Characteristics of FeCuAl Powder Compacts Formed through Uniaxial Die Compaction Route

2017 ◽  
Vol 264 ◽  
pp. 103-106 ◽  
Author(s):  
M.M. Rahman ◽  
M.A. Ismail ◽  
H. Y. Rahman
Keyword(s):  
Electrical Resistivity ◽  
Relative Density ◽  
Bending Strength ◽  
Axial Loading ◽  
Homogeneous Distribution ◽  
Volumetric Expansion ◽  
Different Temperatures ◽  
Die Compaction ◽  
Powder Compacts ◽  
Interconnected Pores

This paper presents the development of FeCuAl powder compacts through uniaxial die compaction process. Iron powder ASC 100.29 was mechanically mixed with other elemental powders, i.e., copper (Cu), and aluminum (Al) for 30 minutes at a rotation of 30 rpm. The feedstock was subsequently shaped at three different temperatures, i.e., 30°C, 150°C, and 200°C through simultaneous upward and downward axial loading of 325 MPa. The as-pressed samples termed as green compacts were then sintered in argon gas fired furnace at 800°C for three different holding times, i.e., 30, 60, and 90 min at a rate of 10°C/min. The sintered samples were characterized for their relative density, electrical resistivity, and bending strength. The microstructure of the sintered samples was also evaluated through scanning electron microscopy (SEM). The results revealed that the sample formed at 150°C and sintered for 30 min obtained the best final characteristics, i.e., higher relative density, lower volumetric expansion and electrical resistivity, and higher bending strength. Microstructure evaluation also revealed that the sample formed at 150°C and sintered for 30 min obtained more homogeneous distribution of grains and less interconnected pores compared to the other samples.

Fabrication and Performance of Al-NaI Radioactive Transmutation Targets

2010 ◽  
Vol 150-151 ◽  
pp. 580-587
Author(s):  
Hui Qiang Liu ◽  
Yi Feng ◽  
Xue Bin Zhang ◽  
Bin Li ◽  
Yan Fang Zhu ◽  
...  
Keyword(s):  
Electrical Resistivity ◽  
Powder Metallurgy ◽  
Energy Spectrum ◽  
Relative Density ◽  
Spectrum Analysis ◽  
Bending Strength ◽  
Aluminum Matrix ◽  
Energy Spectrum Analysis ◽  
And Performance

Al-NaI radioactive transmutation target was prepared by powder metallurgy. The existing way of the phase of target was analyzed by the application of XRD and its microstructure and morphology was observed by SEM. Then EDS was used for micro-area energy spectrum analysis and the property of target with different NaI was measured and compared. The results show that NaI is uniformly distributed within the aluminum matrix. The relative density and bending strength of transmutation targets decrease with the increasing content of NaI. The hardness and electrical resistivity of transmutation targets increase with the increasing content of NaI.

scholarly journals An Experimental Investigation on the Effect of Sintering Temperature and Holding Time to the Characteristics of Fecual Powder Compacts Formed at Elevated Temperature

2018 ◽  
Vol 7 (4.35) ◽  
pp. 705
Author(s):  
M. M. Rahman ◽  
M. A. Ismail ◽  
H. Y. Rahman
Keyword(s):  
Experimental Investigation ◽  
Elevated Temperature ◽  
Axial Loading ◽  
Zinc Stearate ◽  
Mixed Powder ◽  
Weight Percentage ◽  
Gas Atmosphere ◽  
Powder Mass ◽  
Die Compaction ◽  
Powder Compacts

This paper presents the experimental investigation on the effect of sintering schedule to the final properties of FeCuAl powder compacts formed at elevated temperature through a lab-scale uniaxial die compaction rig.  Iron (Fe) powder ASC100.29 was used as a main powder constituent and mixed with elemental powders which are copper (Cu) and aluminum (Al).  The weight percentage of powder mass was divided into four, i.e., iron (91.7 wt%), copper (7.5 wt%), aluminum (0.5 wt%), and zinc stearate (0.3 wt%) as lubricant.  All the powders were mixed through mechanical blending at a rotation speed of 30 rpm for 30 min.  The mixed powder mass was compacted at 150˚C by 425 MPa of axial loading from upward and downward simultaneously.  Subsequently, the defect-free green compacts were sintered under controlled argon gas atmosphere at three different sintering temperatures, i.e., 800˚C, 900˚C and 1000˚C for 120 min, 150 min and 180 min, respectively at constant sintering rate of 10˚C/min.  Afterwards, the sintered samples were characterized for their physical properties, electrical properties, mechanical properties and their microstructures were evaluated.  The results revealed that higher flexure stress was acquired by sample sintered at 1000˚C for 120 min and their microstructures were found to be better, i.e., the particles were bonded perfectly.

