Co-optimization of matrix phase and second phase for improved room-temperature TCR of (La0.6Na0.4MnO3)1-Ag composites

2021 ◽  
pp. 130714
Author(s):  
Shuaizhao Jin ◽  
Xiaohan Yu ◽  
Xiaoli Guan ◽  
Xin Gu ◽  
Yixin Yan ◽  
...  
Keyword(s):  
Room Temperature ◽  
Matrix Phase ◽  
Second Phase

The Reactivity of CaTi4(PO4)6 with Alumina and Y-TZP Ceramics

2007 ◽  
Vol 361-363 ◽  
pp. 787-790
Author(s):  
Sabina Beranič Klopčič ◽  
Irena Pribošič ◽  
Tomaž Kosmač ◽  
Ute Ploska ◽  
Georg Berger
Keyword(s):  
Room Temperature ◽  
Xrd Analysis ◽  
Second Phase ◽  
Reaction Products ◽  
Stabilized Zirconia ◽  
Monoclinic Zro2 ◽  
Commercial Alumina ◽  
The Matrix ◽  
Different Temperatures ◽  
Edx Analyses

The reactivity of CaTi4(PO4)6 (CTP) with alumina and yttria-stabilized zirconia (Y-TZP) ceramics was studied. CTP powder was synthesized and composites with commercial alumina or zirconia matrices containing 10 wt% of CTP were prepared. They were sintered at different temperatures and characterized using XRD, SEM, and EDX analyses. The results showed that the alumina/CTP and Y-TZP/CTP composites start to react below 1000 °C. In the alumina/CTP composite the first reaction product, detected at 970 °C, was AlPO4. At temperatures above 1280 °C TiO2 and CaTiO3 were also formed and no CTP peaks could be detected using XRD analysis. The composite sintered at 1500 °C consisted of Al2O3 matrix, AlPO4, TiO2, CaTiO3 and Al2TiO5. The reaction products formed in the Y-TZP/CTP composite at 970 °C were TiO2 and Ca2Zr7O16. At higher sintering temperatures, 1280 °C and above, CTP was no longer present, Ca2Zr7O16 decomposed, forming CaO2 and ZrO2, and Y2O3 was consumed to form YPO4. Consequently, upon cooling to room temperature the matrix phase transformed to monoclinic ZrO2. Based on these results it can be concluded that CTP is not a suitable bioactive second phase for the fabrication of CTP composites with alumina or zirconia matrices.

scholarly journals Microstructure and Tensile Properties of Graphene-Oxide-Reinforced High-Temperature Titanium-Alloy-Matrix Composites

Materials ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3358 ◽  
Author(s):  
Hang Chen ◽  
Guangbao Mi ◽  
Peijie Li ◽  
Xu Huang ◽  
Chunxiao Cao
Keyword(s):  
Tensile Strength ◽  
Titanium Alloy ◽  
Graphene Oxide ◽  
High Temperature ◽  
Yield Strength ◽  
Room Temperature ◽  
Second Phase ◽  
Matrix Composites ◽  
Alloy Matrix ◽  
The Matrix

In this study, graphene-oxide (GO)-reinforced Ti–Al–Sn–Zr–Mo–Nb–Si high-temperature titanium-alloy-matrix composites were fabricated by powder metallurgy. The mixed powders with well-dispersed GO sheets were obtained by temperature-controlled solution mixing, in which GO sheets adsorb on the surface of titanium alloy particles. Vacuum deoxygenating was applied to remove the oxygen-containing groups in GO, in order to reduce the introduction of oxygen. The compact composites with refined equiaxed and lamellar α phase structures were prepared by hot isostatic pressing (HIP). The results show that in-situ TiC layers form on the surface of GO and GO promotes the precipitation of hexagonal (TiZr)6Si3 particles. The composites exhibit significant improvement in strength and microhardness. The room-temperature tensile strength, yield strength and microhardness of the composite added with 0.3 wt% GO are 9%, 15% and 27% higher than the matrix titanium alloy without GO, respectively, and the tensile strength and yield strength at 600 °C are 3% and 21% higher than the matrix alloy. The quantitative analysis indicates that the main strengthening mechanisms are load transfer strengthening, grain refinement and (TiZr)6Si3 second phase strengthening, which accounted for 48%, 30% and 16% of the improvement of room-temperature yield strength, respectively.

