Solid state amorphization reactions in deformed Ni--Zr multilayered composites

Journal Article · Thu Mar 01 04:00:00 EST 1990 · Journal of Materials Research; (USA)

DOI:https://doi.org/10.1557/JMR.1990.0488· OSTI ID:6906718

Wong, G C; Johnson, W L; Cotts, E J ^[1]

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1. Keck Laboratory, California Institute of Technology, Pasadena, California 91125 (USA)

The mechanisms of metallic glass formation and competing crystallization processes in mechanically-deformed Ni--Zr multilayered composites have been investigated by means of differential scanning calorimetry and x-ray diffraction. Our investigation of the heat of formation of amorphous Ni{sub {ital x}}Zr{sub 1{minus}{ital x}} alloys shows a large negative heat of mixing (on the order of 30 kJ/mole) for compositions near Zr{sub 55}Ni{sub 45} with a compositional dependence qualitatively similar to that predicted by mean field theory. We find that the products of solid state reactions in composites of Ni and Zr can be better understood in terms of the equilibrium phase diagram and the thermal stability of liquid quenched metallic glasses. We have determined the composition of the growing amorphous phase at the Zr interface in these Ni--Zr diffusion couples to be 55{plus minus}4% Zr. We investigated the kinetics of solid state reactions competing with the solid state amorphization reaction and found the value of the activation energy of the initial crystallization and growth of the growing amorphous phase to be 2.0{plus minus}0.1 eV, establishing an upper limit on the thermal stability of the growing amorphous phase.

• DOE Contract Number: AS03-81ER10870
• OSTI ID: 6906718
• Journal Information: Journal of Materials Research; (USA), Journal Name: Journal of Materials Research; (USA) Vol. 5:3; ISSN JMREE; ISSN 0884-2914
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360102* -- Metals & Alloys-- Structure & Phase Studies
ALLOYS
CALORIMETRY
CHEMICAL COMPOSITION
CHEMICAL REACTIONS
COHERENT SCATTERING
COMPOSITE MATERIALS
CRYSTALLIZATION
DIFFERENTIAL THERMAL ANALYSIS
DIFFRACTION
ENTHALPY
FORMATION HEAT
MATERIALS
METALLIC GLASSES
NICKEL ALLOYS
ORDER-DISORDER TRANSFORMATIONS
PHASE TRANSFORMATIONS
PHYSICAL PROPERTIES
REACTION HEAT
SCATTERING
THERMAL ANALYSIS
THERMODYNAMIC PROPERTIES
X-RAY DIFFRACTION
ZIRCONIUM ALLOYS