Properties of Microlaminated Intermetallic-Refractory Metal Composites

1993 ◽  
Vol 322 ◽  
Author(s):  
R. G. Rowe ◽  
D. W. Skelly ◽  
M. Larsen ◽  
J. Heathcote ◽  
G. Lucas ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Fracture Strength ◽  
Refractory Metal ◽  
Elevated Temperatures ◽  
High Rate ◽  
High Fracture Toughness ◽  
Tensile Fracture ◽  
High Fracture ◽  
Tensile Fracture Strength ◽  
Intermetallic Layers

AbstractMicrolaminated composites of Nb3Al-Nb and Cr2Nb-Nb(Cr) were synthesized by high rate magnetron sputtering. Both composites were stable at elevated temperatures. A Cr2Nb-Nb(Cr) composite with 2 µm metal and intermetallic layers had room temperature tensile fracture strength over 725 MPa and a fracture toughness of about 20 MPa√m. Composites with 2 µm and 6 µm thick refractory metal and intermetallic laminations were compared and it was found that layer thickness did not affect fracture toughness. Microlaminates with the thicker 6 µm laminations had lower fracture strength, however. Good fracture strength and high fracture toughness indicated that microlaminated high temperature composites synthesized by vapor phase deposition exhibit the properties predicted by ductile toughening models.

Enhanced Mechanism of Fracture Toughness in Cannon Bone

2008 ◽  
Vol 368-372 ◽  
pp. 1651-1653
Author(s):  
Bin Chen ◽  
X. Peng ◽  
S. Sun
Keyword(s):  
Fracture Toughness ◽  
Fracture Strength ◽  
Biological Material ◽  
Collagen Matrix ◽  
High Fracture Toughness ◽  
High Fracture ◽  
Sem Observation ◽  
Representative Model ◽  
Parallel Distribution

As a typical biological material, bone possesses high fracture strength and fracture toughness, which are closely related to its exquisite microstructure. SEM observation of a cannon bone shows that the bone is a kind of layered bioceramic composite consisting of hydroxyapatite sheets and collagen matrix. The hydroxyapatite sheets are of long and thin shape, distributing in parallel. The fracture toughness of the bone is analyzed with the representative model of the hydroxyapatite sheets and the concept of maximum pullout energy. It is shown that the lathy shape as well as the parallel distribution of the hydroxyapatite sheets increases the pullout energy and endows the bone with high fracture toughness.

Fabrication of Toughened Alumina Nanocomposites Using γ-Alumina Powder

2006 ◽  
Vol 11-12 ◽  
pp. 583-586
Author(s):  
Seong Min Choi ◽  
Takuya Matsunaga ◽  
Sung Ho Cheon ◽  
Sawao Honda ◽  
Shinobu Hashimoto ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Fracture Strength ◽  
Ceramic Materials ◽  
High Fracture Toughness ◽  
Alumina Powder ◽  
High Fracture ◽  
New Processing ◽  
Monolithic Alumina ◽  
Pulse Electric ◽  
Sintering Method

To improve fracture strength and fracture toughness in ceramic materials, we focused our attention on an intra-type structure of nanocomposites. We proposed new processing method for fabricating intra-type nanocomposites. In this work, Al2O3/Ni nanocomposites were fabricated using a soaking method and sintered by PECS(Pulse Electric Current Sintering) method. We also estimated seed effects on this system. Seeded nanocomposites showed high fracture strength and higher fracture toughness than non-seeded nanocomposites and monolithic alumina. The fracture strength of the seeded nanocomposites was more than 800MPa in all sintering temperature range. The maximum value of the fracture toughness was 5.5 MPa⋅m1/2 for the specimen sintered at 1350°C. The sintered specimens with high fracture strength and high fracture toughness were annealed from 800°C to 1000°C for 0 to 10 min. The specimen annealed at 800°C for 5 min showed the highest fracture toughness of 7.6 MPa⋅m1/2. This value is two times higher than that of the monolithic alumina.

