Fabrication of Al2O3-ZrO2~Ni Functionally Graded Pipes

2005 ◽  
Vol 492-493 ◽  
pp. 69-76
Author(s):  
H. Kobayashi
Keyword(s):  
Slip Casting ◽  
Functionally Graded ◽  
Bonding Interface ◽  
Pressureless Sintering ◽  
Sintering Process ◽  
Casting Method ◽  
Slurry Coating ◽  
Epma Analysis

The fabrication of Al2O3-ZrO2~Ni functionally graded pipes has been investigated by slurry coating and pressureless sintering process. Each slurry of Al2O3-ZrO2~Ni mixture and Ni was coated in order on the Al2O3-ZrO2 pipes formed by slip casting method with those slurries. The obtained laminar green pipes were 30 mm in diameter and approximately 90 mm in length. The laminar green pipes were sintered for 2 hours at 1430°C in a vacuum. The structure of pipes fabricated by this method was optically and microscopically examined and the graded distribution was examined by an EPMA analysis of Al and Ni. The pipes with 2 layers of Al2O3-ZrO2 and Ni had crevices in the bonding interface. Some functionally graded pipes with 3 layers were free from cracks and warps without porosity, and each interface had the complete bonding.

scholarly journals Investigation of microstructure and selected properties of Al2O3-Cu and Al2O3-Cu-Mo composites

2020 ◽  
Author(s):  
Justyna Zygmuntowicz ◽  
Joanna Łoś ◽  
Bernard Kurowski ◽  
Paulina Piotrkiewicz ◽  
Waldemar Kaszuwara
Keyword(s):  
Slip Casting ◽  
Sintering Process ◽  
Casting Method ◽  
Metal Composites ◽  
Rheological Study ◽  
X Ray ◽  
Wear Rates ◽  
Flow Limit ◽  
Molybdenum Addition ◽  
The Mean

AbstractThe scope of work included the fabrication of ceramic-metal composites from the Al2O3-Cu and Al2O3-Cu-Mo and examining their microstructure and selected properties. The composites were fabricated by the slip casting method. The rheological behavior, microstructures, X-ray analysis, and mechanical properties were investigated. The rheological study demonstrated that all of the obtained slurries were non-Newtonian shear diluted fluids and stability on time. In both slurries, the flow limit is close to 0 Pa, which is very beneficial when casting the suspensions into molds. The X-ray analysis reveals Al2O3, Cu, and Mo phases in all specimens. No new phases were found in both types of composites after the sintering process. The results provided that the hardness for Al2O3-Cu-Mo composites was equal to 10.06 ± 0.49 GPa, while for Al2O3-Cu, it was equal to 6.81 ± 2.08 GPa. The K1C values measured, with the use of Niihara equation, for composites with and without the addition of Mo were equal to 6.13 ± 0.62 MPa m0.5 and 6.04 ± 0.55 MPa m0.5, respectively. It has been established that the mean specific wear rates of Al2O3-Cu and Al2O3-Cu-Mo samples were 0.35 × 10–5 ± 0.02 mm3 N−1 m−1 and 0.22 × 10–5 ± 0.04 mm3 N−1 m−1, respectively. It was found that molybdenum addition improved wear resistance properties of the composites.

Microstructure of Al2O3-Fe FGM Obtained by Modified Slip-Casting Method

2005 ◽  
Vol 492-493 ◽  
pp. 665-672 ◽  
Author(s):  
A. Ozieblo ◽  
Tomasz Wejrzanowski ◽  
K. Konopka ◽  
Mikolaj Szafran ◽  
Krzysztof Jan Kurzydlowski
Keyword(s):  
Magnetic Field ◽  
Grain Size ◽  
Magnetic Force ◽  
Volume Fraction ◽  
Slip Casting ◽  
Functionally Graded ◽  
Casting Method ◽  
Average Grain Size ◽  
Field Lines ◽  
The Magnetic Field

This paper describes the technology and microstructure of Al2O3-Fe functionally graded composites, FGM, obtained by slip-casting under magnetic field. Alumina a-Al2O3, provided by Alcoa (symbol A16SG), with average grain size of 0.5 µm, and iron powder, (symbol Distaloy AB) from Hoganas, with average grain size of 35 µm, were used to produce a series of specimens which differed in contents of Fe particles in Al2O3. As a source of magnetic force a permanent magnet was used. Preforms were sintered in a vacuum at temp. 1470oC. The microstructures of the specimens were quantitatively described via stereological methods. Sections, parallel to the magnetic field lines were analyzed using special image analysis software. Stereological methods presented in this work have been used to determine gradient in the volume fraction of the Fe particles and variation in their size and dispersion. These parameters are essential for controlling the technological process of interest and to design microstructure for needed properties (fracture toughness).

scholarly journals Investigation on microstructure and selected properties of aluminum oxide–copper–nickel ceramic–metal composites

