Effect of Ni content and Al2O3 particle size on the thermal and mechanical properties of Al2O3/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 Al2O3particles with 15–45 wt% Ni powders. The powder materials were sintered at a temperature of1400 °C under a constant uniaxial pressure of 50 MPa. FESEM micrographs of the products showed uniformlydispersed nickel inclusions in both matrices at intergranular positions. Presence of Al2O3as the major phasealong with Ni as the minor phase was confirmed using XRD analysis. Thermal and mechanical properties of thenano- and micro-sized Al2O3/Ni composites were investigated. The thermal conductivity of nano-sized aluminacomposites was seen to increase with the increase in nickel content, however, an opposite trend was observed formicro-sized alumina-based composites. Moreover, thermal conductivities of all the composites decreased withincrease in temperature. The composites also showed high hardness and fracture toughness values of up to19.6 GPa and 4.71 MPa ∗ m1/2, respectively, and relative density values, between 79 and 99%, that decreasedwith increasing Ni content. Furthermore, the nano-sized Al2O3/Ni composites showed thermal and mechanicalproperties superior to those of the micro-sized Al2O3/Ni composite.

Subject headings

TEKNIK OCH TEKNOLOGIER  -- Materialteknik -- Keramteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Materials Engineering -- Ceramics (hsv//eng)

Keyword

Alumina Nickel Composite Structural properties Thermo-mechanical properties Spark plasma sintering

Glasteknologi

Glass Technology

Publication and Content Type

ref (subject category)

art (subject category)