scholarly journals Procedure and Installation for Determining the Filtering Capacity

2021 ◽  
Vol 343 ◽  
pp. 03011
Author(s):  
Sorin Butuc (Anghel) ◽  
Simona Matei ◽  
Maria Stoicanescu ◽  
Aurel Crişan

The paper presents a method and an installation for determining the filtration capacity of filters made of composite materials with ceramic matrices. Applicable to fluid media (liquid, gaseous) the process is based on generating a pressure gradient in the filter area. The pressure difference between the two sides of the filter determines the passage of the fluid through the filter and its retention of the suspended particles. The process allows the testing of filters with a great diversity regarding the nature of the materials from which they are made, respectively their geometry and dimensions. In the present experiment, filters made of ceramic composite materials based on bentonite reinforced with SiC type ceramic powders and Al type metal powders were tested. From these materials were made cylindrical filters (diameters of 16 mm and length of 15 mm), which, after sintering at a temperature of 1250°C, were tested on the installation, for filtering rainwater samples. The determinations made highlighted a good ability of the filter to retain suspended particles in the water.

2019 ◽  
Vol 118 (4) ◽  
pp. 159-168 ◽  
Author(s):  
Alejandro Carrasco-Pena ◽  
Ryan Jordan ◽  
Jessica Dieguez ◽  
Arturo Coronado-Rodríguez ◽  
Veli B. Ozdemir ◽  
...  

Nanomaterials ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 370 ◽  
Author(s):  
Bogdan Stefan Vasile ◽  
Alexandra Catalina Birca ◽  
Vasile Adrian Surdu ◽  
Ionela Andreea Neacsu ◽  
Adrian Ionut Nicoară

This paper is focused on the basic properties of ceramic composite materials used as thermal barrier coatings in the aerospace industry like SiC, ZrC, ZrB2 etc., and summarizes some principal properties for thermal barrier coatings. Although the aerospace industry is mainly based on metallic materials, a more attractive approach is represented by ceramic materials that are often more resistant to corrosion, oxidation and wear having at the same time suitable thermal properties. It is known that the space environment presents extreme conditions that challenge aerospace scientists, but simultaneously, presents opportunities to produce materials that behave almost ideally in this environment. Used even today, metal-matrix composites (MMCs) have been developed since the beginning of the space era due to their high specific stiffness and low thermal expansion coefficient. These types of composites possess properties such as high-temperature resistance and high strength, and those potential benefits led to the use of MMCs for supreme space system requirements in the late 1980s. Electron beam physical vapor deposition (EB-PVD) is the technology that helps to obtain the composite materials that ultimately have optimal properties for the space environment, and ceramics that broadly meet the requirements for the space industry can be silicon carbide that has been developed as a standard material very quickly, possessing many advantages. One of the most promising ceramics for ultrahigh temperature applications could be zirconium carbide (ZrC) because of its remarkable properties and the competence to form unwilling oxide scales at high temperatures, but at the same time it is known that no material can have all the ideal properties. Another promising material in coating for components used for ultra-high temperature applications as thermal protection systems is zirconium diboride (ZrB2), due to its high melting point, high thermal conductivities, and relatively low density. Some composite ceramic materials like carbon–carbon fiber reinforced SiC, SiC-SiC, ZrC-SiC, ZrB2-SiC, etc., possessing low thermal conductivities have been used as thermal barrier coating (TBC) materials to increase turbine inlet temperatures since the 1960s. With increasing engine efficiency, they can reduce metal surface temperatures and prolong the lifetime of the hot sections of aero-engines and land-based turbines.


1991 ◽  
Vol 113 (1) ◽  
pp. 51-59 ◽  
Author(s):  
S. Majumdar ◽  
J. P. Singh ◽  
D. Kupperman ◽  
A. D. Krawitz

An experimental neutron diffraction technique was used to measure residual strains that developed in multiphase composite materials during postfabrication cooling as a result of thermal expansion mismatch or volume expansion due to change in crystal structure. The reinforcement geometries that were studied include unidirectional fibers, randomly oriented single crystal whiskers, and equiaxed particles. Both metal and ceramic matrices and reinforcements were considered. In some cases, the measured data compared fairly well with predictions based on simple elastic models. In other cases, either creep was shown to relax the residual strains during cooling, or the interpretation of the measured data contained uncertainties due to texture in the samples or lack of a clearly defined crystal structure for the reinforcement phase.


Ionics ◽  
2013 ◽  
Vol 19 (12) ◽  
pp. 1751-1760 ◽  
Author(s):  
A. Rajani Malathi ◽  
Ch. Sameera Devi ◽  
G. S. Kumar ◽  
M. Vithal ◽  
G. Prasad

2008 ◽  
Vol 59 ◽  
pp. 87-91 ◽  
Author(s):  
K. Mergia ◽  
Volker Liedtke ◽  
T. Speliotis ◽  
G. Apostolopoulos ◽  
S. Messoloras

The use of ceramic composite materials in aerospace applications requires the development of oxidization protection coatings which can withstand very high temperatures. HfO2 is a promising material as a high temperature oxidization protective layer. HfO2 coatings have been deposited by radiation frequency magnetron sputtering all over the surface of SiC substrates and were tested under re-entry conditions. Also their oxidization resistance in air in the temperature range 1100 to 1450°C has been examined. The coatings were found to be stable and well-adhering to the substrate even after 100 re-entry cycles. No oxidization of the underlying SiC structure is observed. Re-entry and oxidization tests result in the formation of HfSiO4 at the HfO2/SiC interface, which further promotes their oxidization resistance.


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