The Hall Carrier Mobility of AgBiTe2-Ag2Te Composite

2001 ◽  
Vol 691 ◽  
Author(s):  
T. Sakakibara ◽  
Y. Takigawa ◽  
K. Kurosawa
Keyword(s):  
Electrical Conductivity ◽  
Composite Material ◽  
Composite Materials ◽  
Hall Coefficient ◽  
Carrier Mobility ◽  
Matrix Phase ◽  
Second Phase ◽  
Temperature Range ◽  
The Matrix ◽  
Van Der Pauw

ABSTRACTWe prepared a series of (AgBiTe2)1−x(Ag2Te)x(0≤×≤1) composite materials by melt and cool down [1]. The Hall coefficient and the electrical conductivity were measured by the standard van der Pauw technique over the temperature range from 93K to 283K from which the Hall carrier mobility was calculated. Ag2Te had the highest mobility while the mobility of AgBiTe2was the lowest of all samples at 283K. However the mobility of the (AgBiTe2)0.125(Ag2Te)0.875composite material was higher than the motility of Ag2Te below 243K. It seems that a small second phase dispersed in the matrix phase is effective against the increased mobility.

scholarly journals Identification of an Al–Ni–O precipitate in combustion-synthesized NiAl

2000 ◽  
Vol 33 (5) ◽  
pp. 1217-1222
Author(s):  
A. Biswas ◽  
Madangopal K. ◽  
J. B. Singh ◽  
S. K. Roy ◽  
S. Banerjee
Keyword(s):  
Room Temperature ◽  
Point Group ◽  
Composition Analysis ◽  
Second Phase ◽  
X Ray ◽  
Selected Area Electron Diffraction ◽  
Phase Precipitate ◽  
Transmission Electron ◽  
Chemical Composition Analysis

The complete identity of a second-phase precipitate detected by transmission electron microscopy in combustion-synthesized NiAl was established. The crystal structure, including the point group, the space group and the lattice parameters, was determined by convergent and selected-area electron diffraction techniques. Energy dispersive X-ray spectroscopy was used for the determination of the chemical composition. Analysis established the phase to be the solid solution of NiO in Al2O3and presented evidence of the hitherto unreported room-temperature solubility.

FACTORS INFLUENCING THE AMOUNT OF INSULIN EXTRACTABLE FROM BEEF PANCREAS: I. EFFECTS OF AGING FRESH PANCREAS AT ROOM TEMPERATURE

1957 ◽  
Vol 35 (7) ◽  
pp. 527-535 ◽  
Author(s):  
Gerald A. Wrenshall ◽  
Charles H. Best ◽  
W. Stanley Hartroft
Keyword(s):  
Experimental Evidence ◽  
Beta Cells ◽  
Room Temperature ◽  
Second Phase ◽  
Structural Components ◽  
Factors Influencing ◽  
Two Phases ◽  
Early Rise ◽  
Effects Of Aging ◽  
New Formation

Effects on the concentration of extractable insulin of aging fresh beef pancreas at temperatures in the 22–26 °C. range have been described. Two phases of change with time of aging have been observed, describable as a transient increase superimposed on a progressive fall toward zero in the concentration of insulin extractable from the pancreas. In two of the eight experiments reported only the second phase was detected.Various hypotheses concerning the cause of the first phase are considered. The available experimental evidence is considered to support the hypothesis that the early rise in extractable insulin resulted from the continuing new formation of insulin from structural components already present in the cytoplasm of the beta cells at time of exsanguination, or diffusing into it thereafter. The progressive fall in the extractable insulin during the second phase must have resulted from destruction or inactivation of insulin within the pancreas.The bearing of these recent findings on the usage of the term "The insulin content of the pancreas" has been discussed.

Research on the Second Phase of Spray Forming Al-8.5Fe-1.3V-1.7Si Aluminum Alloy

2014 ◽  
Vol 886 ◽  
pp. 36-40
Author(s):  
Rong Hua Zhang ◽  
Bao Hong Zhu ◽  
Xiao Ping Zheng
Keyword(s):  
Electron Microscopy ◽  
Phase Transition ◽  
Transmission Electron Microscopy ◽  
Aluminum Alloy ◽  
Room Temperature ◽  
Spray Forming ◽  
Heating Process ◽  
Second Phase ◽  
Transmission Electron ◽  
Second Phases

Heat-resistant Al-8.5Fe-1.3V-1.7Si aluminum alloys were prepared by spray forming technique. The phase transition of deposited alloys from room temperature to 500°C was measured by Differential Scanning Calorimeter. The organization and the second phases of the alloys were observed and studied by transmission electron microscopy. The research results show that No endothermic peak appears in the deposited alloys during heating process, there is no phase transition occur in the alloy during the heating process from room temperature to 500°C. The deposited alloys mainly include α-Al and α-Al12(Fe,V)3Si phase. Under the transmission electron microscopy, there are also a small amount of slug, fan-shaped, needle-like, block, strip second phases, these phases are Al12Fe3Si, Al8Fe2Si, θ-Al13Fe4, Al9FeSi3, Al6Fe.

