Accession Number:

ADA242236

Title:

Strengthening of NiAl Matrix Composites

Descriptive Note:

Annual rept. Oct 90-Sep 91,

Corporate Author:

MARYLAND UNIV COLLEGE PARK METALLURGICAL MATERIALS LAB

Personal Author(s):

Report Date:

1991-10-01

Pagination or Media Count:

75.0

Abstract:

Deformation of titanium boridenickel aluminum composites at high temperatures exhibit low temperature deformation characteristics, and grain size refinement in these composites could account for the strengthening of the composites. Interfaces of TiB2-NiA1 and alpha--aluminum oxides--NiAR in TiB2 NiA1 composites have been investigated by analytical electron microscopy. Although no consistent crystallographic orientation relationships have been found between NiA1 and TiB2 or A12O3, semicoherent interfaces between alpha- A12O3 and NiA1 have been observed in areas where the low indexed crystallographic planes of alpha-A12O3 aligned with that of NiA1. No semicoherent interfaces between NiA1 and TiB2 have been observed. Silicon segregation was consistently detected by at the TiB2NiA1 interface region. Segregation has not been detected in the alpha-A12O3-NiA1 interface region. The segregation layer observed at the TiB2-NiA1 interface is too thin to absorb any of the thermal residual stress.

Subject Categories:

  • Inorganic Chemistry
  • Laminates and Composite Materials
  • Metallurgy and Metallography

Distribution Statement:

APPROVED FOR PUBLIC RELEASE