Accession Number:

ADA256970

Title:

Strengthening of NiAl Matrix Composites

Descriptive Note:

Annual rept. Oct 1991-Sep 1992

Corporate Author:

MARYLAND UNIV COLLEGE PARK METALLURGICAL MATERIALS LAB

Personal Author(s):

Report Date:

1992-10-01

Pagination or Media Count:

58.0

Abstract:

An investigation was undertaken to determine if by cryomilling NiAl and TiB2 powders ultra fine subgrain or grain size material could be obtain. If this ultra fine grain size composite were produced then it was assumed there should be a significant increase in the strength. Cryomilling did decrease the grain or subgrain size but the strength of the 20 V TiB2NiAl composite was the same as 20 V TiB2 made by the XDTM process. Also, a 0 V TiB2NiAl composite produced from cryomilled NiAl was about the same strength as the 20 V TiB2NiAl composites. The above mentioned composites were made by HIPPing and extrusion. If the 0 V TiB2NiAl cryomilled composite is tested in the as HIPPed condition, the strength is much greater. A TEM investigation has shown that in case of extruded cryomilled composites there is a dispersion of small 10-20 nm Al203 and AIN particles. In the case of the as HIPPed cryomilled composite the Al2O3 and AIN formed a network at the grain boundaries.

Subject Categories:

  • Laminates and Composite Materials
  • Metallurgy and Metallography

Distribution Statement:

APPROVED FOR PUBLIC RELEASE