The effects of depth of cut and pre-cooling on surface porosity in cryogenic machining of porous tungsten

Research output: Contribution to journalConference articlepeer-review

17 Scopus citations


Cryogenic machining of porous tungsten is an effective method to achieve as-machined porous surfaces. Dispenser cathodes, which are high performance electron emitting devices, rely on the (surface) porosity of porous tungsten for their functionality. Conventional (dry, flood, MQL) machining results in unwanted smearing of surface pores and requires the use of a plastic infiltrant to stabilize pores during machining. Previous studies have shown the ability of PCD tools to achieve controlled micro-fracture which occurs only at low cutting speeds (vc~10-20 m/min) along with cryogenic cooling. This study investigates the influence of cryogenic pre-cooling time and depth of cut on the attainable surface morphology of porous tungsten. Negative rake cermet tool inserts were used to demonstrate the ability of non-diamond tools to achieve similar results. Three cryogenic pre-cooling times (60, 120 and 180s) are compared to establish their relative effectiveness in enabling the infiltrant-free cryogenic machining of porous tungsten with the objective of achieving maximum surface porosity. It is found that increased pre-cooling time increases the asmachined surface porosity and significantly alters the deformation mechanism during machining. Lastly, a qualitative relationship between the chips generated during the cryogenic machining and as-machined surface porosity is laid out.

Original languageEnglish
Pages (from-to)357-362
Number of pages6
JournalProcedia CIRP
StatePublished - 2013
Event14th CIRP Conference on Modeling of Machining Operations, CIRP CMMO 2013 - Turin, Italy
Duration: Jun 13 2013Jun 14 2013


  • Cryogenic machining
  • Porous tungsten
  • Surface integrity

ASJC Scopus subject areas

  • Control and Systems Engineering
  • Industrial and Manufacturing Engineering


Dive into the research topics of 'The effects of depth of cut and pre-cooling on surface porosity in cryogenic machining of porous tungsten'. Together they form a unique fingerprint.

Cite this