Effect of Jet Grading Technology on the Properties and Structural Characteristics of Tungsten Products

2021 ◽  
Vol 1035 ◽  
pp. 273-277
Author(s):  
Yu Qing Zhang ◽  
Lu Yan Wang ◽  
Cao Bing Li ◽  
Shan Yu Liu

Jet grading technology is an efficient process in different industries. In this research, tungsten powder with different particle size distribution was used as a raw material to produce tungsten products via isostatic pressing as well as sintering. The mechanism of jet grading and the morphology and particle size distribution of different precursors were analyzed. The results showed that jet grading technology had remarkable effect on tungsten powder classification. The appropriate grading treatment was helpful to the formation of tungsten products with high performance. After jet grading and the following process like pressing and sintering, the tungsten products with better properties were manufactured which was used fischer particle size of 3.0~3.5μm as the raw material. The obtained products’ density was 18.77g/cm3 and its hardness was 372.15HV0.3.

2011 ◽  
Vol 127 ◽  
pp. 101-104
Author(s):  
Xiao Ming Fu

Violet tungsten oxide is prepared with pure ammonium paratungstate in the argon gas. Tungsten powder is obtained with violet tungsten oxide through deoxidation in the hydrogen gas (Rate of purity: 99.99 %, dew point: -40 °C), and tungsten powder is oxidized in the air. Tungsten oxide is reduced with tungsten powder in the hydrogen gas. The samples are characterized with the laser particle size distribution measuring instrument and field-emission scanning electron microscope. The results show that ultrafine tungsten powder is obtained through circulatory oxidation twice and reduction three times. The percentage of the particle size distribution of ultrafine tungsten powder is 95.73 % between 0.1 μm and 1.0 μm.


2014 ◽  
Vol 968 ◽  
pp. 40-43 ◽  
Author(s):  
Cong Xue Tian

Short sulfate process was developed to produce rutile TiO2 white pigment by using low concentration industrial TiOSO4 solution as raw material via self-generated seeded thermal hydrolysis route. The concentration of TiOSO4 solution had significantly influenced the structure and pigment properties of rutile TiO2 white pigment. The samples were characterized by XRD, particle size distribution and pigment properties test. Appropriate concentration of TiOSO4 was beneficial to promoting hydrolysis process in a proper way and obtaining favorable structure and high quality white pigment. The optimized concentration of TiOSO4 solution was of 191.20 g/L.


Author(s):  
Adam J. Cooper ◽  
Olivia C. G. Tuck ◽  
Samuel A. J. Armson ◽  
Michael Preuss

Abstract If advanced manufacturing technologies are to be adopted over conventional manufacturing processes in the nuclear industry — the most regulatory challenging industry — rigorous fundamental studies that develop underpinning knowledge, materials performance data, and predictive capabilities are essential. Herein we have employed the use of electron backscatter diffraction (EBSD) and 3D X-ray computed tomography (XCT) to characterize microstructure evolution and porosity consolidation during the early stages of powder metallurgy hot isostatic pressing (PM-HIP). The data herein highlight the mechanisms through which the powder particle size distribution encourages localized plastic deformation and subsequent microstructural recrystallization of Type 316L stainless steel; the effect of powder particle size distribution on the rate of porosity consolidation is also discussed. Specifically, we have determined the temperature and pressure conditions that are required to initiate dynamic recrystallization during HIP, and explain how this is influenced by the powder particle size distribution.


2017 ◽  
Vol 898 ◽  
pp. 1717-1723 ◽  
Author(s):  
Xue Mei Yi ◽  
Shota Suzuki ◽  
Xiong Zhang Liu ◽  
Ran Guo ◽  
Tomohiro Akiyama

Combustion synthesis (CS) of β-SiAlON was conducted using a 3D ball mill, with a focus on the effect of the 2D/3D ball mill premixing conditions on the CS raw material particle size as well as on the yield and grain shape of the final products. The results showed that the particle size distribution of the raw materials was significantly affected by the premixing conditions. Various particle sizes and particle size distributions could easily be obtained by using a 3D mill instead of a 2D mill due to the complex biaxial rotation movement of 3D milling. The particle size was more sensitive to the rotation ratio (vertical spin/horizontal spin, Vv/Vh) than the rotation rate when using 3D milling. Finally, β-SiAlON with less than 5 mass% unreacted Si was obtained using premix milling conditions of 135×200 [vertical spin (rpm) × horizontal spin (rpm)]. The grain shapes of the final products were clearly influenced by the particle size distribution of the raw mixtures.


2014 ◽  
Vol 700 ◽  
pp. 205-210 ◽  
Author(s):  
Ye Lv ◽  
Xiao Yan Guan ◽  
Ben Qing Ruan ◽  
Yan Wei Wang

Soil particle size distribution (PSD) is one of the most important physical properties of soil due to its strong influence on hydraulic characteristic, fertility condition and erosion of soil, etc. Sewage irrigation causes the differences in soil PSD. Thus, there may be massive organic contaminants and suspended particles in soil. In this paper, the frequency and multifractal necessity of soil PSD under sewage irrigation in different years were analyzed. Soil PSD demonstrates a heterogeneous characteristic under sewage irrigation, and this heterogeneity can be characterized using the multifractal technique, which calculates the multifractal spectrum parameters. The results showed that the width of multifractal spectrum ∆α is directly proportional to clay content; a remarkable effect of sewage irrigation on multifractal parameters was observed. The soil structure quality decreased with increasing sewage irrigation years. However, the soil structure improved when the soil was irrigated with freshwater for a long period after sewage irrigation. Therefore, multifractal parameters may be potential indicators for the physical property and quality of soil.


2020 ◽  
Vol 24 (2) ◽  
pp. 45-54
Author(s):  
Dariusz Dziki ◽  
Wojciech Tarasiuk ◽  
Grzegorz Łysiak ◽  
Paweł Jochymek

AbstractThe aim of this work was to study the particle size distribution of micronized oat bran. An impact classified mill was used to pulverizing. Before the pulverizing raw material was sterilized using overheated steam at 150°C during 3.5 min. The moisture of bran after sterilization decreased from 7.2 to about 3.9%. Five speeds of the rotor disc were used: 2600, 2970, 3340, and 3710 rpm. For each speed of the rotor disc the following speeds of classifier wheel were applied: 480, 965, 1450, 1930, 2410 and 2890 rpm. The particle size distribution of oat bran layer was measured by laser light scattering. Moreover, the sense of touch of coarse particles of micronized oat bran on a tongue was assessed according to five point scale. The largest fragmentation of the oat bran was obtained at a disc speed of 3710 rpm and at a classifier rotation speed of 1930 rpm, whereas the most coarse particles were obtained when these parameters were 3340 rpm and 480 rpm, respectively. On the other hand, the highest uniformity in size of particles in size was observed when the lowest speed of disc and classifier were used. Moreover, for the most samples the pulverized particles of oat bran were almost not discernible on tongue.


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