Wyniki wyszukiwania - BazTech

Ograniczanie wyników

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych: cyrkonia

Sortuj według:

Ogranicz wyniki do:

Investigation the effect addition of nano Al2O3 on microstructure of Yttria tetragonal Zirconia polycrystalline ceramic

Alshaibani I.J.

Archives of Materials Science and Engineering

2021

Vol. 107, nr 2

49--55

Purpose: This research aimed to prepare tetragonal zirconia polycrystals powder by coprecipitation method and study effects of addition of different amounts of nano Al2O3 (1, 2 and 4) wt.% on its microstructure and mechanical properties of (5Y-TZP) composite. Design/methodology/approach: The powder was uniaxial pressed at a pressure of 150 MPa and held for 60 s, and sintered at the 1500°C, held for two hours and then cooling down at 5°C/min to room temperature. Microhardness and fracture toughness tests were utilized to evaluate the mechanical properties of yttria tetragonal zirconia polycrystal composite. The microstructure has been observed using field emission scanning electron microscopy(FESEM). Findings: The results showed an addition of nano Al2O3 has a great influence on hardness and microstructure, the increase in Vicker's microhardness of composite samples with the increase in the nano Al2O3 wt.% and microstructure were characterized with homogeneous zirconia distribution, grain growth destruction with the increasing percentage of nano Al2O3. The most important influence is the enhancing of the densification process as the porosity decreased. The highest hardness and maximum fracture toughness were recorded at 4 wt.% nano Al2O3. Research limitations/implications: Ceramic matrix composites are developed to overcome the brittleness of ZrO2 and the low toughness of alumina by formation, a large difference of elastic behavior between matrix and particles(dispersion phase )which disturbs the stress field as a dislocation comes near a particle. Practical implications: Zirconia has mechanical properties similar to those of stainless steel. Yttria-stabilized tetragonal Zirconia (Y-TZP) is growing used in dentistry due to its good mechanical properties such as hardness and fracture toughness. Thus, controlling of microstructure by adding nanoalumina plays an important role in enhancing these properties. Originality/value: Study the adding bitty percentage from nano alumina on microstructure and mechanical properties of (5Y-TZP) ceramic.

Synthesis and Characterization of New Refractory Coatings Based on Talc, Cordierite, Zircon and Mullite Fillers for Lost Foam Casting Process

Prstić A., Aćimović-Pavlović Z., Terzić A., Pavlović L.

Archives of Metallurgy and Materials

2014

Vol. 59, iss. 1

89--95

Refractory coatings based on different refractory fillers (talc, cordierite, zircon and mullite) for application in Lost Foam casting process were investigated. Design and optimization of the coatings composition with controlled, rheological properties included, and consequently synthesis were achieved by application of different coating components, namely different suspension agents and fillers and by alteration of the coating production procedure. Morphologic and microstructural analysis of fillers was carried out by means of scanning electronic microscope. X-ray diffraction analysis by means of X-ray diffractometer was applied in determination and monitoring the phase composition changes of the refractory fillers. An analysis of the particle size and shape was carried out by means of the PC software application package OZARIA 2.5. To assess the effects of application of individual refractory coatings, a detailed investigation of structural and mechanical properties of the moldings obtained was performed. Highlight was placed on revealing and analyzing surface and volume defects present on moldings. Radiographic molding tests were carried out by means of the X-ray device SAIFORT type-S200. Attained results are essential for the synthesis of refractory coatings based on high-temperature fillers and their applications in Lost Foam casting process for manufacturing of moldings with in-advance-set properties.

W pracy przedstawiono wyniki badań materiałów wysokotemperaturowych - powłok ogniotrwałych na bazie talku, kordierytu. cyrkonii i mulitu, które są stosowane w procesie odlewania metodą piany traconej. Projektowanie i optymalizację składu powłoki o kontrolowanych właściwościach teologicznych, a następnie syntezę osiągnięto poprzez zastosowanie różnych skład- ników powłok, tj. różnych stabilizatorów zawiesiny i wypełniaczy oraz poprzez zmiany w procesie produkcji powłok. Analizę morfologiczną i mikrostruktura!ną wypełniaczy przeprowadzono za pomocą elektronowego mikroskopu skaningowego. Analizę dyfrakcji promieni rentgenowskich zastosowano do określania i monitorowania zmian składu fazowego wypełniaczy ognio- trwałych. Analizę wielkości i kształtu cząstek przeprowadzono za pomocą pakietu oprogramowania użytkowego PC OZARIA 2.5. Żeby ocenić skutki stosowania poszczególnych powłok ogniotrwałych, przeprowadzono szczegółowe badania właściwości strukturalnych i mechanicznych otrzymanych form. Nacisk został położony na ujawnienie i analizę defektów powierzchni i objętości obecnych w formach. Radiograficzne testy formowania przeprowadzono za pomocą urządzenia SAJFORT typu S200. Uzyskane wyniki są niezbędne do syntezy powłok ogniotrwałych w oparciu o wysokotemperaturowe wypełniacze i ich zastosowań w procesie odlewania metodą piany traconej do produkcji form o z góry ustalonych właściwościach.