The Investigation and Production of Titanium-Tantalum Junctions Diffusion Bonded at High Temperature (855C to 920C): the Influence of Temperature, Time Pressure and Roughness on the Mechanical Properties, and the Optimisation of the Bonded Conditions

Abstract

This investigation shows that, despite a clear Kirkendall effect, it is possible within the technical constraints to find a combination of the four main operating parameters (temperature, time, pressure and roughness) allowing the successful diffusion bonding of titanium and tantalum (with fracture of the tensile test specimens occurring in the tantalum at 360 MPa). The optimum temperature range at low pressure (2 to 5 MPa) lies in the alpha phase of titanium at 875 to 885 deg C. The pressure, which plays a decisive role in the resorption kinetics of residual defects, must be greater than 2 MPa to ensure the production of strong and ductile junctions in a reasonable time. The application of a temporary overpressure during heating offers many advantages, such as limited deformation of test pieces, saving of time, the production of better quality junctions, and even the bonding of surfaces with significant roughness. (TTL)

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Document Details

Document Type
Technical Report
Publication Date
Jan 01, 1990
Accession Number
ADA228217

Entities

People

  • B. Hocheid
  • M. Hourcade
  • M. Veyrac
  • S. Pineau

Organizations

  • Royal Aircraft Establishment

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Assembly
  • Diffusion Bonding
  • Electron Microscopes
  • High Pressure
  • Kirkendall Effect
  • Materials
  • Measurement
  • Mechanical Properties
  • Metals
  • Microscopes
  • Plastic Explosives
  • Plastic Flow
  • Production
  • Roughness
  • Scanning Electron Microscopes
  • Surface Properties
  • Tensile Strength

Fields of Study

  • Materials science

Readers

  • Materials Science and Engineering.
  • Powder metallurgy of Titanium alloys.
  • Surface Coatings Technology.