Consolidation of Molybdenum nanopowders by spark plasma sintering: Densification mechanism and first mirror application

Geuntak Lee (1) , Charles Manière (1) , Joanna Mckittrick (2) , Russell Doerner (3) , Daisuke Nishijima (3) , Anthony Gattuso (4) , Tyler Abrams (4) , Dan Thomas (4) , Christina Back (4) , Eugene A. Olevsky (1)

1 SDSU - San Diego State University
2 MAE - UC San Diego - Department of Mechanical and Aerospace Engineering [Univ California San Diego]
3 Center for Energy Research [La Jolla]
4 General Atomics [San Diego]

Mo nanopowders are synthesized by ball milling and the following hydrogen reduction of MoO3 powders. The densification mechanism of Mo nanopowders during spark plasma sintering (SPS) is analyzed by the combination of the regression of the experimental data on regular SPS and on the SPS multistep pressure dilatometry based on the continuum theory of the sintering. The Mo mirror with 400 nm average grain size and 93% relative density is fabricated by the SPS. The performance of the mirrors made from a single crystal Mo and from the hydrogen-reduced sintered Mo nanopowder is discussed. The microstructure and optical properties of the mirrors are characterized before and after plasma exposure, and no substantial degradation of the reflectivity was observed.

Domaines: Matériaux; Mécanique des matériaux [physics.class-ph]; Génie des procédés

Geuntak Lee, Charles Manière, Joanna Mckittrick, Russell Doerner, Daisuke Nishijima, et al.. Consolidation of Molybdenum nanopowders by spark plasma sintering: Densification mechanism and first mirror application. Journal of Nuclear Materials, 2019, 516, pp.354-359. ⟨10.1016/j.jnucmat.2019.01.028⟩. ⟨hal-02616801⟩