40 Result(s)
within
K.S. Chan
Materials Science
Surfaces and Interfaces, Thin Films
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Article
MicroROM: A Physics-Based Constitutive Model for Ni-Based Superalloys
In this article, a physics-based constitutive model is developed for representing the stress–plastic strain response of Ni-based superalloys by considering the hardening mechanisms that contribute to the macro...
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Article
Fatigue Crack Prognostics by Optical Quantification of Defect Frequency
Defect frequency, a fatigue crack prognostics indicator, is defined as the number of microcracks per second detected using a laser beam that is scanned across a surface at a constant predetermined frequency. I...
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Article
Evolution of Slip Morphology and Fatigue Crack Initiation in Surface Grains of Ni200
The evolution of slipbands into fatigue cracks in surface grains of commercially pure Ni, Ni200 (99.35Ni-0.4Fe-0.25Cu, in wt pct), was studied at ambient temperature. Round-bar specimens with electropolished s...
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Article
In-Situ Fracture Studies and Modeling of the Toughening Mechanism Present in Wrought Low-Carbon Arc-Cast Molybdenum, Titanium-Zirconium-Molybdenum, and Oxide-Dispersion-Strengthened Molybdenum Flat Products
In-situ testing, ultrasonic C-scans, and metallography were used to show that a crack-divider delamination form of thin-sheet toughening occurs in wrought low-carbon arc-cast (LCAC) unall...
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Article
Effects of Deformation-Induced Constraint on High-Cycle Fatigue in Ti Alloys with a Duplex Microstructure
The effects of the deformation behaviors of individual phases in Ti alloys with a duplex microstructure containing a mixture of primary α grains and lamellar α + β colonies have been analyzed by applying the fini...
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Article
An Experimental Study of Fracture of LIGA Ni Micro-Electro-Mechanical Systems Thin Films
This article presents the results of an experimental study of fracture in LIGA Ni micro-electro-mechanical systems (MEMS) thin films. Microtesting techniques are developed for the study of the J-resistance curve ...
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Article
Durability of Fe-Co thin films on Ti-6Al-4V
The durability of Fe-Co thin films bonded on Ti-6Al-4V was studied as a function of layer thickness at ambient temperature. Interface toughness of the thin films was characterized by indentation and analyzed u...
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Article
First-principles computations of mechanical properties of Ni2Cr and Ni2Mo
Nickel-based alloys are being considered for use as the outer container of the waste package for the disposal of high-level nuclear waste. During fabrication processes and long-term storage, Ni-based alloy out...
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Article
Microstructural and fracture characterization of Nb-Cr-Ti mechanically alloyed materials
Three materials containing Nb, Cr, and Ti were fabricated by consolidating powders made by mechanical alloying. The Nb/Ti ratio was maintained at about 1.3 and Cr was increased to form the intermetallic Cr2Nb. X-...
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Article
Constitutive properties of hard-alpha titanium
The flow and fracture behavior of hard-alpha Ti was studied as a function of nitrogen content, stress state, strain rate, and temperature. Hard-alpha Ti specimens with nitrogen contents ranging from 2 to 11.6 ...
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Article
Fatigue and fracture toughness of a Nb-Ti-Cr-Al-X single-phase alloy at ambient temperature
The fatigue and fracture resistance of a commercially made, single-phase Nb-base alloy with 35 at. pct Ti, 5 at. pct Cr, 6 at. pct Al, and several elements to increase solid solution strengthening have been in...
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Article
The fatigue and fracture resistance of a Nb-Cr-Ti-Al alloy
The microstructure, fatigue, and fracture behaviors of a cast and heat-treated Nb-Cr-Ti-Al alloy were investigated. The microstructure of the cast alloy was manipulated by annealing at a temperature ranging fr...
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Article
Fundamental aspects of fatigue and fracture in a TiAl sheet alloy
The fatigue mechanisms in a TiAl sheet alloy, heat treated to the lamellar and equiaxed microstructures, were studied to determine the effects of microstructure on the initiation of microcracks and their subse...
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Article
Fracture toughness and fatigue crack growth in rapidly quenched Nb-Cr-Ti In situ composites
In situ composites based on the Nb-Cr-Ti ternary system were processed by rapid solidification in order to reduce the size of the reinforcing intermetallic phase. Two-phase microstructures with s...
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Article
The effects on fracture toughness of ductile-phase composition and morphology in Nb-Cr-Ti and Nb-Siin situ composites
Niobium-chromium alloys, both single and two phase, were alloyed with titanium in order to enhance fracture toughness and fatigue crack growth resistance. The selection of titanium as an alloying element and t...
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Article
Cu-bearing high-strength low-alloy steels: The influence of microstructure on the initiation and growth of small fatigue cracks
The fatigue characteristics of a Cu-bearing high-strength low-alloy (HSLA) steel were investigated in air, relative humidity ≈50 pct, as a function of microstructure, which was altered by heat treatments and w...
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Article
Relationships of slip morphology, microcracking, and fracture resistance in a lamellar TiAl-alloy
The fracture resistance of a lamellar TiAl-alloy was investigated by J-testing under various displacement rates at ambient temperature. Possible relationships between slip morphology, microcracking, and fractu...
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Article
Tensile ductility of extrinsically toughened intermetallics
A theoretical analysis based on crack instability is presented to elucidate factors effecting the tensile ductility of intermetallics that are toughened by extrinsic mechanisms and resistance-curve effects. Th...
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Article
Scaling Laws for Fatigue Crack Growth of Large Cracks in Steels
A set of scaling laws has been developed for describing intermittent as well as continuous fatigue crack growth of large cracks in steels in the power-law regime. The proposed scaling laws are developed on the...
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Article
Erratum to: Failure Diagrams for Unidirectional Fiber Metal Matrix Composites
