Synthesis and characterisation of Al₂O₃/Ni-type composites obtained by spark plasma sintering

Abstract

This paper presents the influence of sintering on the structure, morphology and compressing strength of alumina/nickel composite compacts obtained by spark plasma sintering (SPS). Al 2 O 3 /Ni composites were prepared by SPS in argon atmosphere at temperatures in the range of 1000-1200 -C with a holding time of 2, 5 and 10 minutes. The heating rate was 200 C min −1 . These composites have been characterised by X-ray diffraction, SEM and EDX. The relative density and compressive strength of the as-obtained compacts were determined. The results showed that the alumina particles are uniformly dispersed in a quasi-continuous Ni network, and there was no sign of phase changes during sintering. The maximum strength of the alumina/nickel composite with a content of 75 vol. − Al 2 O 3 and 25 vol. − Ni was about 240 MPa for the samples sintered at 1200 C for 10 minutes.

Influence of Alumina Nanofibers Sintered by the Spark Plasma Method on Nickel Mechanical Properties

“…In the literature, [41] said that in order to form more than 0.5 wt.% NiO (in the Ni-Al 2 O 3 system), it is necessary to make the process in the air (except at a high temperature of up to 800 • C with a holding time over 12 min). According to work [42] about the SPS sintering influence of nickel with a high alumina content, at a sintering temperature of 1200 • C for 10 min there was no noticeable nickel oxide formation. It should also be noted that the probability of the appearance of metal-to-metal contacts during spark plasma sintering at a pressure of more than 10 MPa makes it possible to destroy the film by analogy with aluminum [43,44].…”

Dielectric Studies of Bi2MoO6/Graphene Oxide and La-Doped Bi2MoO6/Graphene Oxide Nanocomposites

“…Values of tan δ were 0.75, 1.82, and 1.79 for 2, 3, and 4% weight of Bi2MoO6, respectively, and the values of tan δ of La-Bi2MoO6/GO were 0.65, 0.71, and 0.88, respectively. The increase in tan δ with the increase in Bi2MoO6 content in GO is attributed to the conductive nature of Bi2MoO6 [42], while the increase in tan δ with increase in Bi2MoO6/GO is attributed to the conductive network formation, dipole polarization, and interfacial polarization [43], as there exists a relation between electrical conduction ɛ' and ɛ'' [44,45].…”

Superalloy/Al2O3 type composite compacts obtained by spark plasma sintering from mechanically alloyed powders

“…This process has been widely used to obtain magnetic materials, ODS alloys and composite Fe, Ni and Co superalloy reinforced with ceramic particles [16,27,28]. In our previous study, we obtained the Al 2 O 3 /Ni composite, in which the alumina particles are uniformly dispersed in a quasi-continuously Ni network [29].…”