Preparation and Characterization of NTC NiMn2O4-La1-xCaxMnO3 (0≤x≤0.3) Composite Ceramics

2013 ◽  
Vol 716 ◽  
pp. 78-83 ◽  
Author(s):  
Hui Min Zhang ◽  
Fang Guan ◽  
Ai Min Chang ◽  
Li Jun Zhao
Keyword(s):  
Electrical Resistivity ◽  
Perovskite Structure ◽  
Spinel Structure ◽  
Thermal Constant ◽  
Inrush Current ◽  
Composite Ceramics ◽  
Sem Images ◽  
Conventional Solid State Reaction ◽  
Different Temperatures ◽  
Xrd Patterns

Composite ceramics made of spinel structure NiMn2O4 and CaO-doped perovskite structure LaMnO3 were prepared by a conventional solid state reaction and sintered at different temperatures. The XRD patterns have shown that the major phases presented in the sintered samples are NiMn2O4 compounds with the spinel structure, La1-xCaxMnO3 with the perovskite structure and NiO with a monoclinic structure. SEM images show that the density and grain size of the composite ceramics increases with sintered temperature increasing. The electrical resistivity of the composite ceramics at 25°C is found to change significantly depending on the CaO content, while the thermal constant B is still reasonably large in the range of 2400 to 3000 K. For the composition x = 0.1, the composite with a low electrical resistivity (ρ25°C=4.46Ω·cm) and moderate B value (B25/50=2762K) was obtained. These composites could be applied as potential candidates for NTC thermistors in the suppression of the inrush current.

scholarly journals Fracture Behavior of Long Fiber Reinforced Geopolymer Composites at Different Operating Temperatures

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 482
Author(s):  
Kinga Korniejenko ◽  
Beata Figiela ◽  
Celina Ziejewska ◽  
Joanna Marczyk ◽  
Patrycja Bazan ◽  
...  
Keyword(s):  
Fracture Behavior ◽  
Bending Strength ◽  
Aramid Fiber ◽  
Fine Aggregate ◽  
River Sand ◽  
Main Research ◽  
Glass Carbon ◽  
Different Temperatures ◽  
Almost All ◽  
Geopolymer Composites

The aim of this article was to analyze the fracture behavior of geopolymer composites based on fly ash or metakaolin with fine aggregate and river sand, with three types of reinforcement: glass, carbon, and aramid fiber, at three different temperatures, approximately: 3 °C, 20 °C, and 50 °C. The temperatures were selected as a future work temperature for composites designed for additive manufacturing technology. The main research method used was bending strength tests in accordance with European standard EN 12390-5. The results showed that the addition of fibers significantly improved the bending strength of all composites. The best results at room temperature were achieved for the metakaolin-based composites and sand reinforced with 2% wt. aramid fiber—17 MPa. The results at 50 °C showed a significant decrease in the bending strength for almost all compositions, which are unexpected results, taking into account the fact that geopolymers are described as materials dedicated to working at high temperatures. The test at low temperature (ca. 3 °C) showed an increase in the bending strength for almost all compositions. The grounds of this type of behavior have not been clearly stated; however, the likely causes of this are discussed.

scholarly journals An experimental investigation for the temperature effect on the bending properties of multiaxial warp-knitted composite

2020 ◽  
Vol 15 ◽  
pp. 155892502091558
Author(s):  
Xiaoping Gao ◽  
Xiaori Yang ◽  
Xianyan Wu ◽  
Pibo Ma
Keyword(s):  
Bending Strength ◽  
Bending Properties ◽  
Sem Images ◽  
Nonlinear Fitting ◽  
Bending Modulus ◽  
Ultimate Bending Strength ◽  
Different Temperatures ◽  
Bending Behavior ◽  
Fracture Morphologies ◽  
Properties Of Composites