2021 ◽  
Author(s):  
J. Zygmuntowicz ◽  
J. Kosiorek ◽  
P. Piotrkiewiecz ◽  
B. Zacharko ◽  
M. Wachowski ◽  
...  
Keyword(s):  
Liquid Phase ◽  
Reference Material ◽  
Slip Casting ◽  
Metallic Phase ◽  
Homogeneous Distribution ◽  
Sintering Process ◽  
Casting Method ◽  
Metal Composites ◽  
Microstructure Characteristics ◽  
Nickel Powders

AbstractA new ternary system of ceramic–metal composites has been fabricated from alumina, copper, and nickel powders by the slip casting method. The research aimed to avoid copper leaking during the sintering process of the formation while processing the CuNi phase. Five different compositions were examined, differing in the ratio of nickel to copper. Stable slurries with good casting properties were prepared for all compositions. The final composites after the sintering process were characterized by a homogeneous distribution of the metallic phase, but they differed in the microstructure characteristics. The addition of nickel limits the outflow of the liquid phase (copper) during sintering but does not eliminate it. This resulted in a reduction in the hardness of the samples compared to the reference material.

Fabrication and Properties Analysis of the Thin Walled β''-Alumina Tube

2014 ◽  
Vol 1643 ◽  
Author(s):  
Shimeng Zeng ◽  
Hwan Kim ◽  
Jin-Soo Ahn ◽  
Young-Min Park ◽  
Nigel Mark Sammes
Keyword(s):  
Slip Casting ◽  
Dip Coating ◽  
Alumina Powder ◽  
Dense Layer ◽  
Porous Substrate ◽  
Sintering Process ◽  
Casting Method ◽  
Porous Tube ◽  
Ring Method ◽  
Reaction Processing

ABSTRACTDense thin β/β’’-alumina electrolyte films of less than 50 μm thickness were fabricated using vacuum dip-coating on porous substrate tubes. The porous substrate tubes were fabricated using a slip casting method. Fine Na-β/β’’-alumina powder was obtained via traditional solid state reaction processing. It was found that vacuum dip-coating is an effective method for fabricating thin dense layers coated on the porous tube. The mechanical properties of the porous tube, with and without the dense layer, were tested using a C-ring method. The optimized sintering process was also studied.

scholarly journals Microstructure Characterization of Composite from ZrO2 – Ti System

2017 ◽  
Vol 62 (4) ◽  
pp. 2045-2049 ◽  
Author(s):  
P. Łada ◽  
A. Miazga ◽  
P. Bazarnik ◽  
K. Konopka
Keyword(s):  
Quantitative Analysis ◽  
Dwell Time ◽  
Titanium Powder ◽  
Slip Casting ◽  
Inert Atmosphere ◽  
Sintering Process ◽  
Titanium Particle ◽  
Casting Method ◽  
Composite Samples

AbstractIn this work the microstructure analysis of composite from ZrO2– Ti system were presented. For the preparation of the composite samples nanometric ZrO2powder stabilized by 3 mol% of Y2O3and micrometric titanium powder were used. The composites with 10 vol.% addition of titanium particles were prepared by slip casting method. The sintering process was conducted at 1450°C with 2 hours’ dwell time, in the inert atmosphere of argon. The microstructure observations were carried out with the use of SEM and STEM microscopes. The quantitative analysis and stereological characterization were performed. The SEM and STEM observations allowed characterizing the microstructure of composite samples. Especially, the interface between titanium particles and zirconia matrix was described. The growth of the zirconia grains around the Ti rich areas was observed. The increase of the zirconia grains size results from the reaction on the interface between titanium particle and zirconia matrix during the sintering process.

scholarly journals Zirconia–Alumina Composites Obtained by Centrifugal Slip Casting as Attractive Sustainable Material for Application in Construction

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 250
Author(s):  
Justyna Zygmuntowicz ◽  
Justyna Tomaszewska ◽  
Radosław Żurowski ◽  
Marcin Wachowski ◽  
Paulina Piotrkiewicz ◽  
...  
Keyword(s):  
Slip Casting ◽  
Sintering Process ◽  
Alumina Matrix ◽  
X Ray Diffraction ◽  
Casting Method ◽  
Zro2 Content ◽  
Stereological Analysis ◽  
Alumina Composite ◽  
Alumina Composites ◽  
Sintered Materials

