Influence of High Temperature Annealing on Microstructure Evolution of Ni-24Fe-14Cr-8Mo Superalloy

2021 ◽  
Vol 904 ◽  
pp. 117-123
Author(s):  
Yi Cui ◽  
Yun Fei Zhang ◽  
Yan Guang Han ◽  
Da Lv

The effect of high temperature annealing on microstructure evolution of Ni-24Fe-14Cr-8Mo alloy was investigated through Optical Microscopy (OM), Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD) and Rockwell Hardness Testing Machine. Three kinds of grain growth patterns were found at different annealing temperatures due to carbides precipitation and dissolution. After a combination of high temperature annealing and aging treatment, the hardness versus time curves performed a parabolic pattern. The highest hardness was achieved under 1070°C/60 minutes treatment, and the desirable annealing time should be 60 minutes to 90 minutes.

2015 ◽  
Vol 8 (1) ◽  
pp. 1472-1477
Author(s):  
KETAN BHAT ◽  
Maneesh Avadhani ◽  
Milind Gurav ◽  
Vadiraj Patil ◽  
M. Krishna

The objective of the work was to evaluate contact fatigue and operating performance of electrodeposited Ni-WC composite coated gears using experimental technique. The electrodeposited Ni-WC coating was characterized for coating thickness, hardness and crystal structure using Electro-Physik gauge, Rockwell Hardness testing machine and X-Ray Diffraction respectively. The operation condition was estimated using designed test rig and vibration pick with CRO. The results show that coated gears are smoother in operation and offer more resistance to wear and fretting due to increased hardness.


2020 ◽  
Vol 28 ◽  
pp. 14-19
Author(s):  
Zamir V. Shomakhov ◽  
Akhmed M. Karmokov ◽  
Oleg A. Molokanov ◽  
Olga O. Molokanova ◽  
Rita Y. Karmokova ◽  
...  

Studies of the temperature dependence of the electrical properties of glasses show that the high-temperature annealing in glasses observed irreversible processes. These processes lead to changes in electrical conductivity, dielectric permittivity, and hence the electrical capacitance, dielectric loss tangent, and other parameters. Obviously, this is due to structural changes in the glass as a result of high-temperature annealing. In this regard, this paper presents studies of structural and phase transformations in glasses used for the production of microchannel plates in the process of high-temperature annealing in vacuum and in the air atmosphere at different times. The studies were conducted by x-ray phase and X-ray diffraction analysis, as well as X-ray fluorescence elemental analysis.


2006 ◽  
Vol 514-516 ◽  
pp. 18-22
Author(s):  
Shibin Zhang ◽  
Z. Hu ◽  
Leandro Raniero ◽  
X. Liao ◽  
Isabel Ferreira ◽  
...  

A series of amorphous silicon carbide films were prepared by plasma enhanced chemical vapor deposition technique on (100) silicon wafers by using methane, silane, and hydrogen as reactive resources. A very thin (around 15 Å) gold film was evaporated on the half area of the a- SiC:H films to investigate the metal induced crystallization effect. Then the a-SiC:H films were annealed at 1100 0C for 1 hour in the nitrogen atmosphere. Fourier transform infrared spectroscopy (FTIR), X-Ray diffraction (XRD), and scanning electron microscopy (SEM) were employed to analyze the microstructure, composition and surface morphology of the films. The influences of the high temperature annealing on the microstructure of a-SiC:H film and the metal induced metallization were investigated.


1996 ◽  
Vol 11 (5) ◽  
pp. 1133-1136 ◽  
Author(s):  
Mohindar S. Seehra ◽  
V. Suresh Babu

X-ray diffraction and temperature dependent (5 K–380 K) magnetic measurements have been carried out in INCONEL 718 superalloy before and after high temperature aging treatments. (INCONEL is a trademark of the INCO family of companies.) The nominal composition of this alloy is Ni (52.5%), Cr (19.0%), Fe (18.5%), Nb (5.1%), Mo (3.0%), Ti (0.9%), Al (0.5%), Cu (0.15%), and C (0.08%), and it yields an x-ray diffraction pattern consisting of a fcc phase with α = 3.5987 (3) Å and an orthorhombic phase associated with δ-Ni3Nb. It is concluded that the fcc pattern is due to both the γ austenitic phase and γ′ Ni3(Al, Ti) phase of alloy 718. The standard annealing and aging treatment carried out in air at temperatures between 621 and 982 °C produces surface oxides (Cr, Fe)2O3 and FeNbO4 (which are easily removed by etching and polishing) and contracts the lattice. Magnetic measurements show a distinct phase transition at Tc = 14 K, which has been attributed to the γ′-Ni3(Al, Ti) phase by the process of elimination and by observing that it has most of the characteristics of the weak itinerant ferromagnet Ni74.5Al25.5. This transition may have some effects on the cryogenic applications of this alloy.