An experimental study of bending properties of composites reinforced with triaxial and quadaxial warp-knitted glass fabrics was carried out in the 0°, 45°, and 90° directions at −30°C, 0°C, 20°C, and 40°C, respectively. The relationships between the stress–strain curves, bending strength, bending modulus, and temperature were obtained. The failure mechanisms at different temperatures were also analyzed based on the fracture morphologies and scanning electron microscope (SEM) images. The results indicated that the bending properties decrease slightly with the increase in temperature from −30°C to 20°C and decrease dramatically from 20°C to 40°C. The ultimate bending strength of triaxial and quadaxial warp-knitted composites decreases approximately 31.34% and 34.29%, respectively. In particular, the relationships between bending strength and temperature were also obtained by nonlinear fitting with the experimental data, which could be used to predict the bending behavior at different temperatures.

scholarly journals Effect of Chromium on Electrochemical and Mechanical Properties of Beta-Al2O3 Solid Electrolyte Synthesized Via a Citrate-Nitrate Combustion Method

Crystals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 987
Author(s):  
Jin Shi ◽  
Yongfei Hong ◽  
Chengfei Zhu
Keyword(s):  
Ionic Conductivity ◽  
Solid Electrolyte ◽  
Relative Density ◽  
Bending Strength ◽  
Electrochemical Impedance ◽  
Raw Materials ◽  
Combustion Method ◽  
Scanning Calorimetry ◽  
Al2o3 Phase ◽  
Precursor Powders

The beta-Al2O3 solid electrolyte doped with Chromium was synthesized via a citrate-nitrate combustion method, which started with NaNO3, LiNO3, Cr(NO3)3·9H2O, and Al(NO3)3·9H2O as the raw materials in this paper. The thermal behavior analysis, structure, and ionic conductivity of the beta-Al2O3 solid electrolyte were studied by the thermogravimetry/differential scanning calorimetry (TG/DSC), X-ray diffraction (XRD), scanning electron microscopy (SEM), and electrochemical impedance spectroscopy (EIS). Meanwhile, the relative density and bending strength of the samples were also measured. The results showed that with the appropriate Chromium doping, the calcining temperature of the precursor powders was only 1100 °C, the β″-Al2O3 phase content, bending strength, relative density, and ionic conductivity were all improved with a compact and uniform cross section micrograph. The optimized sample contained 94% of β″-Al2O3 phase and exhibited a relative density up to 98.13% of the theoretical density. In addition, it showed a good bending strength (215 MPa) and a satisficed ionic conductivity (0.110 S cm−1 at 350 °C).

Effect of Sintering Schedule to the Alloyability of FeCrAl Powder Mix Formed at above Ambient Temperature

2015 ◽  
Vol 1115 ◽  
pp. 199-202
Author(s):  
Mujibur M. Rahman ◽  
A.A.A. Talib
Keyword(s):  
Experimental Investigation ◽  
Elevated Temperature ◽  
Ambient Temperature ◽  
Axial Loading ◽  
Xrd Analysis ◽  
Compaction Process ◽  
Argon Gas ◽  
Fecral Alloy ◽  
Powder Mass ◽  
Die Compaction

This paper presents the outcomes of an experimental investigation on the effect of sintering schedule to the alloyability of FeCrAl powder mix formed through warm powder compaction process. A lab-scale uni-axial die compaction rig was designed and fabricated which enabled the compaction of powder mass at elevated temperature. Iron (Fe) powder ASC 100.29 was mechanically mixed with other alloying elements, namely chromium (Cr), and aluminum (Al) for 60 minutes and compacted at 150°C by applying 130 kN axial loading to generate green compacts. The defect-free green compacts were subsequently sintered in an argon gas fired furnace for different holding times. The sintered samples were then undergone XRD analysis. The results revealed that the alloyability of sintered products were affected by the holding time during sintering. The sample sintered at 800°C for 60 minutes showed the highest intensity of FeCrAl alloy.

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