Stability, deoxidation, and sintering characteristics of activated Mo–10%Nb solid-solution powders prepared by mechanical alloying

Abstract

Refractory Mo–10%Nb sputtering targets play a key role in the electronic integrated circuit and flat panel display industries. However, the fabrication of high-performance Mo–10%Nb sputtering targets is a challenging task. In order to improve the sintering densification and homogeneity of Mo–10%Nb targets, activated Mo–10%Nb solid-solution powders were prepared and characterised in our previous study. In this research, the structural stability, deoxidation characteristics, and sintering behaviours of activated Mo–10%Nb solid-solution powders were investigated. The results revealed that the crystal structure and composition of the activated powders had good stability when stored in vacuum at room temperature for 30 days. Further, the oxygen content of the activated powders was mainly concentrated at the surface, as confirmed by electron probe microanalysis and X-ray photoelectron spectrometry. The oxygen content could be significantly decreased from ∼6000 to ∼3000 ppm by a deoxidation process using Mg as the reductant. Finally, the density of the sintered billet increased from 86.19 to 91.36% upon using the Mo–10%Nb solid-solution powder, and the homogeneity of the composition and microstructure was greatly improved. Moreover, the average grain size decreased from 20.89 to 6.69 μm. This research suggests that activated Mo–10%Nb solid-solution powders can effectively improve the quality of sintered Mo–10%Nb targets.

Keywords

• Activated Mo–10%Nb powder
• Structural stability
• Deoxidation
• Magnesium thermal reduction
• Densification by sintering