Pressureless sintering of Al 2 O 3 /Ni nanocomposites produced by heterogeneous precipitation method with varying nickel contents

Processing and mechanical characterization of Al2O3/Ni and Al2O3/C0 composites by pressureless sintering of nanocomposite powders

“…Al 2 O 3 /Co composites are considered an alternative to the Al 2 O 3 /Ni system, due to the superior properties of cobalt, like high melting temperature (1495°C) compared with the nickel systems and good biocompatibility [9][10][11]. The solution chemistry routes, in which metal nitrates are used as metal precursors for the production of ceramic/metal nanocomposites, could be advantageous to provide a fine-scale homogeneity [7,12]. The heterogeneous precipitation method provides not only nanosized metal powders, but also a homogeneous metal particle dispersion [8,12].…”

“…The solution chemistry routes, in which metal nitrates are used as metal precursors for the production of ceramic/metal nanocomposites, could be advantageous to provide a fine-scale homogeneity [7,12]. The heterogeneous precipitation method provides not only nanosized metal powders, but also a homogeneous metal particle dispersion [8,12].…”

“…In this work, Al 2 O 3 /Ni and Al 2 O 3 /Co nanopowder mixtures (with 3 vol.% of metallic phase) were obtained by the heterogeneous precipitation method as it can provide homogeneous metal particle dispersion [8,12]. In ceramic processing, binders are often used to improve the strength of the green compacts and sometimes the relative density [15].…”

“…1.0 M aqueous solution of NH 4 HCO 3 (the precipitation agent) was added dropwise to the prepared slurry under vigorous stirring. The reactions were given by the following equations [8,12,17]:…”

Effects of metal binder on the microstructure and mechanical properties of Al2O3-based micro-nanocomposite ceramic tool material

“…However, compared with WC−Co alloys, WC−Ni alloys demonstrate better corrosion resistance and oxidation resistance [4]. Alumina is the most common matrix, and various metals that have been incorporated into alumina include Ni [5][6][7][8][9] and Mo [10][11]. By controlling the partial pressure of oxygen during the sintering process, the Ni and Al 2 O 3 matrix can exist in the form of Ni spinel (NiAl 2 O 4 ) or Ni and Al 2 O 3 phases.…”