Laser sintering of cold-pressed Cu powder without binder use

Loic Constantin (1, 2) , Lisha Fan (1, 2) , Bruno Mortaigne (3) , Kamran Keramatnejad (1) , Qiming Zou (1) , Clio Azina (2, 1) , Yong Feng Lu (1) , Jean-François Silvain (2, 1)

1 Department of Electrical and Computer Engineering
2 ICMCB - Institut de Chimie de la Matière Condensée de Bordeaux
3 DGA - Direction générale de l'armement [Bagneux]

In this work, laser sintering (LS) of cold-pressed copper (Cu) powder without using a binder was demonstrated. To promote the densification of the final part, the Cu powder was cold pressed beforehand, thereby forming a densely packed powder bed for the LS. The densification and microstructural evolution study show that the cold-pressed powder led to an increase of up to 11% in the relative density and a decrease of 10 times in the surface roughness. The influence of the scan speed on the densification and sintering quality was studied. A relatively slow scan speed, 25 µm/s, allowed sufficient atomic diffusion during the LS process and ultimately produced dense Cu parts without cracks and open pores. The introduction of the cold-pressing step into the LS process is critical for achieving high-density powder metallurgy parts without using binders.

Mots clés: Densification; Laser sintering (LS); Copper powder; Densification; Densification

Domaines: Matériaux

Loic Constantin, Lisha Fan, Bruno Mortaigne, Kamran Keramatnejad, Qiming Zou, et al.. Laser sintering of cold-pressed Cu powder without binder use. Materialia, 2018, 3, pp.178-181. ⟨10.1016/j.mtla.2018.08.021⟩. ⟨hal-01136406⟩