Formation of zirconium and nickel oxide nanoparticles via oxidation of quenched melted Ni–Zr alloys

Influence of Spark plasma sintering on the tetragonal phase of ZrO 2 ‐NiO nanosized powders synthesised via oxidation of quenched melted Ni 40 ‐Zr 60 alloy

“…2 [15]. As discussed in our previous work [15], the bright zone is composed of agglomerates of well distinct NiO nanoparticles, whose diameter can be estimated to be in the range 10–50 nm, whereas the dark background is constituted of agglomerates of smaller ZrO 2 particles. The formation of such agglomerates stems to segregations effects due to the preferential oxidation of zirconium.…”

“…SEM characterisations: The SEM-EDS characterisation of agglomerates of ZrO 2 -NiO, obtained after oxidation (in oxygen at 800°C during 2 h) of quenched melted Ni 60 -Zr 40 alloy (in liquid nitrogen) is shown in Fig. 2 [15]. As discussed in our previous work [15], the bright zone is composed of agglomerates of well distinct NiO nanoparticles, whose diameter can be estimated to be in the range 10-50 nm, whereas the dark background is constituted of agglomerates of smaller ZrO 2 particles.…”

“… SEM‐EDS characterisation of agglomerates of ZrO 2 ‐NiO that are obtained after oxidation (in oxygen at 800°C during 2 h) of quenched melted Ni 60 ‐Zr 40 alloy (in liquid nitrogen) from (Saidi et al [15]) a Nickel oxide zone and b Zirconium oxide zone…”

“…In a previous work, a method for synthesising homogeneous mixture of ZrO 2 and NiO nano-sized particles, by the oxidation of quenched melted Zr-Ni alloy (in liquid nitrogen), has been described [15]. The aim of the present work is to investigate the sintering of this homogeneous composite by using the SPS technique.…”

“…Materials processing and characterisation techniques 2.1. Powder synthesis method: The composite ZrO 2 -NiO was processed in two steps: (i) quenching melted Ni 40 -Zr 60 alloy in liquid nitrogen and (ii) oxidation in air at 850°C during 12 h. This method, which has been introduced in a previous work [15], provides a mixture of agglomerates, consisting of NiO and ZrO 2 nano-sized particles. A good homogeneity of this mixture is expected because of the first step of melting.…”