Micromechanisms of Monotonic and Cyclic Subcritical Crack Growth in Advanced High Melting Point Low-Ductility Intermetallics

Abstract

The next generation of high-performance engines will require stiffer materials, operating at higher stress levels and capable of with-standing significantly higher temperatures up to 1650 deg C and above. Prime candidates for such applications include ordered intermetallics, ceramics, and composites based on metal, intermetallic and ceramic or carbon matrices. However, these materials are currently of limited use due to their low ductility and toughness properties; moreover, an understanding of their fatigue resistance is still essentially lacking. Accordingly, the present research was aimed at examining one class of these materials, namely ductile-phase toughened intermetallic alloys, with respect to the critical factors influencing crack-propagation resistance under monotonic and cyclic loading. The model systems studied included TiNb- and Nb-reinforced gamma-TiAl, Nb-reinforced Nb3Al, and Nb- reinforced MoSi2....Intermetallic composites, Fatigue crack propagation, Fracture toughness

Open PDF

Document Details

Document Type
Technical Report
Publication Date
May 01, 1993
Accession Number
ADA267764

Entities

People

  • K. T. Venkateswara Rao
  • L. Murugesh
  • Robert O. Ritchie

Organizations

  • University of California, Berkeley

Tags

Communities of Interest

  • Air Platforms
  • C4I
  • Energy and Power Technologies
  • Space

DTIC Thesaurus Topics

  • Air Force
  • Ceramic Materials
  • Composite Materials
  • Crack Propagation
  • Crystal Structure
  • Electron Microscopes
  • Materials
  • Materials Laboratories
  • Materials Science
  • Mechanical Properties
  • Mechanical Working
  • Mechanics
  • Modulus Of Elasticity
  • Phase Transformations
  • Solid Solutions
  • Toughness
  • Transition Temperature

Fields of Study

  • Materials science

Readers

  • Materials Science (Mechanical Engineering).
  • Powder metallurgy of Titanium alloys.
  • Reinforced Composite Materials