Microstructural observations in rapidly-solidified and heat-treated Ni sub 3 Al-Cr alloys

Journal Article · Wed Jan 01 00:00:00 EST 1992 · Acta Metallurgica; (United States)

OSTI ID:7280162

Carro, G; Flanagan, W F ^[1]

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1. Dept. of Materials Science, Vanderbilt Univ., Nashville, TN (US)

In this paper , the microstructural development following heat treatments of several rapidly-solidified Ni{sub 3}Al-Cr and Ni{sub 3}Al-Cr-B alloys is presented. Depending on composition, the as-solidified samples were either 100% {gamma} phase-in the form of fine anti-phase domains (APD)-or a mixture of {gamma} (APDs) and {beta} phases. Upon annealing, the as-solidified microstructures transform to either APD-free {gamma}or mixtures of {gamma}and {gamma}{prime} phases. For those compositions where the quenched microstructures were 100{gamma}{prime} it was observed that APD coarsening followed conventional grain-growth kinetics, but when {gamma} phase precipitated on the APD boundaries the rate constant changed abruptly while the time exponent remained unaffected. It was also found that alloys containing critical amounts of chromium and boron are susceptible to precipitation of the boride Cr{sub 5}B{sub 3}.

• OSTI ID: 7280162
• Journal Information: Acta Metallurgica; (United States), Vol. 40:8; ISSN 0001-6160
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM ALLOYS
MICROSTRUCTURE
BORON ALLOYS
CHROMIUM ALLOYS
NICKEL ALLOYS
CHEMICAL COMPOSITION
CHROMIUM BROMIDES
HEAT TREATMENTS
PHASE STUDIES
PRECIPITATION
QUATERNARY ALLOY SYSTEMS
SOLIDIFICATION
TERNARY ALLOY SYSTEMS
TIME DEPENDENCE
ALLOY SYSTEMS
ALLOYS
BROMIDES
BROMINE COMPOUNDS
CHROMIUM COMPOUNDS
CRYSTAL STRUCTURE
HALIDES
HALOGEN COMPOUNDS
PHASE TRANSFORMATIONS
SEPARATION PROCESSES
TRANSITION ELEMENT COMPOUNDS
360102* - Metals & Alloys- Structure & Phase Studies
360106 - Metals & Alloys- Radiation Effects
360202 - Ceramics
Cermets
& Refractories- Structure & Phase Studies