Microstructure evolution and densification during spark plasma sintering of nanocrystalline W-5wt.%Ta alloy

TL;DR

This study investigates how tantalum affects densification and microstructure evolution in nanocrystalline tungsten during spark plasma sintering, revealing microstructural stabilization and grain size outcomes.

Contribution

It provides new insights into the role of tantalum in microstructure stabilization during spark plasma sintering of nanocrystalline tungsten.

Findings

Tantalum stabilizes microstructure during sintering.

Average grain size achieved was 1.73 microns.

Tantalum influences densification behavior.

Abstract

The present work reports the effect of Ta on densification and microstructure evolution during non-isothermal and spark plasma sintering of nanocrystalline W. Nanocrystalline W-5wt.%Ta alloy powder was synthesized using mechanical alloying. The nanocrystalline powder was characterized thoroughly using X-ray diffraction line profile analysis. Furthermore, the shrinkage behavior of nanocrystalline powder was investigated during non-isothermal sintering using dilatometry. Subsequently, the alloy powder was consolidated using spark plasma sintering up to 1600 {\deg}C. The role of Ta on stabilizing the microstructure during spark plasma sintering of nanocrystalline W was investigated in detail using electron backscatter diffraction. The average grain size of spark plasma sintered W-5wt.%Ta alloy was observed as 1.73 micron.