Characterization of carbides in M50NiL

1991 ◽  
Vol 49 ◽  
pp. 606-607
Author(s):  
L. S. Lin ◽  
K. P. Gumz ◽  
A. V. Karg ◽  
C. C. Law
Keyword(s):  
Temperature Effects ◽  
Base Composition ◽  
Lattice Parameter ◽  
Control Surface ◽  
Carbide Formation ◽  
Particle Sizes ◽  
Low Carbon ◽  
Fee Structure ◽  
Heat Treated

Carbon and temperature effects on carbide formation in the carburized zone of M50NiL are of great importance because they can be used to control surface properties of bearings. A series of homogeneous alloys (with M50NiL as base composition) containing various levels of carbon in the range of 0.15% to 1.5% (in wt.%) and heat treated at temperatures between 650°C to 1100°C were selected for characterizations. Eleven samples were chosen for carbide characterization and chemical analysis and their identifications are listed in Table 1.Five different carbides consisting of M6C, M2C, M7C3 and M23C6 were found in all eleven samples examined as shown in Table 1. M6C carbides (with least carbon) were found to be the major carbide in low carbon alloys (<0.3% C) and their amounts decreased as the carbon content increased. In sample C (0.3% C), most particles (95%) encountered were M6C carbide with a particle sizes range between 0.05 to 0.25 um. The M6C carbide are enriched in both Mo and Fe and have a fee structure with lattice parameter a=1.105 nm (Figure 1).

scholarly journals Austenite Reverse Transformation in a Q&P Route of Mn and Ni Added Steels

Metals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 862 ◽  
Author(s):  
Maribel Arribas ◽  
Teresa Gutiérrez ◽  
Eider Del Molino ◽  
Artem Arlazarov ◽  
Irene De Diego-Calderón ◽  
...  
Keyword(s):  
Microstructure Evolution ◽  
Microstructural Characterization ◽  
Carbon Steels ◽  
Reverse Transformation ◽  
Low Carbon ◽  
Effective Mechanism ◽  
Low Carbon Steels ◽  
Heat Treated ◽  
Final Microstructure

In this work, four low carbon steels with different contents of Mn and Ni were heat treated by quenching and partitioning (Q&P) cycles where high partitioning temperatures, in the range of 550 °C–650 °C, were applied. In order to elucidate the effect of applying these high partitioning temperatures with respect to more common Q&P cycles, the materials were also heat treated considering a partitioning temperature of 400 °C. The microstructure evolution during the Q&P cycles was studied by means of dilatometry tests. The microstructural characterization of the treated materials revealed that austenite retention strongly depended on the alloy content and partitioning conditions. It was shown that the occurrence of austenite reverse transformation (ART) in the partitioning stage in some of the alloys and conditions was a very effective mechanism to increase the austenite content in the final microstructure. However, the enhancement of tensile properties achieved by the application of high partitioning temperature cycles was not significant.

XRD and Tem Characterization of Cathodic MnO2 and Discharge Products in the Li-MnO2 Cell

1995 ◽  
Vol 393 ◽  
Author(s):  
Y. Shao ◽  
S.A. Hackney ◽  
B.C. Cornilsen
Keyword(s):  
Lattice Parameter ◽  
X Ray Diffraction ◽  
Electrolytic Manganese Dioxide ◽  
Cathodic Material ◽  
X Ray ◽  
Heat Treated ◽  
Electrolytic Manganese ◽  
Xrd Patterns ◽  
Convergent Beam

ABSTRACTThe crystal structures of the undischarged, heat-treated electrolytic manganese dioxide (HEMD) and discharge products are characterized by high spatial resolution convergent beam electron diffraction (CBED). The results are compared with the x-ray diffraction (XRD) patterns characterized by broad, diffuse peaks. The CBED results for HEMD show that the starting cathodic material has the pyrolusite space group, but with a range of c/a ratios. The variability of the lattice parameter from grain to grain is found to coincide with the broadening on the low angle side of the XRD peaks. The CBED patterns of discharge products suggest a reduction range in c/a ratios and the formation of another phase.

Mechanochemical Carboaluminothermic Reduction of V2O5 to Produce VC-Al2O3 Nanocomposite

2012 ◽  
Vol 59 (2) ◽  
Author(s):  
Mohsen Hossein-Zadeh ◽  
Fatemeh Tebyani ◽  
Javad Yazdani Cherati ◽  
Omid Mirzaee
Keyword(s):  
Crystallite Size ◽  
Morphological Evolution ◽  
Xrd Analysis ◽  
Lattice Parameter ◽  
Milling Process ◽  
Xrd Study ◽  
Heat Treated ◽  
Nanocomposite Powders

