Effect of Ni content and Al^sub 2^O^sub 3^ particle size on the thermal and mechanical properties of Al^sub 2^O^sub 3^/Ni composites prepared by spark plasma sintering

Alumina-nickel composites were prepared by carrying out spark plasma sintering (SPS) of nano-sized and micro-sized Al2O3 particles with 15–45 wt% Ni powders. The powder materials were sintered at a temperature of 1400 °C under a constant uniaxial pressure of 50 MPa. FESEM micrographs of the products...

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Bibliographic Details
Published in:International journal of refractory metals & hard materials 2018-11, Vol.76, p.25
Main Authors: Irshad, Hafiz Muzammil, Hakeem, Abbas Saeed, Ahmed, Bilal Anjum, Ali, Sharafat, Ali, Sadaqat, Ali, Sameer, Ehsan, Muhammad Ali, Laoui, Tahar
Format: Article
Language:English
Subjects:
Aluminum alloys
Aluminum oxide
Composite materials
Fracture toughness
Heat conductivity
Mechanical properties
Microstructure
Nickel
Particle size
Photomicrographs
Spark plasma sintering
Thermal conductivity
Thermal cycling
Thermodynamic properties
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Summary:Alumina-nickel composites were prepared by carrying out spark plasma sintering (SPS) of nano-sized and micro-sized Al2O3 particles with 15–45 wt% Ni powders. The powder materials were sintered at a temperature of 1400 °C under a constant uniaxial pressure of 50 MPa. FESEM micrographs of the products showed uniformly dispersed nickel inclusions in both matrices at intergranular positions. Presence of Al2O3 as the major phase along with Ni as the minor phase was confirmed using XRD analysis. Thermal and mechanical properties of the nano- and micro-sized Al2O3/Ni composites were investigated. The thermal conductivity of nano-sized alumina composites was seen to increase with the increase in nickel content, however, an opposite trend was observed for micro-sized alumina-based composites. Moreover, thermal conductivities of all the composites decreased with increase in temperature. The composites also showed high hardness and fracture toughness values of up to 19.6 GPa and 4.71 MPa ∗ m1/2, respectively, and relative density values, between 79 and 99%, that decreased with increasing Ni content. Furthermore, the nano-sized Al2O3/Ni composites showed thermal and mechanical properties superior to those of the micro-sized Al2O3/Ni composites.
ISSN:0263-4368