qiang Xu ◽  
Xing Hong Zhang ◽  
Jie Cai Han ◽  
Xiao Dong He

Large-scale (Ti,Cr)B2-Cu composite from Ti, Cr, B and Cu powders was produced by combining combustion synthesis with Pseudo Hot Isostatic Pressing. The diameter of the synthesized product is 240 millimeter. The product was identified using X-ray diffraction and the result showed that only (Ti,Cr)B2 and Cu phases, without other phases, existed in the product. The analysis of the microstructure indicated that the skeletal structure had been formed in the (Ti,Cr)B2 solid solution phase. Fine (Ti,Cr)B2 reinforcement grew in near equivalent axis-like shape and some sintering neckings were found between the solid solution phases. The relative density of the synthesized product was 93.6% because the skeletal structure baffled the densification of the composite. The bending strength and fracture toughness of the product were 476 MPa and 6.8 MPa·m1/2 respectively.


1987 ◽  
Vol 99 ◽  
Author(s):  
C. Y. Yang ◽  
S. M. Heald ◽  
J. J. Reilly ◽  
M. Suenaga

ABSTRACTWe have examined the role of H on the superconductivity properties, the atomic structure, and the electronic state in the HxYBa2Cu3O7. The hydrogen solid solution phase (up to ×≃O.2) exhibits a superconducting transition at 94 K, which was usually slightly higher than the starting oxide (YBa2Cu3O7, while the hydride phases (H rich) are not superconducting. Infrared (IR), x-ray diffraction, and x-ray absorption spectroscopy (XAS) measurements indicate that H is located interstitially only near Cu sites.


Metals ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 958 ◽  
Author(s):  
Cuiping Wang ◽  
Xianjie Zhang ◽  
Lingling Li ◽  
Yunwei Pan ◽  
Yuechao Chen ◽  
...  

The phase equilibria of the Co-Ti-Ta ternary system at 1000 °C, 1100 °C, and 1200 °C were experimentally investigated using an electron probe microanalyzer and X-ray diffraction. Experimental results show that: (1) No ternary compound exists in the studied isothermal sections; (2) the β(Ti) and β(Ta) phases form the continuous solid solution β(Ti,Ta) in the Ti-Ta side; (3) the solubility of Ta in the (αCo) is less than 5%; (4) the phases of Co2Ti(h) and γ-Co2Ta, Co2Ti(c) and β-Co2Ta form the continuous solid solutions Co2(Ta,Ti)(h) and Co2(Ta,Ti)(c), respectively.


Author(s):  
R.W. Carpenter ◽  
Changhai Li ◽  
David J. Smith

Binary Nb-Hf alloys exhibit a wide bcc solid solution phase field at temperatures above the Hfα→ß transition (2023K) and a two phase bcc+hcp field at lower temperatures. The β solvus exhibits a small slope above about 1500K, suggesting the possible existence of a miscibility gap. An earlier investigation showed that two morphological forms of precipitate occur during the bcc→hcp transformation. The equilibrium morphology is rod-type with axes along <113> bcc. The crystallographic habit of the rod precipitate follows the Burgers relations: {110}||{0001}, <112> || <1010>. The earlier metastable form, transition α, occurs as thin discs with {100} habit. The {100} discs induce large strains in the matrix. Selected area diffraction examination of regions ∼2 microns in diameter containing many disc precipitates showed that, a diffuse intensity distribution whose symmetry resembled the distribution of equilibrium α Bragg spots was associated with the disc precipitate.


2016 ◽  
Vol 873 ◽  
pp. 18-22
Author(s):  
Ming Li Huang ◽  
Xue Shen ◽  
Hong Xiao Li

The equilibrium alloys closed to Mg-Nd side in the Mg-rich corner of the Mg-Zn-Nd system at 400°C have been investigated by scanning electron microscopy, electron probe microanalysis and X-ray diffraction. The binary solid solutions Mg12Nd and Mg3Nd with the solubility of Zn have been identified. The maximum solubility of Zn in Mg12Nd is 4.8at%, and Mg12Nd phase can be in equilibrium with Mg solid solution. However, only when the solubility range of Zn in 26at%~32.2at%, Mg3Nd can be in two-phase equilibrium with Mg solid solution. As the results, two two-phase regions as Mg+Mg12Nd and Mg+Mg3Nd and a three-phase region as Mg+Mg12Nd+Mg3Nd in Mg-Nd-Zn ternary isothermal section at 400°C have been identified.


1985 ◽  
Vol 49 (353) ◽  
pp. 547-554 ◽  
Author(s):  
M. Shahmiri ◽  
S. Murphy ◽  
D. J. Vaughan

AbstractThe crystal structure and compositional limits of the ternary compound Pt2FeCu (tulameenite), formed either by quenching from above the critical temperature of 1178°C or by slow cooling, have been investigated using X-ray diffraction, transmission electron microscopy, differential thermal analysis and electron probe microanalysis.The crystal structure of Pt2FeCu, established using electron density maps constructed from the measured and calculated intensities of X-ray diffraction patterns of powdered specimens, has the (000) and (½½0) lattice sites occupied by Pt atoms and the (½0½) and (0½½) sites occupied by either Cu or Fe atoms in a random manner. The resulting face-centred tetragonal structure undergoes a disordering transformation at the critical temperature to a postulated non-quenchable face-centred cubic structure. Stresses on quenching, arising from the ordering reaction, are relieved by twinning along {101} planes or by recrystallization along with deformation twinning; always involving grain boundary fracturing.Phase relations in the system Pt-Fe-Cu have been investigated through the construction of isothermal sections at 1000 and 600°C. At 1000°C there is an extensive single phase region of solid solution around Pt2FeCu and extending to the binary composition PtFe. At 600°C the composition Pt2FeCu lies just outside this now reduced area of solid solution in a two-phase field. Comparison of the experimental results with data for tulameenite suggests that some observed compositions may be metastably preserved. The occurrence of fine veinlets of silicate or other gangue minerals in tulameenite is suggested to result from grain boundary fracturing on cooling below the critical temperature of 1178°C and to be evidence of a magmatic origin.


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