Effects of reinforcement morphology on the fatigue and fracture behavior of MoSi2/Nb composites

Soboyejo, W. O.; Ye, F.; Chen, L.-C.; Bahtishi, Nedhal; Schwartz, Daniel S.; Lederich, R. J.

doi:10.1016/1359-6454(95)00272-3

Cited by 53 publications

(25 citation statements)

References 24 publications

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“…The additional energy required to fracture the bridging ligaments is typically exhibited in the form of resistance-curve (R-curve) behaviour, where the crackgrowth toughness increases with crack extension, commensurate with the development of a bridging zone in the crack wake ( figure 5a,b). In fact, R-curve behaviour has been widely reported in other laminated metalceramic systems (Shaw et al 1993;Rao et al 1994;Soboyejo et al 1996;Bloyer et al 1998;Hwu & Derby 1999b;Rohatgi et al 2003;Mekky & Nicholson 2006). Specifically, the 25/50 hybrid composites reach a (steady-state) fracture toughness K Jc of approximately 40 MPa p m (J c approx.…”

Section: Strength and Fracture Toughnessmentioning

confidence: 99%

“…However, for the same volume fraction of ductile reinforcing phase, the ductile phase in laminate form has the maximum toughening efficiency, followed (in order of potency) by fibre and particulate morphologies (Rao et al 1992;Soboyejo et al 1996). Specifically, the concept of laminating various metals and alloys resulting in composites that exploit the unique properties of the constituent materials has been known for a long time (Leichter 1966), and has been embraced as a potential new engineering concept (Lesuer et al 1996).…”

Section: Introductionmentioning

confidence: 99%

“…Specifically, the concept of laminating various metals and alloys resulting in composites that exploit the unique properties of the constituent materials has been known for a long time (Leichter 1966), and has been embraced as a potential new engineering concept (Lesuer et al 1996). Over the past two decades, a number of diverse brittle ceramics and intermetallics have been toughened with various ductile metal laminates Bannister & Ashby 1991;Cao & Evans 1991;Odette et al 1992;Shaw et al 1993;Alman et al 1995;Huang & Zhang 1995;Heathcote et al 1996;McNaney et al 1996;Rawers & Perry 1996;Soboyejo et al 1996;Bloyer et al 1998;Enoki et al 1999;Fox & Ghosh 1999;Hwu & Derby 1999a,b;Rohatgi et al 2003). A number of these laminate systems were originally conceived and developed with the aim of increasing crack-propagation resistance in brittle components used for high-temperature applications.…”

Section: Introductionmentioning

confidence: 99%

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A novel biomimetic approach to the design of high-performance ceramic–metal composites

Launey

Munch

Alsem

et al. 2009

J. R. Soc. Interface.

249

121

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The prospect of extending natural biological design to develop new synthetic ceramicmetal composite materials is examined. Using ice-templating of ceramic suspensions and subsequent metal infiltration, we demonstrate that the concept of ordered hierarchical design can be applied to create fine-scale laminated ceramic -metal (bulk) composites that are inexpensive, lightweight and display exceptional damage-tolerance properties. Specifically, Al 2 O 3 /Al -Si laminates with ceramic contents up to approximately 40 vol% and with lamellae thicknesses down to 10 mm were processed and characterized. These structures achieve an excellent fracture toughness of 40 MPa p m at a tensile strength of approximately 300 MPa. Salient toughening mechanisms are described together with further toughening strategies.

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Section: Strength and Fracture Toughnessmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

A novel biomimetic approach to the design of high-performance ceramic–metal composites

Launey

Munch

Alsem

et al. 2009

J. R. Soc. Interface.

249

121

View full text Add to dashboard Cite

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“…Homogeneous dispersion of wellaligned columnar ductile phase would impart better toughness in the brittle matrix along a certain direction, compared with the random orientation dispersion of ductile phase. 41,48) A formation of well-aligned eutectic lamellar microstructure would be realized by applying directional solidification technique to the eutectic alloys, while the arc-casting process provides only random configuration of the eutectic microstructure.…”

Section: Microstructures Of Directionally Solidified Alloysmentioning

confidence: 99%

“…6) alloys, however, only a few studies have been made with emphasis on controlling the A2/D8 l lamellar microstructure formed by the eutectoid reaction of tP32 phase 23,39,40) Microstructural control to form alternating layers of ductile/brittle phases is one option for enhancing room temperature toughness of the alloys. 14,15,20,25,41,42) The major interest of the present study is in microstructural control through eutectoid reaction of tP32 phase. This basic strategy extends to the Nb-Ti-Si ternary system, in which improvement in room temperature toughness and oxidation resistance can be expected.…”

