scholarly journals Influence of Cooling Rate on Microsegregation Behavior of Magnesium Alloys

2014 ◽  
Vol 2014 ◽  
pp. 1-18 ◽  
Author(s):  
Md. Imran Khan ◽  
Ahmad O. Mostafa ◽  
Mohammad Aljarrah ◽  
Elhachmi Essadiqi ◽  
Mamoun Medraj
Keyword(s):  
Particle Size ◽  
Cooling Rate ◽  
Magnesium Alloys ◽  
Phase Particle ◽  
Secondary Phase ◽  
Composition Analysis ◽  
Minimum Concentration ◽  
Secondary Phase Particle ◽  
Electron Microscopes ◽  
Area Percentage

The effect of cooling rate on microstructure and microsegregation of three commercially important magnesium alloys was investigated using Wedge (V-shaped) castings of AZ91D, AM60B, and AE44 alloys. Thermocouples were distributed to measure the cooling rate at six different locations of the wedge casts. Solute redistribution profiles were drawn based on the chemical composition analysis obtained by EDS/WDS analysis. Microstructural and morphological features such as dendrite arm spacing and secondary phase particle size were analyzed using both optical and scanning electron microscopes. Dendritic arm spacing and secondary phase particle size showed an increasing trend with decreasing cooling rate for the three alloys. Area percentage of secondary phase particles decreased with decreasing cooling rate for AE44 alloy. The trend was different for AZ91D and AM60B alloys, for both alloys, area percentage of β-Mg17Al12 increased with decreasing cooling rate up to location 4 and then decreased slightly. The tendency for microsegregation was more severe at slower cooling rates, possibly due to prolonged back diffusion. At slower cooling rate, the minimum concentration of aluminum at the dendritic core was lower compared to faster cooled locations. The segregation deviation parameter and the partition coefficient were calculated from the experimentally obtained data.

Effects of Secondary Phase Particle Dissolution on the In-Reactor Performance of BWR Cladding

2011 ◽  
Vol 8 (2) ◽  
pp. 103025 ◽  
Author(s):  
S. Valizadeh ◽  
G. Ledergerber ◽  
S. Abolhassan ◽  
D. Jädernäs ◽  
M. Dahlbäck ◽  
...  
Keyword(s):  
Phase Particle ◽  
Secondary Phase ◽  
Reactor Performance ◽  
Secondary Phase Particle ◽  
Particle Dissolution

Effects of Secondary Phase Particle Dissolution on the In-Reactor Performance of BWR Cladding

2011 ◽  
pp. 729-753 ◽  
Author(s):  
S. Valizadeh ◽  
G. Ledergerber ◽  
S. Abolhassani ◽  
D. Jädernäs ◽  
M. Dahlbäck ◽  
...  
Keyword(s):  
Phase Particle ◽  
Secondary Phase ◽  
Reactor Performance ◽  
Secondary Phase Particle ◽  
Particle Dissolution

Effects of Secondary Phase Particle Dissolution on the In-Reactor Performance of BWR Cladding

2011 ◽  
pp. 729-753 ◽  
Author(s):  
S. Valizadeh ◽  
G. Ledergerber ◽  
S. Abolhassani ◽  
D. Jädernäs ◽  
M. Dahlbäck ◽  
...  
Keyword(s):  
Phase Particle ◽  
Secondary Phase ◽  
Reactor Performance ◽  
Secondary Phase Particle ◽  
Particle Dissolution

The Hayashi-nishi Method for Measurement of Mixing:Computer-Generated Morphologies and Impact-Modified Polymers

1998 ◽  
Vol 4 (S2) ◽  
pp. 830-831
Author(s):  
M. R. Tant ◽  
D. B. Calvert ◽  
P. S. Wehner
Keyword(s):  
Phase Particle ◽  
Secondary Phase ◽  
The State ◽  
Polymeric Matrix ◽  
Core Shell ◽  
Secondary Phase Particle ◽  
Modified Polymers ◽  
Impact Modifier ◽  
Image Position ◽  
The Impact

In this work we apply the Hayashi-Nishi method for quantitatively analyzing the state of mixing of a secondary component in a polymeric matrix. We (1) evaluate the method using computer-generated morphologies and (2) compare the state of mixing of a core-shell impact modifier in polymers having differing affinity for the impact modifier. In the Hayashi-Nishi method two numbers, related to dispersion and distribution, are required to quantify the state of mixing of a secondary phase in a polymeric matrix. The 5-parameter in the Hayashi-Nishi method is defined asThe Ai's are the areas of each individual secondary phase particle or aggregate and nis the number of such particles in the image. S is related to the size distribution of these aggregate areas and is a measure of dispersion of the secondary phase in that particular image.

Stacking faults in Zr(Fe, Cr)2 Laves structured secondary phase particle in Zircaloy-4 alloy

Nanoscale ◽  
2018 ◽  
Vol 10 (5) ◽  
pp. 2249-2254 ◽  
Author(s):  
Chengze Liu ◽  
Geping Li ◽  
Fusen Yuan ◽  
Fuzhou Han ◽  
Yingdong Zhang ◽  
...  
Keyword(s):  
Formation Mechanism ◽  
Phase Particle ◽  
Stacking Faults ◽  
Secondary Phase ◽  
Secondary Phase Particle

Understanding the formation mechanism of stacking faults in secondary phase particles.

Electroacoustic Study of n-Hexadecane/Water Emulsions

2001 ◽  
Vol 54 (8) ◽  
pp. 503 ◽  
Author(s):  
Linggen Kong ◽  
James K. Beattie ◽  
Robert J. Hunter
Keyword(s):  
Particle Size ◽  
Zeta Potential ◽  
Volume Fraction ◽  
Sodium Dodecyl ◽  
Surfactant Solution ◽  
Minimum Size ◽  
Water Mixture ◽  
Concentrated Suspensions ◽  
Minimum Concentration ◽  
Median Diameter

n-Hexadecane-in-water emulsions were investigated by electroacoustics using a prototype of an AcoustoSizer-II apparatus. The emulsions were formed by passing the stirred oil/water mixture through a homogenizer in the presence of sodium dodecyl sulfate (SDS) at natural pH (6–7). With increasing oil-volume fraction, the particle size increased linearly after 5 and also after 20 passages through the homogenizer, suggesting that surface energy was determining particle size. For systems in which the surfactant concentration was limited, the particle size after 20 passages approached the value dictated by the SDS concentration. With ample surfactant present, the median diameter was a linear function of the inverse of the total energy input as measured by the number of passes. There was, however, a limit to the amount of size reduction that could be achieved in the homogenizer, and the minimum size was smaller at smaller volume fractions. Dilution of the emulsion with a surfactant solution of the same composition as the water phase had a negligible effect on the particle size and changed the zeta potential only slightly. This confirms results from previous work and validates the equations used to determine the particle size and zeta potential in concentrated suspensions. The minimum concentration of SDS that could prevent the emulsion from coalescing for the system with 6% by volume oil was 3 mM. For this dilute emulsion, the particle size decreased regularly with an increase in SDS concentration, but the magnitude of the zeta potential went through a strong maximum at intermediate surfactant concentrations.

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