Authors:
Frédéric Bernard (ICB – UMR 6303 CNRS | UBFC, France),
Arnaud Bolsonella (SINTERMAT, France),
Mathias Moser (ICB – UMR 6303 CNRS | UBFC, France),
Hervé Couque (Nexter Munitions, France)
Abstract:
The work engaged for many years between the ICB laboratory and the Nexter Munitions company has clearly shown the interest of combining a high-energy mechanical milling of the metallic powders followed by a SPS sintering. Indeed, commercial powders are mechanically activated (i.e. successive actions of fracture | cold welding of the powder particles) by the use of high-energy planetary ball mill, which leads (i) to increase the agglomerate sizes, (ii) to reduce the crystallite sizes and (iii) to induce structural defects. Thus, these so-called mechanically activated agglomerates allow a densification at a lower temperature while avoiding the formation of undesirable phases and limiting the grain growth. The second interest of mechanical milling is to stabilize sometimes out-of-equilibrium phases. Several examples (nickel, maraging steels, …) will exhibit the existence of a relationship between the powder microstructure and sintered microstructure and consequently on the tensile properties.
DOI:
https://doi.org/10.59499/WP225372097