scholarly journals Characterization of Al2O3 Samples and NiAl–Al2O3 Composite Consolidated by Pulse Plasma Sintering

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3398
Author(s):  
Katarzyna Konopka ◽  
Marek Krasnowski ◽  
Justyna Zygmuntowicz ◽  
Konrad Cymerman ◽  
Marcin Wachowski ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Mechanical Alloying ◽  
Ceramic Composites ◽  
Pulse Plasma ◽  
High Plasticity ◽  
Composite Powders ◽  
Microstructural Investigation ◽  
Al2o3 Powder ◽  
Plasma Sintering ◽  
Pulse Plasma Sintering

The paper describes an investigation of Al2O3 samples and NiAl–Al2O3 composites consolidated by pulse plasma sintering (PPS). In the experiment, several methods were used to determine the properties and microstructure of the raw Al2O3 powder, NiAl–Al2O3 powder after mechanical alloying, and samples obtained via the PPS. The microstructural investigation of the alumina and composite properties involves scanning electron microscopy (SEM) analysis and X-ray diffraction (XRD). The relative densities were investigated with helium pycnometer and Archimedes method measurements. Microhardness analysis with fracture toughness (KIC) measures was applied to estimate the mechanical properties of the investigated materials. Using the PPS technique allows the production of bulk Al2O3 samples and intermetallic ceramic composites from the NiAl–Al2O3 system. To produce by PPS method the NiAl–Al2O3 bulk materials initially, the composite powder NiAl–Al2O3 was obtained by mechanical alloying. As initial powders, Ni, Al, and Al2O3 were used. After the PPS process, the final composite materials consist of two phases: Al2O3 located within the NiAl matrix. The intermetallic ceramic composites have relative densities: for composites with 10 wt.% Al2O3 97.9% and samples containing 20 wt.% Al2O3 close to 100%. The hardness of both composites is equal to 5.8 GPa. Moreover, after PPS consolidation, NiAl–Al2O3 composites were characterized by high plasticity. The presented results are promising for the subsequent study of consolidation composite NiAl–Al2O3 powder with various initial contributions of ceramics (Al2O3) and a mixture of intermetallic–ceramic composite powders with the addition of ceramics to fabricate composites with complex microstructures and properties. In composites with complex microstructures that belong to the new class of composites, in particular, the synergistic effect of various mechanisms of improving the fracture toughness will be operated.

scholarly journals Pulse Plasma Sintering of NiAl-Al2O3 Composite Powder Produced by Mechanical Alloying with Contribution of Nanometric Al2O3 Powder

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 407
Author(s):  
Katarzyna Konopka ◽  
Justyna Zygmuntowicz ◽  
Marek Krasnowski ◽  
Konrad Cymerman ◽  
Marcin Wachowski ◽  
...  
Keyword(s):  
Mechanical Alloying ◽  
Composite Powder ◽  
Pulse Plasma ◽  
Alumina Powder ◽  
Composite Powders ◽  
Plasma Sintering ◽  
Al2o3 Composite ◽  
Ultrafine Grained ◽  
Pulse Plasma Sintering ◽  
Nial Matrix

NiAl-Al2O3 composites, fabricated from the prepared composite powders by mechanical alloying and then consolidated by pulse plasma sintering, were presented. The use of nanometric alumina powder for reinforcement of a synthetized intermetallic matrix was the innovative concept of this work. Moreover, this is the first reported attempt to use the Pulse Plasma Sintering (PPS) method to consolidate composite powder with the contribution of nanometric alumina powder. The composite powders consisting of the intermetallic phase NiAl and Al2O3 were prepared by mechanical alloying from powder mixtures containing Ni-50at.%Al with the contribution of 10 wt.% or 20 wt.% nanometric aluminum oxide. A nanocrystalline NiAl matrix was formed, with uniformly distributed Al2O3 inclusions as reinforcement. The PPS method successfully consolidated NiAl-Al2O3 composite powders with limited grain growth in the NiAl matrix. The appropriate sintering temperature for composite powder was selected based on analysis of the grain growth and hardness of Al2O3 subjected to PPS consolidation at various temperatures. As a result of these tests, sintering of the NiAl-Al2O3 powders was carried out at temperatures of 1200 °C, 1300 °C, and 1400 °C. The microstructure and properties of the initial powders, composite powders, and consolidated bulk composite materials were characterized by SEM, EDS, XRD, density, and hardness measurements. The hardness of the ultrafine-grained NiAl-Al2O3 composites obtained via PPS depends on the Al2O3 content in the composite, as well as the sintering temperature applied. The highest values of the hardness of the composites were obtained after sintering at the lowest temperature (1200 °C), reaching 7.2 ± 0.29 GPa and 8.4 ± 0.07 GPa for 10 wt.% Al2O3 and 20 wt.% Al2O3, respectively, and exceeding the hardness values reported in the literature. From a technological point of view, the possibility to use sintering temperatures as low as 1200 °C is crucial for the production of fully dense, ultrafine-grained composites with high hardness.

