Precipitation strengthening, yield stress anomaly and strain rate sensitivity of an L1{sub 2}-ordered intermetallic (Ni, Co){sub 3}(Al, Ti) alloy

Journal Article · Tue Oct 13 04:00:00 EDT 1998 · Scripta Materialia

DOI:https://doi.org/10.1016/S1359-6462(98)00295-4· OSTI ID:20023126

Liu, W; Krol, T; Nembach, E

The L1{sub 2}-type long-range ordered {gamma}{prime} intermetallic alloys Ni{sub 3}Al, Ni{sub 3}Si and Co{sub 3}Ti have attracted much attention because of their potential as high temperature structural materials. However, such intermetallics suffer from low-temperature brittleness and inadequate high-temperature creep resistance. Recently, efforts have been made to introduce a ductile second phase into the {gamma}{prime} intermetallic alloys, in order to improve their strength, ductility and creep resistance. For this purpose, the new family of quaternary L1{sub 2}-ordered intermetallic alloys (Ni,CO){sub 3} (Al,Ti), (Ni,Co){sub 3} (Si,Ti) and Ni{sub 3}(Al,Si,Ti) has been developed, in which homogeneously distributed, coherent precipitates of the disordered f.c.c. {gamma} phase can be obtained by suitable aging treatments. Precipitation strengthening of {gamma}{prime} intermetallics by the disordered {gamma} phase has been studied on the basis of the interaction of superdislocations with {gamma} precipitates. The objective of the present work was to study the mechanical properties of an L1{sub 2}- ordered intermetallic (Ni,Co){sub 3} (Al,Ti) alloy. Emphasis is placed on the observation of the precipitation process and age hardening as well as on the measurements of the temperature dependence and strain rate sensitivity of the yield stress and flow stress.

• Research Organization: Univ. Muenster (DE)
• OSTI ID: 20023126
• Journal Information: Scripta Materialia, Journal Name: Scripta Materialia Journal Issue: 10 Vol. 39; ISSN 1359-6462; ISSN SCMAF7
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
AGE HARDENING
ALUMINIUM ALLOYS
COBALT ALLOYS
FLOW STRESS
INTERMETALLIC COMPOUNDS
NICKEL ALLOYS
PRECIPITATION
STRAIN RATE
TEMPERATURE DEPENDENCE
TITANIUM ALLOYS
YIELD STRENGTH