Electroconductive Alumina–TiC–Ni nanocomposites obtained by Spark Plasma Sintering

Abstract

In the present work, the processing and characterization of electroconductive Alumina-TiC-Ni nanocomposites obtained by Spark Plasma Sintering (SPS) are described. These nanocomposites are singular due to the excellent mechanical properties they present (particular regarding Vickers hardness, 25.6 AE 0.7 GPa), as well as their extremely good wear behaviour, studied under ''ball-on-disk'' dry sliding conditions. The wear rate obtained was 25 times (almost 1.5 orders of magnitude) smaller than the value obtained for a monolithic alumina sintered under the same conditions. Flexural strength had been improved up to 75% with respect to the monolithic alumina processed under the same conditions. As these nanocomposites can be machined by electroerosion (EDM), they can adopt any shape for devices requiring a good mechanical performance and low wear rates.

Wear behavior of graphene/alumina composite

“…In order to estimate correctly the volume losses, the track profiles were analyzed with a surface profilometer (Talysurf CLI 500, Taylor Hobson, Leicester, UK) that maps the surface by putting a stylus in mechanical contact with the sample [18][19][20]. Both, the microstructure of the sintered specimens surfaces (polished down to 1 μm) and the wear scars were studied by scanning electron microscopy (SEM, Hitachi, model S3000 N).…”

Shear‐induced brittle failure of titanium carbide from quantum mechanics simulations

“…In the unit cell, each C atom is octahedrally coordinated with 8 Ti atoms (CTi 8 ) and vice versa . For decades, many attempts have been made to improve the toughness of TiC while maintaining its high hardness, both in theory and experiments . One method is to add metals and metal oxides to improve the toughness of TiC .…”

Mechanical and tribological properties of ceramic/metal composites: A review of phenomena spanning from the nanometer to the micrometer length scale

“…In general terms, the final roughness of the workpiece after cutting was less than 1 m (for more details see Ref. 41). Zirconia-TiC-Ni nanocomposites were also successfully machined by this technique.…”

“…The applied load (F N ) was 10 N, corresponding to initial Hertzian contact pressures of 2.5 GPa, and tests lasted 60 h, which corresponded to a sliding distance (S) of ∼3255 m. Further explanations concerning wear test and sample preparation and evaluation can be found in Ref. 41.…”

“…41. TiC content was selected to be 25 vol.% (with respect to the final composition) for being a concentration over the percolation threshold (f c ∼ 16 vol.%).…”