Deformation of Field Ion Microscopy Tips by Mechanical Contact.

Abstract

Tungsten and iridium field ion microscope (FIM) tips served as asperities which were subjected to measurable compressive loads by mechanically contacting them in air to tungsten and platinum plates. FIM tips contacted with tungsten displayed dented regions of irregular shape, where FIM tips contacted to platinum had well designed, nearly circular contact regions. Average contact pressures were calculated. Mechanically induced twinning on the (111) planes of (001) oriented iridium tips was observed to occur for iridium-tungsten and iridium-platinum contacts. This can be explained by an imperfect slip of each layer of the (111) plane into a <112> direction. The critical shear stress necessary for twinning was also estimated. (Author)

Document Details

Document Type
Technical Report
Publication Date
Jan 15, 1971
Accession Number
AD0739709

Entities

People

  • Robert J. Walko

Organizations

  • Pennsylvania State University

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Elements
  • Field Ion Microscopy
  • Metals
  • Microscopes
  • Microscopy
  • Optical Analysis
  • Platinum
  • Shape
  • Shear Stresses
  • Stresses
  • Transition Metals
  • Tungsten

Readers

  • Electrochemical Engineering/ Fuel Cell Technologies
  • Materials Science (Mechanical Engineering).
  • Tribology (the study of the boundary interaction between sliding surfaces, lubrication, wear and friction).