An Irreversible Phase Transformation in sodium Acetyl-Acetonate Compound

1975 ◽  
Vol 31 (1-2) ◽  
pp. 9-19 ◽  
Author(s):  
R. Kamel ◽  
M. Hilal ◽  
A. H. Eid ◽  
A. Sawaby
Keyword(s):  
Phase Transformation ◽  
Irreversible Phase Transformation ◽  
Acetyl Acetonate

Humidity sensitive irreversible phase transformation of an open-framework Zinc phosphate and its water-assisted high proton conduction properties

2021 ◽  
Author(s):  
Jing-Wei Yu ◽  
Hai-Jiao Yu ◽  
Qiu Ren ◽  
Jin Zhang ◽  
Yang Zou ◽  
...  
Keyword(s):  
Phase Transformation ◽  
High Temperature ◽  
Zinc Phosphate ◽  
High Temperature Phase ◽  
Temperature Phase ◽  
Open Framework ◽  
High Proton ◽  
Irreversible Phase Transformation ◽  
Low Temperature Phase ◽  
Conduction Properties

Open-framework zinc phosphate (NMe4)(ZnP2O8H3) undergoes irreversible phase transformation. Structural transformation with α (NMe4.Zn[HPO4][H2PO4] the low-temperature phase) and β (NMe4.ZnH3[PO4]2 the high-temperature phase) (Tc=149 °C) and conduction properties were investigated by...

Microstructure and Phase Transformation Behavior of Ni-Mn-Fe High-Temperature Shape Memory Alloys

2015 ◽  
Vol 833 ◽  
pp. 63-66
Author(s):  
Cui Ping Wang ◽  
Yu Ding Liu ◽  
Shui Yuan Yang ◽  
Xing Jun Liu
Keyword(s):  
Phase Transformation ◽  
High Temperature ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Transformation Behavior ◽  
Phase Transformation Behavior ◽  
Heating And Cooling ◽  
High Transformation ◽  
Irreversible Phase Transformation ◽  
Very High

The microstructure and phase transformation behavior of Ni-Mn-Fe high-temperature shape memory alloys including Ni40+xFe10Mn50-x (x = 0, 10) were investigated. The results show that both two alloys exhibit single fcc γ phase annealed at 900°C for 1 day. When these quenched alloys are again annealed at 500°C for 20 days, they almost exhibit main tetragonal θ martensite. The microstructural evolutions are consistent with the results of phase transformation measurements. It is clearly found that there is an irreversible phase transformation around 480°C ~ 570°C, which is associated with the formation of tetragonal θ martensite from γ phase. Afterwards, the reversible martensitic transformation occurs during heating and cooling with very high transformation temperature.

scholarly journals Irreversible phase transformation in a CoCrFeMnNi high entropy alloy under hydrostatic compression

2018 ◽  
Vol 14 ◽  
pp. 10-14 ◽  
Author(s):  
E-Wen Huang ◽  
Chih-Ming Lin ◽  
Jayant Jain ◽  
Sean R. Shieh ◽  
Ching-Pao Wang ◽  
...  
Keyword(s):  
Phase Transformation ◽  
Hydrostatic Compression ◽  
High Entropy Alloy ◽  
High Entropy ◽  
Irreversible Phase Transformation

First-principles study on properties of Sn-doped LiCoO2 for Li-ion batteries

2021 ◽  
Author(s):  
Ruihan Yang ◽  
Mengke Guan ◽  
Ruirui Zhao ◽  
Qiong Luo
Keyword(s):  
Phase Transformation ◽  
Lithium Ion Battery ◽  
High Voltage ◽  
First Principles ◽  
Lithium Ion ◽  
Li Ion Batteries ◽  
Rocksalt Structure ◽  
Battery Electrode ◽  
Li Ion ◽  
Irreversible Phase Transformation

The key for the application of LiCoO2 as lithium-ion battery electrode under high voltage is to suppress the irreversible phase transformation from the layered to the spinel/rocksalt structure during cycling....

Phase Transformation In Ti-6al-4v Alloys

1972 ◽  
Vol 30 ◽  
pp. 584-585
Author(s):  
Shiro Fujishiro
Keyword(s):  
Phase Transformation ◽  
Grain Boundary ◽  
Cryogenic Temperature ◽  
Β Phase ◽  
Heat Treated ◽  
Mixed Microstructure ◽  
Ductile Behavior

The Ti-6 wt.% Al-4 wt.% V commercial alloys have exhibited an improved formability at cryogenic temperature when the alloys were heat-treated prior to the tests. The author was interested in further investigating this unusual ductile behavior which may be associated with the strain-induced transformation or twinning of the a phase, enhanced at lower temperatures. The starting materials, supplied by RMI Co., Niles, Ohio were rolled mill products in the form of 40 mil sheets. The microstructure of the as-received materials contained mainly ellipsoidal α grains measuring between 1 and 5μ. The β phase formed an undefined grain boundary around the a grains. The specimens were homogenized at 1050°C for one hour, followed by aging at 500°C for two hours, and then quenched in water to produce the α/β mixed microstructure.