Section: Introductionmentioning

confidence: 99%

Solidification Process and Mechanical Behavior of the Nb/Nb<sub>5</sub>Si<sub>3</sub> Two Phase Alloys in the Nb-Ti-Si System

et al. 2004

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Design of two-phase alloys consisting of niobium solid solution (A2) and -Nb 5 Si 3 (D8 l ) phases in the Nb-Ti-Si ternary system is pursued for ultra-high temperature structural applications. Compositional and annealing conditions are determined for the formation of A2/D8 l lamellar microstructure via eutectoid decomposition of Nb 3 Si (tP32) phase in the Nb-Si binary and Nb-Ti-Si ternary system. Addition of titanium is found to result in increased room temperature toughness, but decreased high temperature strength. Enhancement of mechanical properties is achieved by applying the directional solidification technique. Mechanical properties of the alloys are discussed from microstructural point of view.

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Microstructure and Mechanical Properties of Directionally Solidified Nb‐22Ti‐16Si‐7Cr‐3Al‐3Ta‐2Hf‐0.1Ho Alloy

et al. 2007

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Compared to commercial Ni-based superalloy, Niobium silicides possess higher melting point, relatively lower density and excellent high-temperature strength. The attractive combination of properties makes Niobium silicides one of the promising candidates of the next generation materials for high-temperature structural applications. [1][2][3] However, the low ductility and toughness of Niobium silicides at room temperature have limited its practical applications as a structural material. Therefore, it is necessary to simultaneously improve toughness and high-temperature strength of this material to meet the requirement of engineering application. Directional solidification and alloying are usual approaches to achieve these goals. Previous studies showed that one approach to achieving ductility in Ni 3 Al was to directionally solidify samples to eliminate transverse boundaries. [4,5] It was also reported that directional solidification simultaneously improved room temperature toughness and high temperature strength of the Nb-17.5Si and Nb-10Ti-17.5Si. [6] In addition, our previous study showed that the addition of Ho to Nb22Ti-16Si-7Cr-3Al-3Ta-2Hf alloy increased its strength and ductility at the same time. [7] But the ductility of the alloy has not met requirement of practical application. To improve further the strength and ductility of Nbss/Nb 5 Si 3 composites, we combined the above-mentioned two benefits into one system. The aim of the paper is to study microstructure and mechanical properties of directionally solidified Nb-22Ti-16Si-7Cr-3Al-3Ta-2Hf alloy with 0.1 at.% Ho. ExperimentalThe master alloy with the nominal composition Nb-22Ti-16Si-7Cr-3Al-3Ta-2Hf-0.1Ho (at.%) was prepared by arcmelted using a non-consumable tungsten electrode under an argon atmosphere in a water-cooled copper crucible from starting materials of high pure Nb, Ti, Si, Cr, Al, Ta, Hf and Ho. The alloy button was remelted at least five times to ensure a homogeneous specimen. The master rods used for directional solidification were cut from the button by electrodischarge machining (EDM). The dimensions of the rods are 8 mm in diameter and 70 mm in length. Directional solidification experiments were performed in an optical floating zone (OFZ) furnace at the growth rates of 9 mm/h under an Ar gas flowing atmosphere. Microstructural analysis was performed by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). Mechanical properties of the alloy were evaluated by fracture toughness measurement and high-temperature compression tests. Three-point bending tests were performed using single notched specimens with the dimensions 3, 6 and 30 mm in thickness, width and length, respectively. A single notch with about a 3 mm length was introduced at half of the length by EDM with 0.1 mm diameter wire, while not pre-cracked. The tests were executed with a span of 24 mm and at an initial crosshead speed of 0.5 mm/min in air. After the tests, the fracture surfaces and side planes were examined by SEM. The compression specim...

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Effects of reinforcement morphology on the fatigue and fracture behavior of MoSi2/Nb composites

Cited by 53 publications

References 24 publications

A novel biomimetic approach to the design of high-performance ceramic–metal composites

A novel biomimetic approach to the design of high-performance ceramic–metal composites

Solidification Process and Mechanical Behavior of the Nb/Nb<sub>5</sub>Si<sub>3</sub> Two Phase Alloys in the Nb-Ti-Si System

Microstructure and Mechanical Properties of Directionally Solidified Nb‐22Ti‐16Si‐7Cr‐3Al‐3Ta‐2Hf‐0.1Ho Alloy

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