Layer-by-layer laser synthesis of composite ceramics in the system Al-Ti-Y-O

2014 ◽  
Vol 1611 ◽  
pp. 55-60
Author(s):  
M. Vlasova ◽  
M. Kakazey ◽  
E.A. Juarez-Arellano ◽  
P.A. Márquez Aguilar ◽  
R. Guardian Tapia ◽  
...  
Keyword(s):  
Phase Composition ◽  
Laser Treatment ◽  
Layer By Layer ◽  
Composite Ceramics ◽  
Powder Mixtures ◽  
Laser Synthesis ◽  
Additional Heating

ABSTRACTThe phase composition and the microstructure of multilayer ceramics synthesized by directed laser treatment of ternary powder mixtures of Al2O3–TiO2–Y2O3 have been studied. It is established that at R = 2.34 (where R is TiO2/Y2O3 in mol %) the main phases observed are Y2Ti2O7, α-Al2O3 and a little amount of β-Al2TiO5. The content of the formed phases is determined by the composition of the initial mixtures. The texture of the surface and the microstructure of the formed ceramics depend on the α-Al2O3 and Y2Ti2O7 content. Increasing the content of alumina in the initial mixtures, the surface of the ceramics is saturated by α-Al2O3 crystallites. When a multi-layer synthesis is realized, the Y2Ti2O7 phase is concentrated at the boundary between the two adjacent layers (top and bottom). In the underlying layer, the growth of the corundum crystallites is prolonged due to the additional heating.

Laser Synthesis Features of Composite Ceramics Y3Al5O12-Y2Ti2O7-Al2O3-Al2TiO5

2014 ◽  
Vol 88 ◽  
pp. 74-79 ◽  
Author(s):  
P.A. Márquez Aguilar ◽  
M. Vlasova ◽  
S. Lakiza ◽  
M. Kakazey ◽  
A. Bykov ◽  
...  
Keyword(s):  
Phase Diagram ◽  
Laser Treatment ◽  
Binary Mixtures ◽  
Phase Formation ◽  
Ternary Mixtures ◽  
Composite Ceramics ◽  
Laser Synthesis

The effect of directed laser treatment on the compacted binary mixtures Al2O3–Y2O3, Y2O3–TiO2, Al2O3–TiO2 and ternary mixtures Al2O3−Y2O3−TiO2 was investigated. It was shown that phase formation occurs within the framework of binary mixtures Al2O3–Y2O3, Y2O3–TiO2, Al2O3–TiO2 and is accompanied by the formation of Y3Al5O12, Y2Ti2O7 and Al2TiO5 compounds. The set of phases and microstructures of generated ceramics depend on Al2O3 content and TiO2/Y2O3 ratio in initial mixtures. Basing in the obtained results the tentative phase diagram for the Al2O3–Y2O3−TiO2 system was constructed.

Surface changes in Al2O3–base composite ceramics under action of laser treatment

2019 ◽  
Vol 45 (5) ◽  
pp. 5454-5466 ◽  
Author(s):  
M. Vlasova ◽  
M. Kakazey ◽  
A. Castro Hernandez ◽  
P.A. Márquez Aguilar ◽  
R. Guardian Tapia ◽  
...  
Keyword(s):  
Laser Treatment ◽  
Composite Ceramics ◽  
Base Composite ◽  
Surface Changes

PHASE COMPOSITION STABILITY OF NANOSTRUCTURED COMPOSITE CERAMICS BASED ON CaO–ZrO2 UNDER HYDROTHERMAL IMPACT

2019 ◽  
Vol 14 (3-4) ◽  
pp. 125-131
Author(s):  
A. A. Dmitrievskiy ◽  
D. G. Zhigacheva ◽  
N. Yu. Efremova ◽  
A. V. Umrikhin
Keyword(s):  
Phase Composition ◽  
Composite Ceramics ◽  
Nanostructured Composite

Effects of Mn Doping on Dielectric Properties of BSTN Ceramics

2008 ◽  
Vol 368-372 ◽  
pp. 72-74
Author(s):  
Xin Cheng ◽  
Zong Hui Zhou
Keyword(s):  
Phase Transition ◽  
Phase Composition ◽  
Transition Temperature ◽  
Dielectric Properties ◽  
Phase Transition Temperature ◽  
Tungsten Bronze ◽  
Dielectric Constants ◽  
Composite Ceramics ◽  
Mn Doping ◽  
Applied Frequency

The effects of Mn doping on the phase composition and dielectric properties of (1-x)BaO·xSrO·0.7TiO2·0.3Nb2O5 (BSTN) composite ceramics was investigated. The results showed that the dielectric constants of 0.7BaO·0.3SrO·(0.7-z)TiO2·0.3Nb2O5·zMnO2 (BSTNM) composite ceramics basically decreases as the content of doped MnO2 increases at the same applied frequency, while tanδ decreases when value z≤0.01 but increases when value z>0.01. The phase transition temperature of tungsten bronze phase in BSTNM composite ceramics increases with the increase of value z.