Microstructural and Microchemical Characterization of Nickel Sulfide Inclusions in Plate Glass

1991 ◽  
Vol 49 ◽  
pp. 962-963
Author(s):  
J. Cooper ◽  
O. Popoola ◽  
W. M. Kriven
Keyword(s):  
Thermal Expansion ◽  
Phase Transformation ◽  
Glass Matrix ◽  
Nickel Sulfide ◽  
Plate Glass ◽  
Thermal Expansion Mismatch ◽  
Volume Increase ◽  
Β Phase ◽  
Microchemical Characterization

Nickel sulfide inclusions have been implicated in the spontaneous fracture of large windows of tempered plate glass. Two alternative explanations for the fracture-initiating behaviour of these inclusions have been proposed: (1) the volume increase which accompanies the α to β phase transformation in stoichiometric NiS, and (2) the thermal expansion mismatch between the nickel sulfide phases and the glass matrix. The microstructure and microchemistry of the small inclusions (80 to 250 μm spheres), needed to determine the cause of fracture, have not been well characterized hitherto. The aim of this communication is to report a detailed TEM and EDS study of the inclusions.

AEM of reaction-bonded SiC

1992 ◽  
Vol 50 (1) ◽  
pp. 344-345
Author(s):  
K Das Chowdhury ◽  
R. W. Carpenter ◽  
W. Braue
Keyword(s):  
Mechanical Properties ◽  
Phase Transformation ◽  
High Temperature ◽  
Epitaxial Growth ◽  
Liquid Silicon ◽  
Structural Ceramic ◽  
Few Data

Research on reaction-bonded SiC (RBSiC) is aimed at developing a reliable structural ceramic with improved mechanical properties. The starting materials for RBSiC were Si,C and α-SiC powder. The formation of the complex microstructure of RBSiC involves (i) solution of carbon in liquid silicon, (ii) nucleation and epitaxial growth of secondary β-SiC on the original α-SiC grains followed by (iii) β>α-SiC phase transformation of newly formed SiC. Due to their coherent nature, epitaxial SiC/SiC interfaces are considered to be segregation-free and “strong” with respect to their effect on the mechanical properties of RBSiC. But the “weak” Si/SiC interface limits its use in high temperature situations. However, few data exist on the structure and chemistry of these interfaces. Microanalytical results obtained by parallel EELS and HREM imaging are reported here.

Phase transformation and layer evolution in molybdenum disilicide-silicon carbide nanolayered coatings

1994 ◽  
Vol 52 ◽  
pp. 538-539
Author(s):  
H. Kung ◽  
T. R. Jervis ◽  
J.-P. Hirvonen ◽  
M. Nastasi ◽  
T. E. Mitchell ◽  
...  
Keyword(s):  
Phase Transformation ◽  
High Temperature ◽  
Oxidation Resistance ◽  
Elevated Temperatures ◽  
Matrix Material ◽  
Molybdenum Disilicide ◽  
High Temperature Strength ◽  
Cross Sectional ◽  
Good Oxidation Resistance ◽  
Structural Applications

MoSi2 is a potential matrix material for high temperature structural composites due to its high melting temperature and good oxidation resistance at elevated temperatures. The two major drawbacksfor structural applications are inadequate high temperature strength and poor low temperature ductility. The search for appropriate composite additions has been the focus of extensive investigations in recent years. The addition of SiC in a nanolayered configuration was shown to exhibit superior oxidation resistance and significant hardness increase through annealing at 500°C. One potential application of MoSi2- SiC multilayers is for high temperature coatings, where structural stability ofthe layering is of major concern. In this study, we have systematically investigated both the evolution of phases and the stability of layers by varying the heat treating conditions.Alternating layers of MoSi2 and SiC were synthesized by DC-magnetron and rf-diode sputtering respectively. Cross-sectional transmission electron microscopy (XTEM) was used to examine three distinct reactions in the specimens when exposed to different annealing conditions: crystallization and phase transformation of MoSi2, crystallization of SiC, and spheroidization of the layer structures.

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