Elaboration et caractérisation de céramiques structurales à base de matériaux locaux destinés aux mitigeurs de robinets

Abstract

Through this study, we characterized ceramic discs from an imported commercial cartridge, used by SANIAK-BCR valves (Setif). We used the following techniques: X-ray diffraction (XRD) which allowed us to identify the phases present (alumina, spinel). The analysis of the microstructure by SEM led to the knowledge of the size of the grains and the pores. The instrumented indentation technique allowed the determination of hardness (~ 12 GPa), toughness (~ 4 MPa.√m), the determination of the Poisson's ratio and the elastic modulus (~300GPa) were made by Ultrasonic Resonance Spectroscopy. The bulk density (~ 3.6 g / cm3) was measured by Archimedes method. The surface finish was studied with an atomic force microscope (AFM). We have also produced a mullite from Algerian kaolins (DD1, DD2, and DD3) located in Djebel Debbagh (North-East of Algeria) and a commercial alumina trihydrate. The aluminum tri-hydroxide Al (OH)3 used (marketed by sigma-Aldrich) has an average size D50 = 6 µm. The crude kaolins are mixed in three compositions referenced M1, M2 and M3, then reduced to an average particle size of D50 = 2 μm. To achieve this grain size, we used different grinding techniques. The starting powders were analyzed with different techniques (TDA / TGA, XRD, SEM, etc.). Next, we shaped the samples by uniaxial pressing. The sintering conditions (temperature and holding time) were varied. The samples produced under different conditions were characterized. The essential properties measured and studied are: microstructure (grain shape (acicular), grain size, density (2.65 ~ 3.1 g / cm3), porosity (27-2%), mechanical resistance such as hardness (9.3 ~ 15.5GPa) and toughness. The tribological properties (friction coefficient) as well as the morphology of the tracks. The results obtained were analyzed and discussed.