Reactive sintering of porous tungsten: A cost effective sustainable technique for the manufacturing of high current density cathodes to be used in flashlamps

Abstract

Tungsten ( T m = 3410 ± 20 °C) is traditionally sintered at temperatures in excess of 2000 °C under hydrogen atmosphere using high temperature furnaces. The process is extremely expensive and it is difficult to gain a control over the microstructure. One of the important applications of this metal makes use of its porous form as a high current density cathode employed in flashlamps (high power laser lamps). For an improved performance and longer lifetime, a controlled porosity is essential. This study briefly highlights the advantages of an alternative sintering technique based on the concept of reactive sintering previously introduced. This novel process makes use of a small amount of Al addition. Consequently, the sintering temperature is reduced considerably ( T s ≤ 1200 °C) and a more homogeneous porous tungsten is obtained irrespective of the compaction method employed.