The aim of this investigation is to produce VC–Al2O3 nanocomposite by reducing V2O5 with Aluminum and black carbon powders via mechanochemical process. The effect of milling time on this process was investigated. Milling process was done powder mixture at a rotation speed of 250 rpm for different times. Results showed that VCx has been synthesized after 1 hour of milling. The characterization of phase formation, crystallite size, strain percentage and lattice parameter was done by XRD analysis. To study the morphological evolution and determination of particle size of nanocomposite powders, Field Emission Scanning Electron Microscope (FESEM) was used. The crystallite size and lattice strain were determined by Williamson-Hall method. XRD study showed that for 6 h milling, the width of V4C3 peaks increased while the crystallite size of these phases decreased to about 27nm. In order to formVC–Al2O3 nanocomposite, the mixture was heat treated with the aid of microwave oven. The composite revealed good microwave absorption and heated up to 1150°C.

scholarly journals Effect of the Carburizing Layer on the Morphology of Chromium Carbides

2020 ◽  
pp. 187-193
Author(s):  
Rabah Boubaaya ◽  
Omar Allaoui ◽  
Younes Benarioua ◽  
Zied Driss
Keyword(s):  
Phase Shift ◽  
Solid Phase ◽  
Low Carbon Steel ◽  
Lattice Parameter ◽  
Thin Layers ◽  
Low Carbon ◽  
Metastable Transition ◽  
Steel Substrates ◽  
Germination And Growth

Low carbon steel substrates were face-hardened by cementing, after which thin layers of chromium were deposited electrolytically on these substrates. After deposition, the samples were exposed to isothermal annealing at a temperature of 950°C. The characterization of the thin layers was carried out by means of optical microscopy and interferometry using the Vickers microhardness test. The obtained results allowed establishing the phase shift kinetics (under the effect of the cementing layer) in thin layers of chromium, which are transformed into chromium carbide when passing through metastable transition phases. These transformations were due to diffusion of the carbon atoms coming from the layer of cementing, germination and growth in solid phase. This fact has been examined taking into account the annealing temperature, the lattice parameter evolution and the deposited chromium layer morphology. As to mechanical properties, it was established that the micro-hardness depends on the phase shift evolution

Modulated structures in (Bi,Pb)-Sr-Ca-Cu-O films

1990 ◽  
Vol 48 (4) ◽  
pp. 62-63
Author(s):  
Shozo Ikeda ◽  
Hirotoshi Hayakawa ◽  
Daniel R. Dietderich
Keyword(s):  
Rf Magnetron Sputtering ◽  
Potential Method ◽  
High Tc ◽  
Bscco System ◽  
Heat Treated ◽  
Modulated Structures ◽  
High Tc Phase ◽  
Deposited Films ◽  
Sputtering System

Pb addition makes easier to form the high Tc phase in the BSCCO system. However, Pb easily vaporized at high temperature. A controlled Pb potential method has been applied to grow the high Tc phase in films. Initially, films are deposited on cleaved MgO substrates using an rf magnetron sputtering system. These amorphous as-deposited films are heat treated in a sealed gold capsule along with a large pellet of Pb-added BSCCO. Details of the process and characterization of the films have been reported elsewhere (1). Films trated for 0.5h at 850° C contain mainly the low Tc phase with a small amount of the high Tc phase. Hawever, films treated for 3h at 850°C consist mainly of the high Tc phase. This film is superconductive with a Tc(zero) of 106K. The Pb/Bi ratio of the films, analysed by SEM- EDS, are 0.12 and 0.18 for heat tratment times of 0.5 and 3h, respectively. The present study investigates the modulated structures of these films using HREM.

CBED analysis of impurity distributions in AlN

1990 ◽  
Vol 48 (4) ◽  
pp. 214-215
Author(s):  
Daniel Callahan ◽  
G. Thomas
Keyword(s):  
Aluminum Nitride ◽  
Bulk Material ◽  
Strong Dependence ◽  
Lattice Parameter ◽  
Promising Technique ◽  
Nitride Ceramics ◽  
Surface Phases ◽  
Convergent Beam ◽  
Oxygen Impurities

Oxygen impurities may significantly influence the properties of nitride ceramics with a strong dependence on the microstructural distribution of the impurity. For example, amorphous oxygen-rich grain boundary phases are well-known to cause high-temperature mechanical strength degradation in silicon nitride whereas solutionized oxygen is known to decrease the thermal conductivity of aluminum nitride. Microanalytical characterization of these impurities by spectral methods in the AEM is complicated by reactions which form oxygen-rich surface phases not representative of the bulk material. Furthermore, the impurity concentrations found in higher quality ceramics may be too low to measure by EDS or PEELS. Consequently an alternate method for the characterization of impurities in these ceramics has been investigated.Convergent beam electron diffraction (CBED) is a promising technique for the study of impurity distributions in aluminum nitride ceramics. Oxygen is known to enter into stoichiometric solutions with AIN with a consequent decrease in lattice parameter.