Phase transformations on the surface of YAG composite ceramics under the action of directed laser treatment

2016 ◽  
Vol 377 ◽  
pp. 416-425 ◽  
Author(s):  
M. Vlasova ◽  
P.A. Márquez Aguilar ◽  
A. Escobar Martinez ◽  
M. Kakazey ◽  
R. Guardian Tapia ◽  
...  
Keyword(s):  
Phase Transformations ◽  
Laser Treatment ◽  
Composite Ceramics

Effect of Sr/Ba Ratio on Dielectric Properties of BSTN Ceramics

2007 ◽  
Vol 336-338 ◽  
pp. 125-128 ◽  
Author(s):  
Zong Hui Zhou ◽  
Xin Cheng ◽  
Pi Yi Du ◽  
Jun Chang ◽  
Shi Feng Huang ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Phase Composition ◽  
Dielectric Properties ◽  
Perovskite Phase ◽  
Tungsten Bronze ◽  
Dielectric Constants ◽  
Composite Ceramics ◽  
Impedance Analyzer ◽  
Applied Frequency ◽  
Two Phases

The phase composition of (1-x)BaO·xSrO·0.7TiO2·0.3Nb2O5 (BSTN) composite ceramics was analyzed by XRD, and the effect of Sr/Ba ratio on the dielectric properties of BSTN was investigated by impedance analyzer. The results showed that any sample with different x value contained two phases-the perovskite phase and the tungsten bronze phase. The dielectric constants of BSTN basically decreased while the tanδ increased with the increase in x value. Both dielectric constant and tanδ decreased with the applied frequency increased for the same x value. There were two Curie points for BSTN composite ceramics. The first one belonging to the perovskite phase decreased with the increase in x value, but the second one belonging to the tungsten bronze phase kept almost constant at about 300°C.

scholarly journals Microstructure and properties of the mullite‒ZrO2(Y2O3)‒Si3N4-composite ceramics sintered in different ways

2018 ◽  
pp. 49-54
Author(s):  
G. Sedmale ◽  
L. Grasse ◽  
I. Zalite ◽  
N. Zhilinska ◽  
Ya. Rodriges
Keyword(s):  
Phase Composition ◽  
Comparative Analysis ◽  
Conventional Method ◽  
Elasticity Modulus ◽  
Defect Formation ◽  
Strength Properties ◽  
Composite Ceramics ◽  
Ceramic Samples ◽  
Spark Plasma ◽  
Plasma Methods

The research objective was to investigate the packing degree, phase composition, microstructure and some other properties of the mullite‒ZrO2composite ceramics with the Si3N4addition sintered in different ways, such as: by the conventional method, by the spark-plasma method, and both in the microwave and solar ovens. The comparative analysis was carried out for the strength properties (these were the ultimate compressing strength and the elasticity modulus) for the ceramic samples which had been sintered by means of the conventional and of the spark-plasma methods. Some reasons for the defect formation in the samples after their sintering in the microwave and solar ovens were mentioned.Ill.8. Ref. 10. Tab. 2.

scholarly journals Calcium Phosphate Powder Synthesized from Calcium Acetate and Ammonium Hydrophosphate for Bioceramics Application

Ceramics ◽  
2018 ◽  
Vol 1 (2) ◽  
pp. 375-392 ◽  
Author(s):  
Tatiana Safronova ◽  
Valery Putlayev ◽  
Yaroslav Filippov ◽  
Tatiana Shatalova ◽  
Evgeny Karpushkin ◽  
...  
Keyword(s):  
Phase Composition ◽  
Calcium Phosphate ◽  
Room Temperature ◽  
Calcium Acetate ◽  
Molar Ratio ◽  
Composite Ceramics ◽  
Phosphate Powder ◽  
Starting Solution ◽  
By Products ◽  
Ammonium Hydrophosphate

Calcium phosphate powder was synthesized at room temperature from aqueous solutions of ammonium hydrophosphate and calcium acetate without pH adjusting at constant Ca/P molar ratio 1.5. Phase composition of the as-synthesized powder depended on the precursors concentration: At 2.0 M of calcium acetate in the starting solution, poorly crystallized hydroxyapatite was formed, 0.125 M solution of calcium acetate afforded brushite, and the powders synthesized from 0.25–1.0 M calcium acetate solutions were mixtures of the mentioned phases. Firing at 1100 °C led to complete elimination of the reaction by-products, yet the phase composition of the annealed compacted samples was the following: When 2.0 M solution of calcium acetate was used, the obtained ceramics consisted of β-Ca3(PO4)2, whereas at 0.125 to 1.0 M of calcium acetate, the ceramics was a mixture of β-Ca3(PO4)2 and β-Ca2P2O7. Synthesized calcium phosphate powders can be used as the powdered precursors for biocompatible bioresorbable composite ceramics production.

Research on Properties of AlN-Mo Composite Ceramic

2012 ◽  
Vol 482-484 ◽  
pp. 1695-1698 ◽  
Author(s):  
Jie Kang ◽  
Gui Xia Dong ◽  
Qiu Xiang Liu
Keyword(s):  
Thermal Conductivity ◽  
Dielectric Constant ◽  
Phase Composition ◽  
Composite Ceramic ◽  
Experimental Results ◽  
Composite Ceramics ◽  
Sintering Additives ◽  
Caco3 Content ◽  
Caf2 Content

With CaF2 and CaCO3 as sintering additives, AlN-Mo composite was prepared using hot pressed sintering technique. The phase composition and morphology of AlN-Mo composite ceramics were analyzed using XRD and SEM, respectively. The experimental results show that when CaF2 and CaCO3 additives is in a range of 1~3wt%, the thermal conductivity AlN-Mo composites increases with increasing of the CaF2 content; With the increasing of CaCO3 content, first increases and then decreases. Sintering additives in a certain type and content, the thermal conductivity of AlN-Mo composite ceramics with 20 vol% Mo is higher than containing 18 vol% Mo. The dielectrical property of AlN-Mo composite ceramics was also discussed. The addition of CaF2 can decrease the dielectric constant of AlN-Mo composite ceramics.

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