TY - JOUR
T1 - Reactive infiltration processing and secondary compressive creep of NiAl and NiAl-W composites
AU - Venkatesh, T. A.
AU - Dunand, D. C.
N1 - Funding Information:
This work was supported by the National Science Foundation through Grant No. MSS 9201843, monitored by Dr. B. McDonald. TAV and DCD acknowledge the financial support of the Department of Materials Science and Engineering, MIT, in the form of teaching assistantships and the AMAX career development chair, respectively. The authors also thank Professor A. Mortensen and Dr. C. San Marchi for many helpful discussions and Professor R. Ballinger and Messrs. D. Grundy and P. Stahl for assistance with creep testing of tungsten fibers. TAV acknowledges Professor S. Suresh for funding in the form of a postdoctoral position at MIT during which time the preparation of this manuscript was completed.
PY - 2000
Y1 - 2000
N2 - Reactive infiltration processing was used to fabricate bulk NiAl and fiber-reinforced NiAl composites. Homogenous, pore-free materials were obtained by chemical reaction between nickel and aluminum after complete infiltration with liquid aluminum of preforms of nickel wires (containing tungsten wires for the composites) with low surface-to-volume ratio, high permeability, and regular infiltration paths. Reactively-processed, monolithic NiAl exhibited compressive creep properties at 715 °C and 1025 °C in good agreement with those of conventionally processed NiAl. The compressive creep behavior of NiAl composites reinforced with 5 to 20 vol pct W was also characterized at the same temperatures. At 715 °C, the NiAl-W composites exhibited secondary creep with little primary and tertiary creep, while at 1025 °C, the composites displayed all three stages. Microstructurally, secondary creep was characterized by pure uniaxial compression of tungsten fibers. The measured composite secondary creep rates could be predicted reasonably well with the role-of-mixtures isostrain model developed for composites where both phases undergo creep deformation using tensile creep data measured on the as-received tungsten fibers.
AB - Reactive infiltration processing was used to fabricate bulk NiAl and fiber-reinforced NiAl composites. Homogenous, pore-free materials were obtained by chemical reaction between nickel and aluminum after complete infiltration with liquid aluminum of preforms of nickel wires (containing tungsten wires for the composites) with low surface-to-volume ratio, high permeability, and regular infiltration paths. Reactively-processed, monolithic NiAl exhibited compressive creep properties at 715 °C and 1025 °C in good agreement with those of conventionally processed NiAl. The compressive creep behavior of NiAl composites reinforced with 5 to 20 vol pct W was also characterized at the same temperatures. At 715 °C, the NiAl-W composites exhibited secondary creep with little primary and tertiary creep, while at 1025 °C, the composites displayed all three stages. Microstructurally, secondary creep was characterized by pure uniaxial compression of tungsten fibers. The measured composite secondary creep rates could be predicted reasonably well with the role-of-mixtures isostrain model developed for composites where both phases undergo creep deformation using tensile creep data measured on the as-received tungsten fibers.
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U2 - 10.1007/s11661-000-0020-7
DO - 10.1007/s11661-000-0020-7
M3 - Article
AN - SCOPUS:0033876476
SN - 1073-5623
VL - 31
SP - 781
EP - 792
JO - Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science
JF - Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science
IS - 3
ER -