Nanocrystalline Cemented Carbides Sintered by the Pulse Plasma Method

2006 ◽  
Vol 114 ◽  
pp. 245-250
Author(s):  
Andrzej Michalski ◽  
D. Siemiaszko ◽  
Jakub Jaroszewicz ◽  
Marcin Rosiński ◽  
M. Psoda
Keyword(s):  
Fracture Toughness ◽  
Relative Density ◽  
Crystallite Size ◽  
Sintering Temperature ◽  
Pulse Plasma ◽  
Cemented Carbides ◽  
Plasma Method ◽  
Plasma Sintering ◽  
Pulse Plasma Sintering

Nanocrystalline WC-12wt.%Co was consolidated by Pulse Plasma Sintering (PPS) at various temperatures between 900 and 1200oC for 6 minutes under a pressure of 60MPa. Cemented carbides sintered at 1100oC have a relative density of 99%, a hardness of 2248HV30, the fracture toughness, KIC=12.5 MPa*m1/2, and have a structure containing 50nm WC crystallites. Increasing the sintering temperature to 1200oC causes an increase in the size of the WC crystallite size to about 110 nm, reduces the hardness to 2198HV30, and decreases the KIC to 9.7 MPa*m1/2.

Microstructure and thermoelectric properties of p and n type doped β-FeSi2 fabricated by mechanical alloying and pulse plasma sintering

2019 ◽  
Vol 8 ◽  
pp. 531-539 ◽  
Author(s):  
Franciszek Dąbrowski ◽  
Łukasz Ciupiński ◽  
Joanna Zdunek ◽  
Jakub Kruszewski ◽  
Rafał Zybała ◽  
...  
Keyword(s):  
Mechanical Alloying ◽  
Thermoelectric Properties ◽  
Pulse Plasma ◽  
Plasma Sintering ◽  
Pulse Plasma Sintering

W/Cu composites produced by pulse plasma sintering technique (PPS)

2007 ◽  
Vol 82 (15-24) ◽  
pp. 2621-2626 ◽  
Author(s):  
M. Rosinski ◽  
E. Fortuna ◽  
A. Michalski ◽  
Z. Pakiela ◽  
K.J. Kurzydlowski
Keyword(s):  
Pulse Plasma ◽  
Plasma Sintering ◽  
Pulse Plasma Sintering

scholarly journals Formation and Properties of the Ta-Y2O3, Ta-ZrO2, and Ta-TaC Nanocomposites

2018 ◽  
Vol 2018 ◽  
pp. 1-12
Author(s):  
J. Jakubowicz ◽  
M. Sopata ◽  
G. Adamek ◽  
P. Siwak ◽  
T. Kachlicki
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Mechanical Alloying ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Ceramic Composites ◽  
Ceramic Phase ◽  
Plasma Sintering ◽  
Average Grain Size ◽  
Bulk Nanocrystalline

The nanocrystalline tantalum-ceramic composites were made using mechanical alloying followed by pulse plasma sintering (PPS). The tantalum acts as a matrix, to which the ceramic reinforced phase in the concentration of 5, 10, 20, and 40 wt.% was introduced. Oxides (Y2O3 and ZrO2) and carbides (TaC) were used as the ceramic phase. The mechanical alloying results in the formation of nanocrystalline grains. The subsequent hot pressing in the mode of PPS results in the consolidation of powders and formation of bulk nanocomposites. All the bulk composites have the average grain size from 40 nm to 100 nm, whereas, for comparison, the bulk nanocrystalline pure tantalum has the average grain size of approximately 170 nm. The ceramic phase refines the grain size in the Ta nanocomposites. The mechanical properties were studied using the nanoindentation tests. The nanocomposites exhibit uniform load-displacement curves indicating good integrity and homogeneity of the samples. Out of the investigated components, the Ta-10 wt.% TaC one has the highest hardness and a very high Young’s modulus (1398 HV and 336 GPa, resp.). For the Ta-oxide composites, Ta-20 wt.% Y2O3 has the highest mechanical properties (1165 HV hardness and 231 GPa Young’s modulus).

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