Effect of Particle Size of W-Brass Composite on Gamma-Ray Absorption Coefficient

2015 ◽  
Vol 754-755 ◽  
pp. 19-23
Author(s):  
Kahtan S. Mohammed ◽  
Ali Basheer Azeez ◽  
Mohd Mustafa Al Bakri Abdullah ◽  
Kamarudin Hussin ◽  
Azmi B. Rahmat

In this study, the dependence of gamma-ray absorption coefficient on amount and particle size of tungsten (W) in W-brass sintered compacts was investigated. To attain this goal, two sets of different W wt. % were prepared (W 65wt. %, W75wt. % and W85 wt. %). One set has compacts of as received powder and the other set has compacts of ball milled powder. The results showed that gamma-ray attenuation coefficient is inversely proportional to the particle size of the tested sintered compacts and directly proportional to the W content. Vickers microhardness, attenuation properties and microstructural characterization were carried out on the sintered samples. The attenuation test was conducted using gamma spectrometer with Genie 200 software. The samples of ball milled powder and of the highest volume fraction of W showed the highest hardness and attenuation values.

2011 ◽  
Vol 8 (2) ◽  
pp. 613-617 ◽  
Author(s):  
Baghdad Science Journal

In this study, dependence of gamma-ray absorption coefficient on the size of Pb particle size ranging from 200µm up to 2.5mm, using different weights of each particle size. The results show that gamma-ray attenuation coefficient is inversely proportional with the size of Pb particle size due to the reduction of the spaces between the lead particles.


2020 ◽  
Vol 108 (2) ◽  
pp. 159-164
Author(s):  
S. Z. Islami rad ◽  
R. Gholipour Peyvandi

AbstractThe ability to precisely predict the volume fraction percentage of the different phases flowing in a pipe plays an important role in the oil, petroleum and other industries. In this research, the volume fraction percentage was measured precisely in water-gasoil-air three-phase flows by using a single pencil beam gamma ray attenuation technique and multilayer perceptron (MLP) neural network. The volume fraction percentage determination in three-phase flows requires least two gamma radioactive sources with different energies while in this study, we used just a 137Cs source (with the single energy of 662 keV) and a NaI detector. Also, in this work, the MLP neural network in MATLAB software was implemented to predict the volume fraction percentage. The experimental setup provides the required data for training and testing the network. Using this proposed method, the volume fraction was predicted in water-gasoil-air three-phase flows with mean relative error percentage less than 6.95 %. Also, the root mean square error was calculated 2.60. The set-up used is simpler than other proposed methods and cost, radiation safety and shielding requirements are minimized.


Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1678 ◽  
Author(s):  
Chun Chiu ◽  
Hong-Min Huang

Mg97Zn1Y2 (at %) alloy with a long period stacking ordered (LPSO) phase has attracted a great deal of attention due to its excellent mechanical properties. It has been reported that this alloy could be fabricated by warm extrusion of rapid solidified alloy powders. In this study, an alternative route combining mechanical milling and equal channel angular pressing (ECAP) was selected to produce the bulk Mg97Zn1Y2 alloy. Microstructural characterization, mechanical properties and corrosion behavior of the ECAP-compacted alloys were studied. The as-cast alloy contained α-Mg and LPSO-Mg12Zn1Y1 phase. In the as-milled powder, the LPSO phase decomposed and formed Mg24Y5 phase. The ECAP-compacted alloy had identical phases to those of the as-milled sample. The compacted alloy exhibited a hardness of 120 HV and a compressive yield strength of 308 MPa, which were higher than those of the as-cast counterpart. The compacted alloy had better corrosion resistance, which was attributed to the reduced volume fraction of the secondary phase resulting in lower microgalvanic corrosion in the compacted alloy. The increase in Y content in the α-Mg matrix also contributed to the improvement of corrosion resistance.


1997 ◽  
Vol 61 (1) ◽  
pp. 23-26 ◽  
Author(s):  
J. C. M. Oliveira ◽  
K. Reichardt ◽  
C. M. P. Vaz ◽  
D. Swartzendruber

2018 ◽  
Vol 770 ◽  
pp. 116-125
Author(s):  
Yi Fei Luo ◽  
Yue Huang Xie ◽  
Jia Miao Liang ◽  
De Liang Zhang

Ti-6Al-4V (wt.%) alloy rods were prepared successfully using a low-cost and short powder metallurgy process that involves mixing TiH2 and Al60V40 powders, compacting the powder blend and extruding the powder compact at elevated temperatures. The microstructure and mechanical properties of Ti-6Al-4V alloy and the effects of particle size, oxygen content and heat treatment on them were investigated. The results showed that the microstructure and homogeneity of the extruded rods were strongly affected by the particle size of TiH2/Al60V40 powder blends. By changing tumbler mixing into low-energy ball milling, the TiH2/Al60V40 particle sizes decreased, and the volume fraction of undissolved V rich particles in the microstructure of the extruded rod substantially decreased from 8.6% to zero. High yield strength and ultimate tensile strength of 1154 and 1353 MPa respectively with a moderate elongation to fracture of 3.6% are achieved with the Ti-6Al-4V rod prepared by using the powder blend. The extruded Ti-6Al-4V rod prepared using the ball milled powder had a very high strength, but limited ductility due to a high oxygen content. Solution treatment and aging slightly increase the strength of Ti-6Al-4V rods at the cost of dramatic decrease of ductility.


Soil Science ◽  
1999 ◽  
Vol 164 (6) ◽  
pp. 403-410 ◽  
Author(s):  
Carlos Manoel Pedro Vaz ◽  
João de Mendonça Naime ◽  
Álvaro Macedo

Sign in / Sign up

Export Citation Format

Share Document