Effects of Matrix Material Particle Size on Mullite Whisker Growth

2021 ◽  
Vol 31 (6) ◽  
pp. 313-319
Author(s):  
Jinsung Hwang ◽  
Songyul Choe
2021 ◽  
Vol 11 (14) ◽  
pp. 6265
Author(s):  
Alessandra Diotti ◽  
Giovanni Plizzari ◽  
Sabrina Sorlini

Construction and demolition wastes represent a primary source of new alternative materials which, if properly recovered, can be used to replace virgin raw materials partially or totally. The distrust of end-users in the use of recycled aggregates is mainly due to the environmental performance of these materials. In particular, the release of pollutants into the surrounding environment appears to be the aspect of greatest concern. This is because these materials are characterized by a strong heterogeneity which can sometimes lead to contaminant releases above the legal limits for recovery. In this context, an analysis of the leaching behaviour of both CDWs and RAs was conducted by applying a statistical analysis methodology. Subsequently, to evaluate the influence of the particle size and the volumetric reduction of the material on the release of contaminants, several experimental leaching tests were carried out according to the UNI EN 12457-2 and UNI EN 12457-4 standards. The results obtained show that chromium, mercury, and COD are the most critical parameters for both CDWs and RAs. Moreover, the material particle size generally affects the release of contaminants (i.e., finer particles showed higher releases), while the crushing process does not always involve higher releases than the sieving process.


2017 ◽  
Vol 140 (3) ◽  
Author(s):  
Thella Babu Rao

One of the major advantages of metal matrix composites (MMCs) is that their tailorable properties meet the specific requirements of a particular application. This paper deals with the experimental investigations done on the effects of the reinforcement particulate size and content on the Al7075/SiC composite. The composites were manufactured using stir casting technique. The effect of SiC particle size (25, 50, and 75 μm) and particulate content (5, 10, and 15 wt %) on the microstructural, mechanical properties, and wear rate of the composites was studied and the results were analyzed for varied conditions of reinforcement. Scanning electron microscope (SEM) examinations were used to assess the dispersion of SiC particles reinforced into the matrix alloy and was found with reasonably uniform with minimal particle agglomerations and with good interfacial bonding between the particles and matrix material. X-ray diffraction (XRD) analysis confirmed the presence of Al and SiC with the composite. The results of mechanical tests showed that the increasing SiC particle size and content considerably enhanced the ultimate tensile strength and hardness of the composites while the ductility at this condition was decreased. The highest ultimate tensile strength of 310 MPa and hardness of 126 BHN were observed for the composites containing 15 wt %. SiC at 75 μm. Lesser the wear resistance of the reference alloy while it was enhanced up to 40% with the composites. The wear resistance was increased up to 1200 m of sliding distance for all the composites, whereas for the composite containing 75 μm SiC particles, it was extended up to 1800 m.


2022 ◽  
pp. 1-15
Author(s):  
Lu Lee ◽  
Arash Dahi Taleghani

Summary Lost circulation materials (LCMs) are essential to combat fluid loss while drilling and may put the whole operation at risk if a proper LCM design is not used. The focus of this research is understanding the function of LCMs in sealing fractures to reduce fluid loss. One important consideration in the success of fracture sealing is the particle-size distribution (PSD) of LCMs. Various studies have suggested different guidelines for obtaining the best size distribution of LCMs for effective fracture sealing based on limited laboratory experiments or field observations. Hence, there is a need for sophisticated numerical methods to improve the LCM design by providing some predictive capabilities. In this study, computational fluid dynamics (CFD) and discrete element methods (DEM) numerical simulations are coupled to investigate the influence of PSD of granular LCMs on fracture sealing. Dimensionless variables were introduced to compare cases with different PSDs. We validated the CFD-DEM model in reproducing specific laboratory observations of fracture-sealing experiments within the model boundary parameters. Our simulations suggested that a bimodally distributed blend would be the most effective design in comparison to other PSDs tested here.


2013 ◽  
Vol 99 (6) ◽  
pp. 401-406 ◽  
Author(s):  
Daisuke Noguchi ◽  
Ryouta Ikezaki ◽  
Ko-Ichiro Ohno ◽  
Takayuki Maeda ◽  
Kouki Nishioka ◽  
...  