This paper focuses on the possibility of adapting the centrifugal slip casting method to obtain zirconia–alumina composite materials in the form of finished tube-shaped products. These types of products, due to their unique properties, can be utilised, for example, in the transport of aggressive substances, even in extreme temperatures or corrosive conditions. The study reports on the two series of zirconia–alumina composites differing in the content of ZrO2—2.5 and 25 vol%. The fabricated and sintered materials were characterised using scanning electron microscopy (SEM), X-ray diffraction (XRD) and stereological analysis. Moreover, a life cycle assessment (LCA) was provided in accordance with the requirements of the ISO 14044 and EN 15805 standards. The obtained data clearly show that the centrifugal slip casting method allows obtaining samples with high density and extremely uniform distribution of the ZrO2 phase in the alumina matrix. The stereological analysis results proved also that the addition of ZrO2 is effective in reducing the growth of Al2O3 grains during the sintering process. The phase analysis carried out by means of XRD showed that during the sintering process, in the case of composites with a lower ZrO2 content (2.5 vol%), the monoclinic to tetragonal transformation of ZrO2 was total, while for samples containing 25 vol% ZrO2, the monoclinic phase remained in a small amount in the final product.

Combined centrifugal-slip casting method used for preparation the Al2O3-Ni functionally graded composites

2018 ◽  
Vol 141 ◽  
pp. 158-163 ◽  
Author(s):  
Justyna Zygmuntowicz ◽  
Aleksandra Miazga ◽  
Paulina Wiecinska ◽  
Waldemar Kaszuwara ◽  
Katarzyna Konopka ◽  
...  
Keyword(s):  
Slip Casting ◽  
Functionally Graded ◽  
Casting Method ◽  
Functionally Graded Composites

scholarly journals Al2O3/Ni functionally graded materials (FGM) obtained by centrifugal-slip casting method

2017 ◽  
Vol 130 (1) ◽  
pp. 123-130 ◽  
Author(s):  
Justyna Zygmuntowicz ◽  
Paulina Wiecińska ◽  
Aleksandra Miazga ◽  
Katarzyna Konopka ◽  
Waldemar Kaszuwara
Keyword(s):  
Functionally Graded Materials ◽  
Slip Casting ◽  
Functionally Graded ◽  
Casting Method ◽  
Graded Materials

scholarly journals Pressureless Sintering of YIG Ceramics from Coprecipitated Nanopowders

2021 ◽  
Vol 7 (5) ◽  
pp. 56
Author(s):  
Yimin Yang ◽  
Xiaoying Li ◽  
Ziyu Liu ◽  
Dianjun Hu ◽  
Xin Liu ◽  
...  
Keyword(s):  
High Temperature ◽  
Calcination Temperature ◽  
Sintering Temperature ◽  
Raw Materials ◽  
Secondary Phase ◽  
Coprecipitation Method ◽  
Pressureless Sintering ◽  
Densification Behavior ◽  
Sintering Process

Nanoparticles prepared by the coprecipitation method were used as raw materials to fabricate Y3Fe5O12 (YIG) ceramics by air pressureless sintering. The synthesized YIG precursor was calcinated at 900–1100 °C for 4 h in air. The influences of the calcination temperature on the phase and morphology of the nanopowders were investigated in detail. The powders calcined at 1000–1100 °C retained the pure YIG phase. YIG ceramics were fabricated by sintering at 1200–1400 °C for 10 h, and its densification behavior was studied. YIG ceramics prepared by air sintering at 1250 °C from powders calcinated at 1000 °C have the highest in-line transmittance in the range of 1000-3000 nm. When the sintering temperature exceeds 1300 °C, the secondary phase appears in the YIG ceramics, which may be due to the loss of oxygen during the high-temperature sintering process, resulting in the conversion of Fe3+ into Fe2+.

scholarly journals Improvement of mechanical properties of HfB2-based composites by incorporating in situ SiC reinforcement through pressureless sintering

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
S. Ghadami ◽  
E. Taheri-Nassaj ◽  
H. R. Baharvandi ◽  
F. Ghadami
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Relative Density ◽  
Pressureless Sintering ◽  
Sintering Process ◽  
Vacuum Atmosphere ◽  
Sic Reinforcement ◽  
Microstructural Studies ◽  
Composite Samples

AbstractHfB2, Si, and activated carbon powders were selected to fabricate 0–30 vol% SiC reinforced HfB2-based composite. Pressureless sintering process was performed at 2050 °C for 4 h under a vacuum atmosphere. Microstructural studies revealed that in situ SiC reinforcement was formed and distributed in the composite according to the following reaction: Si + C = SiC. A maximum relative density of 98% was measured for the 20 vol% SiC containing HfB2 composite. Mechanical investigations showed that the hardness and the fracture toughness of these composites were increased and reached up to 21.2 GPa for HfB2-30 vol% SiC and 4.9 MPa.m1/2 for HfB2-20 vol% SiC, respectively. Results showed that alpha-SiC reinforcements were created jagged, irregular, and elongated in shape which were in situ formed between HfB2 grains and filled the porosities. Formation of alpha-SiC contributed to improving the relative density and mechanical properties of the composite samples. By increasing SiC content, an enhanced trend of thermal conductivity was observed as well as a reduced trend for electrical conductivity.

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