2012 ◽  
Vol 725 ◽  
pp. 273-276
Author(s):  
Motoki Takahara ◽  
Suguru Funasaki ◽  
Jyun Kudou ◽  
Isao Tsunoda ◽  
Kenichiro Takakura ◽  
...  

For the purpose of improving the crystalline quality of undoped and Si doped β-Ga2O3 films, high temperature annealing at 900°C was performed. The crystalline quality of the films investigated using scanning electron microscopy and X-ray diffraction. Also the conductivity of the films is compared before and after the annealing. After the 900°C annealing, the XRD peaks intensity corresponding to β-Ga2O3 is increased. This result indicates that the crystalline quality improves by the high temperature annealing.


2002 ◽  
Vol 743 ◽  
Author(s):  
A. Piotrowska ◽  
E. Kaminska ◽  
A. Barcz ◽  
K. Golaszewska ◽  
H. Wrzesinska ◽  
...  

ABSTRACTWe have studied thermal stability of Nb and NbN contacts to GaAs and GaN by x-ray diffraction and SIMS, and demonstrated their excellent behaviour under high temperature annealing. GaAs/Nb and GaAs/NbN contacts are stable up to 800°C and 900°C, respectively while GaN/NbN and GaN/Nb/NbN remain stable up to 1000°C.


2007 ◽  
Vol 2007 (suppl_26) ◽  
pp. 369-374 ◽  
Author(s):  
D. Garipoli ◽  
P. Bergese ◽  
E. Bontempi ◽  
M. Minicucci ◽  
A. Di Cicco ◽  
...  

2019 ◽  
Vol 74 (4) ◽  
pp. 357-363
Author(s):  
Daniela Vitzthum ◽  
Hubert Huppertz

AbstractThe mixed cation triel borate Ga4In4B15O33(OH)3 was synthesized in a Walker-type multianvil apparatus at high-pressure/high-temperature conditions of 12.5 GPa and 1300°C. Although the product could not be reproduced in further experiments, its crystal structure could be reliably determined via single-crystal X-ray diffraction data. Ga4In4B15O33(OH)3 crystallizes in the tetragonal space group I41/a (origin choice 2) with the lattice parameters a = 11.382(2), c = 15.244(2) Å, and V = 1974.9(4) Å3. The structure of the quaternary triel borate consists of a complex network of BO4 tetrahedra, edge-sharing InO6 octahedra in dinuclear units, and very dense edge-sharing GaO6 octahedra in tetranuclear units.


1961 ◽  
Vol 5 ◽  
pp. 276-284
Author(s):  
E. L. Moore ◽  
J. S. Metcalf

AbstractHigh-temperature X-ray diffraction techniques were employed to study the condensation reactions which occur when sodium orthophosphates are heated to 380°C. Crystalline Na4P2O7 and an amorphous phase were formed first from an equimolar mixture of Na2HPO4·NaH2PO4 and Na2HPO4 at temperatures above 150°C. Further heating resulted in the formation of Na5P3O10-I (high-temperature form) at the expense of the crystalline Na4P4O7 and amorphous phase. Crystalline Na5P3O10-II (low-temperature form) appears after Na5P3O10-I.Conditions which affect the yield of crystalline Na4P2O7 and amorphous phase as intermediates and their effect on the yield of Na5P3O10 are also presented.


1988 ◽  
Vol 133 ◽  
Author(s):  
K. S. Kumar ◽  
S. K. Mannan

ABSTRACTThe mechanical alloying behavior of elemental powders in the Nb-Si, Ta-Si, and Nb-Ta-Si systems was examined via X-ray diffraction. The line compounds NbSi2 and TaSi2 form as crystalline compounds rather than amorphous products, but Nb5Si3 and Ta5Si3, although chemically analogous, respond very differently to mechanical milling. The Ta5Si3 composition goes directly from elemental powders to an amorphous product, whereas Nb5Si3 forms as a crystalline compound. The Nb5Si3 compound consists of both the tetragonal room-temperature α phase (c/a = 1.8) and the tetragonal high-temperature β phase (c/a = 0.5). Substituting increasing amounts of Ta for Nb in Nb5Si3 initially stabilizes the α-Nb5Si3 structure preferentially, and subsequently inhibits the formation of a crystalline compound.


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