Cavity of Al-Cu-Mg Alloy during Superplastic Deformation

2007 ◽  
Vol 551-552 ◽  
pp. 645-650
Author(s):  
Min Wang ◽  
Hong Zhen Guo ◽  
Y.J. Liu
Keyword(s):  
Strain Rate ◽  
Grain Boundaries ◽  
Superplastic Deformation ◽  
Room Temperature ◽  
Mg Alloy ◽  
Deformation Condition ◽  
Second Phase ◽  
Rate Condition ◽  
Second Phase Particles ◽  
Strain Rate Condition

According to the characteristic of appearing cavitation in the metals during superplastic deformation, the influence of strain rate on cavity evolvement, the influence of cavity on superplastic deformation capability, and the formation, development process of cavity were investigated for Al-Cu-Mg alloy (i.e. coarse–grained LY12). The results show that: ①The pore nucleation occurs not only at triangle grain boundaries, but also along nearby the second phase particles, and even within grains. The cavities at the triangle grain boundaries are present in V-shape, others near the second phase particles and within grains are present in O-shape. These cavities may result from disharmony slippage of grain boundaries. ②The tendency of cavity development decreases with increasing of strain-rate. In lower strain-rate condition, though Al-Cu-Mg alloy has better superplasticity, many big cavities in the specimen may reduce the room temperature properties of the alloy. In higher strain-rate condition, Al-Cu-Mg alloy has certain superplasticity and room temperature properties as well as few cavities forming. By analyzing, viscous layer on grain boundaries is very thin and grain sizes can be refined during their extruding and rotating each other in higher strain-rate superplastic deformation condition. ③Growth and coalescence of cavity are the main reason of the superplastic fracture of Al-Cu-Mg alloy. And small and a certain amount of cavities with dispersion and independence state are very useful to crystal boundary slippage.

Ultra-Fine Grained Al-SiC Metal Matrix Composite by Rotary Swaging Process

2011 ◽  
Vol 702-703 ◽  
pp. 320-323 ◽  
Author(s):  
Sivaswamy Giribaskar ◽  
Gouthama ◽  
Rajesh Prasad
Keyword(s):  
Metal Matrix Composite ◽  
Matrix Composite ◽  
Metal Matrix ◽  
Room Temperature ◽  
Volume Fraction ◽  
Second Phase ◽  
Fine Grained ◽  
Rotary Swaging ◽  
Sic Particles ◽  
Dynamic Recrystallisation

In present study microstructural evolution during swaging on aluminium alloy based metal matrix composite (MMC) reinforced with 15% volume fraction silicon carbide (SiC) particles is presented. Samples were swaged at room temperature in steps with reducing die dimensions using rotary swaging technique. SEM and TEM are used to study the microstructural characteristics of swaged samples. SEM observations were made to understand the flow and deformation characteristics of deforming aluminium matrix in the presence of second phase and reinforced SiC particles during swaging. TEM observations on swaged samples confirmed the formation of ultra-fine grains in Al-15%SiC MMC. It is shown that the dynamic recrystallisation occurring in the proximities of second phase particles during the deformation at room temperature, leads to very fine grained microstructure.

The Room Temperature and Elevated Temperature Fracture Toughness Response of Alloy A-286

1978 ◽  
Vol 100 (2) ◽  
pp. 195-199 ◽  
Author(s):  
W. J. Mills
Keyword(s):  
Fracture Toughness ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Second Phase ◽  
Surface Micromorphology ◽  
Second Phase Particles ◽  
The Matrix ◽  
Temperature Fracture ◽  
Increasing Temperature ◽  
Base Superalloy

The elastic-plastic fracture toughness (JIc) response of precipitation strengthened Alloy A-286 has been evaluated by the multi-specimen R-curve technique at room temperature, 700 K (800°F) and 811 K (1000°F). The fracture toughness of this iron-base superalloy was found to decrease with increasing temperature. This phenomenon was attributed to a reduction in the materials’s strength and ductility at elevated temperatures. Electron fractographic examination revealed that the overall fracture surface micromorphology, a duplex dimple structure coupled with stringer troughs, was independent of test temperature. In addition, the fracture resistance of Alloy A-286 was found to be weakened by the presence of a nonuniform distribution of second phase particles throughout the matrix.

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