1991 ◽  
Vol 35 (B) ◽  
pp. 1055-1061
Author(s):  
V. V. Zagorodny ◽  
V. I. Karmanov

AbstractA new experimental calculation method for polydisperse (i.e. heterogeneous) multicomponent material analysis has been developed using the dependence of element fluorescence intensity on the particle size and its distribution in the specimen. It is shown that correction of the influence of matrix particle size is possible using this experimental calculation method. For its application, the information on particle size distribution for each of the components is sufficient. Sample preparation includes only the pelleting of specimens under standard conditions. The efficiency of the method proposed is demonstrated by the analysis of the multicomponent mixtures of welding materials.


Author(s):  
Soroor Karimi ◽  
Amir Mansouri ◽  
Siamack A. Shirazi ◽  
Brenton S. McLaury

Sand particles entrained in fluids can cause erosive wear and damage to piping materials by impacting their surfaces which could result in failure of the piping system. Several parameters have been determined to affect the erosion behavior and mechanism of solid particle erosion. Some of these parameters include surface material, particle impact speed and angle, and particle size, shape and hardness. However, the effect of particle size on the total erosion rate and local erosion pattern has not been thoroughly investigated. It has been observed that sand particles with various sizes cause different slurry erosion patterns. Changing the particle size alters the Stokes number and consequently produces different erosion patterns and magnitudes. Thus, the effects of particle size on total erosion rate and erosion pattern in a submerged slurry jet are investigated for different impingement angles. Experiments are performed on 316 stainless steel specimens for average particles sizes of 25, 75, 150, and 300 μm. The jet angle is varied to 45, 75 and 90 degrees, and the slurry jet velocity is set to 14 m/s. The erosion pattern of the specimen is examined by obtaining the 3D microscopic profile of the eroded specimen by means of an optical profiler. It is found that the erosion profile changes as the jet angle varies. It is also observed that erosion profile is significantly different for smaller particles as compared to the larger particles. Moreover, these differences become more pronounced as the jet angle decreases. The present work discusses the differences of erosion patterns produced by both large and small particles. Computational Fluid Dynamics (CFD) is also used to study the effect of particle size on particle trajectories, impact speed, and impact angle. Also, CFD results help in explaining the differences observed in the erosion profiles caused by different particle sizes.


1988 ◽  
Vol 37 (11) ◽  
pp. 607-611
Author(s):  
Kazumi MIZUKAMI ◽  
Shigeo KASAI ◽  
Naoki KASAI ◽  
Kazuhiko AMAKAWA

2019 ◽  
Vol 107 ◽  
pp. 19-23
Author(s):  
MARTA BABICKA ◽  
IZABELA RATAJCZAK ◽  
KRZYSZTOF DWIECKI

A comparison of methods for obtaining nanocellulose using acid and ionic liquid hydrolysis reactions. In this study, two methods were compared, i.e. acid hydrolysis using sulphuric acid (VI) and ionic liquid hydrolysis using 1-methyl-3-butylimidazolium chloride to obtain nanocellulose from Sigmacell Cellulose Type 20. The efficiency of both processes was tested for weight loss of the material during the reaction. The study showed that much more material can be obtained using ionic liquid hydrolysis than using acid hydrolysis. A dynamic light scattering study was performed to determine material particle size before and after these processes. Particles of nanometric size were recorded only for cellulose after the reaction with an ionic liquid. In addition, Fourier transform infrared spectroscopy was performed to determine the chemical structure of the materials tested.


2013 ◽  
Vol 15 (1) ◽  
pp. 131-139 ◽  
Author(s):  
Srimanta Sarkar ◽  
Bee Hwee Ang ◽  
Celine Valeria Liew

2011 ◽  
Vol 80-81 ◽  
pp. 221-224
Author(s):  
Xue Qing Yue ◽  
Yan Lu ◽  
Dong Hua Lu

In order to investigate the structural evolution of natural flake graphite with different particle sizes during the intercalation and exfoliation process, we used three natural graphites, 35, 50 and 80 mesh, as the raw material and investigated the characteristics of the three chemically prepared graphite intercalation compounds (GICs) of H2SO4 and the three corresponding residue GICs (RGICs). Expanded graphites (EGs) were prepared by rapidly heating the RGICs to 1000 °C in a muffle. The Results show that with decreasing the raw graphite particle size, the oxidizing reaction degree of GIC increases, but the intercalating reaction degree decreases. For RGICs, the relative ratio of RGIC phase in a sample decreases with decreasing the raw material particle size. In addition, decreasing the raw graphite particle size decreases the expanded volume of EG.


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