Sintering behavior and mechanism of tungsten powders prepared by solution combustion synthesis combined with hydrogen reduction

Tianhao Zhang,Wen Yang,Xiaodong Zhang,Pengqi Chen

doi:10.1088/2053-1591/ac19e8

Abstract

Nanosized tungsten powders were fabricated by solution combustion synthesis combined with hydrogen reduction. The powder had a size of 20 nm but possessed a large numbers of lattice defects. The fracture surface images at different temperatures show that the as-synthesized tungsten powder could be sintered via a pressureless process to relative density up to 95.78% at 1773 K. Kinetic analysis suggests that grain-boundary diffusion is one of the primary mechanisms of mass transport during the intermediate stage of sintering. The sintering properties are attributed to the ultrafine grain and the high sintering activation caused by the effect of the solution combustion synthesis method. It reveals in detail that the as-synthesized tungsten powder has a lower sintering activation energy compared to commercial nanosized tungsten powder, with a measured hardness of 633 HV.

Highlights

August 2021The fracture surface images at different temperatures show that the as-synthesized tungsten powder could be sintered via a pressureless process to relative density up to 95.78% at 1773 K
Tungsten is a strategic material that has received much attention due to its excellent properties
The fracture surface images at different temperatures show that the as-synthesized tungsten powder could be sintered via a pressureless process to relative density up to 95.78% at 1773 K

Summary

August 2021

The fracture surface images at different temperatures show that the as-synthesized tungsten powder could be sintered via a pressureless process to relative density up to 95.78% at 1773 K. Kinetic analysis suggests that grain-boundary diffusion is one of the primary mechanisms of mass transport during the intermediate stage of sintering. The sintering properties are attributed to the ultrafine grain and the high sintering activation caused by the effect of the solution combustion synthesis method. It reveals in detail that the as-synthesized tungsten powder has a lower sintering activation energy compared to commercial nanosized tungsten powder, with a measured hardness of 633 HV

Introduction

Experimental procedures

Results and discussions

Conclusions