INCO ALLOY MS 250

Alloy Digest ◽  
1987 ◽  
Vol 36 (11) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Intermetallic Compound ◽  
Yield Strength ◽  
Physical Properties ◽  
Tensile Properties ◽  
Heat Treating ◽  
Low Carbon ◽  
Martensitic Matrix ◽  
Inco Alloy ◽  
Heat Treated

Abstract INCO Alloy MS 250 is a cobalt-free managing steel with nominal yield strength of 250,000 psi, fully heat-treated. Strengthening results from intermetallic-compound precipitation in a low-carbon martensitic matrix. It has excellent weldability. This datasheet provides information on composition, physical properties, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: SA-426. Producer or source: Inco Alloys International Inc..

CANNON-MUSKEGON 8620

Alloy Digest ◽  
1973 ◽  
Vol 22 (12) ◽  
Keyword(s):  
Wear Resistance ◽  
Corrosion Resistance ◽  
Alloy Steel ◽  
Investment Casting ◽  
Silicon Content ◽  
Heat Treating ◽  
Low Carbon ◽  
Heat Treated ◽  
Casting Industry ◽  
Small Parts

Abstract CANNON-MUSKEGON 8620 is a low-carbon triple-alloy steel capable of being carburized for wear resistance or heat treated for toughness. This steel is suitable for many engineering applications, and is used in large quantities in the investment casting industry for small parts. A higher silicon content is permissible in this steel than in AISI 8620 (wrought) alloy steel. This datasheet provides information on composition, physical properties, elasticity, and tensile properties. It also includes information on corrosion resistance as well as casting, heat treating, machining, joining, and surface treatment. Filing Code: SA-299. Producer or source: Cannon-Muskegon Corporation.

3-D Characterization of Global and Local Microstructural Effects on Spall Damage in Shock Loaded FCC Metals: Experimental and Modeling

2013 ◽  
Author(s):  
A. Brown ◽  
K. Krishnan ◽  
L. Wayne ◽  
P. Peralta ◽  
S. N. Luo ◽  
...  
Keyword(s):  
Weak Link ◽  
Heat Treatments ◽  
Taylor Factor ◽  
Weak Links ◽  
Spall Damage ◽  
Heat Treated ◽  
Microstructural Effects ◽  
Global And Local ◽  
Low Pressures

Global and local microstructural weak links for spall damage were investigated using 3-D characterization in polycrystalline (PC) and multicrystalline (MC) copper samples, respectively. All samples were shocked via flyer-target plate experiments using a laser drive at low pressures (2–6 GPa). The flyer plates measured approximately 500 μm thick and 8 mm in diameter and the target plates measured approximately 1000 μm thick and 10 mm in diameter. Electron Backscattering Diffraction (EBSD) and optical microscopy were used to determine to presence of voids and relate them to the surrounding microstructure. Statistics on the strength of grain boundaries (GBs) was conducted by analyzing PC samples and collecting the misorientation across GBs with damage present, and it was found that a misorientation range of 25–50° is favorable for damage. Statistics were also taken of copper PC samples that had undergone different heat treatments and it was found that although the 25–50° range is less dominant, it is still favorable for damage nucleation. Removal of initial plastic strain via heat treatments and an increase in Σ3 CSL boundaries, indicative of strong annealing twins, also led to an increased amount of transgranular damage. 3-D X-ray tomography data were used to investigate the shape of the voids present in untreated, as received and heat treated samples. It was found that the as received sample contained a higher amount of “disk”, or, “sheet-like” voids indicative of intergranular damage, whereas the heat treated samples had a higher fraction of spherical shaped voids, indicative of transgranular damage. MC samples were used to study microstructural weak links for spall damage because the overall grain size is much larger than the average void size, making it possible to determine which GBs nucleated damage. Simulations and experimental analysis of damage sites with large volumes indicate that high Taylor factor mismatches with respect to the crystallographic grain GB normal is the primary cause for the nucleation of damage at a GB interface and a low Taylor factor along the shock direction in either grain drives void growth perpendicular to the GB. Cases where experimental results show damage and simulation results show no damage are attributed to the presence of an intrinsic microstructural weak link, such as an incoherent twin boundary.

scholarly journals Compositional, structural, and surface characterization of heat-treated halloysite samples: Influence of surface treatment on photochemical activity

2021 ◽  
Vol 212 ◽  
pp. 106222
Author(s):  
Balázs Zsirka ◽  
Veronika Vágvölgyi ◽  
Katalin Győrfi ◽  
Erzsébet Horváth ◽  
Róbert K. Szilágyi ◽  
...  
Keyword(s):  
Surface Treatment ◽  
Surface Characterization ◽  
Photochemical Activity ◽  
Heat Treated
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