Strengthening of NiAl matrix composites. Annual report, 1 October 1993-30 November 1994

Technical Report · Wed Nov 30 04:00:00 EST 1994

OSTI ID:76285

Arsenault, R J

The significant result is that the observed strengthening due to various types reinforcements (Al203 and TiB2) with same size is almost identical. The smaller size reinforcement 5 micrometers vs 150 micrometers produces greater strengthening. Also, the strengthening due to Al2O3 whiskers, which have long l/d (length to diameter) ratios of 10 to 100 is no greater than particulate Al203 and TiB2 of approximately the same size, which is a further indication that a load transfer mechanism is not applicable for these composites. A detailed examination of the data still suggests that the thermally-activated-rate controlling mechanism is the stress assisted motion of jogged screw dislocations. The specific details of the process are now be worked out to be able to obtain the proper stress and temperature dependence of the activation parameters. The strengthening observed in the composites at both high and low temperatures is due to an increase in the internal stress. This internal stress is independent of test temperature and stress.

• Research Organization: Maryland Univ., College Park, MD (United States). Metallurgical Materials Lab.
• OSTI ID: 76285
• Report Number(s): AD-A--288923/6/XAB; MML--1-1994; CNN: Contract N00014-94-1-0118
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM ALLOYS
ALUMINIUM OXIDES
DUCTILITY
ELASTICITY
MATRIX MATERIALS
NICKEL ALLOYS
PROGRESS REPORT
SCREW DISLOCATIONS
STRESS ANALYSIS
TITANIUM BORIDES
YIELD STRENGTH