Accession Number:

ADA334772

Title:

A Study in the Interfacial Stability of Ti/Al2O3, Ti3Al/Al2O3 and TiAl/Al2O3 Composite Materials

Descriptive Note:

Final rept.

Corporate Author:

AIR FORCE RESEARCH LAB BOLLING AFB DC

Personal Author(s):

• DeKock, Joel A.

Report Date:

1995-01-01

Pagination or Media Count:

172.0

Abstract:

This thesis is a study of the interfacial stability of the Ti-Base metal matrix composites TiAl2O3, Ti3AlAl2O3 and TiAlAl2O3. Interfacial stability is discussed in view of the importance of thermodynamics and kinetics as the primary considerations which govern the type of stability observed. From a thermodynamics approach, the application of phase equilibrium diagrams is essential in the design of composite systems. A classification system, with reference to phase equilibrium, is used to describe the type of interfacial stability observed for the composites studied. In addition, electron-probe microanalysis, atom-probe field ion microscopy and X-ray diffraction results are used to establish Ti-Al-O phase relations for the temperature range 900-to-1250 deg C. The kinetics of interfacial stability is discussed with particular attention given to the kinetic considerations diffusion path, phase formation sequence, steady-state layer growth and interface morphology. Kinetic results in the form of parabolic growth constants and calculated interdiffusion coefficients are presented.

Descriptors:

• *STABILITY
• *INTERFACES
• *ALUMINUM OXIDES
• *TITANIUM ALUMINIDE
• *TITANIUM COMPOUNDS
• STEADY STATE
• LAYERS
• THERMODYNAMICS
• COMPOSITE MATERIALS
• GROWTH(GENERAL)
• MORPHOLOGY
• X RAY DIFFRACTION
• THESES
• METAL MATRIX COMPOSITES
• CRACK PROPAGATION
• CLASSIFICATION
• DIFFUSION
• KINETICS
• PHASE DIAGRAMS
• MICROANALYSIS
• ELECTRON PROBES

Subject Categories:

• Laminates and Composite Materials
• Properties of Metals and Alloys

Distribution Statement:

APPROVED FOR PUBLIC RELEASE