Toughness Analysis of Cannon Bone Based on Microstructural Model

2009 ◽  
Vol 610-613 ◽  
pp. 1066-1069
Author(s):  
Bin Chen ◽  
Shi Tao Sun ◽  
Xiang He Peng
Keyword(s):  
Fracture Toughness ◽  
Fracture Strength ◽  
Biological Material ◽  
Collagen Matrix ◽  
High Fracture Toughness ◽  
High Fracture ◽  
Sem Observation ◽  
Microstructural Model ◽  
Representative Model ◽  
Parallel Distribution

As a typical biological material, bone possesses high fracture strength and fracture toughness, which are closely related to its exquisite microstructure. SEM observation of a cannon bone shows that the bone is a kind of layered bioceramic composite consisting of hydroxyapatite sheets and collagen matrix. The hydroxyapatite sheets are of long and thin shape, distributing in parallel. The fracture toughness of the bone is analyzed with the representative model of the hydroxyapatite sheets and the concept of maximum pullout energy. It is shown that the lathy shape as well as the parallel distribution of the hydroxyapatite sheets increases the pullout energy and endows the bone with high fracture toughness.

KAISER ALUMINUM ALLOY 7050

Alloy Digest ◽  
2000 ◽  
Vol 49 (1) ◽  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Tensile Strength ◽  
Aluminum Alloy ◽  
Heat Treating ◽  
High Fracture Toughness ◽  
High Fracture ◽  
Kaiser Aluminum ◽  
Structural Parts ◽  
Very High

Abstract Kaiser Aluminum Alloy 7050 has very high mechanical properties including tensile strength, high fracture toughness, and a high resistance to exfoliation and stress-corrosion cracking. The alloy is typically used in aircraft structural parts. This datasheet provides information on composition, physical properties, hardness, tensile properties, and shear strength as well as fracture toughness and fatigue. It also includes information on forming, heat treating, machining, and joining. Filing Code: AL-366. Producer or source: Tennalum, A Division of Kaiser Aluminum.

FERRIUM M54

Alloy Digest ◽  
2018 ◽  
Vol 67 (9) ◽  
Keyword(s):  
Fracture Toughness ◽  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
High Resistance ◽  
High Strength ◽  
Cost Effective ◽  
High Fracture Toughness ◽  
High Fracture ◽  
Structural Applications ◽  
Resistance To Stress

Abstract Ferrium M54 was designed to create a cost-effective, ultra high-strength, high-fracture toughness material with a high resistance to stress-corrosion cracking for use in structural applications. This datasheet provides information on composition, hardness, and tensile properties as well asfatigue. Filing Code: SA-822. Producer or source: QuesTek Innovations, LLC.

Fracture of Soft Elastic Foam

2015 ◽  
Vol 83 (3) ◽  
Author(s):  
Zhuo Ma ◽  
Xiangchao Feng ◽  
Wei Hong
Keyword(s):  
Fracture Toughness ◽  
Fracture Energy ◽  
Cell Walls ◽  
Scaling Law ◽  
Phase Field Model ◽  
Base Material ◽  
Network Connectivity ◽  
High Fracture Toughness ◽  
High Fracture ◽  
Order Of Magnitude

Consisting of stretchable and flexible cell walls or ligaments, soft elastic foams exhibit extremely high fracture toughness. Using the analogy between the cellular structure and the network structure of rubbery polymers, this paper proposes a scaling law for the fracture energy of soft elastic foam. To verify the scaling law, a phase-field model for the fracture processes in soft elastic structures is developed. The numerical simulations in two-dimensional foam structures of various unit-cell geometries have all achieved good agreement with the scaling law. In addition, the dependences of the macroscopic fracture energy on geometric parameters such as the network connectivity and spatial orientation have also been revealed by the numerical results. To further enhance the fracture toughness, a type of soft foam structures with nonstraight ligaments or folded cell walls has been proposed and its performance studied numerically. Simulations have shown that an effective fracture energy one order of magnitude higher than the base material can be reached by using the soft foam structure.

scholarly journals Tough metal-ceramic composites with multifunctional nacre-like architecture

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Erik Poloni ◽  
Florian Bouville ◽  
Christopher H. Dreimol ◽  
Tobias P. Niebel ◽  
Thomas Weber ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Sol Gel ◽  
Ceramic Composites ◽  
High Fracture Toughness ◽  
Processing Route ◽  
High Fracture ◽  
Metal Ceramic ◽  
Attractive Option ◽  
Brick And Mortar ◽  
Robotic Applications

AbstractThe brick-and-mortar architecture of biological nacre has inspired the development of synthetic composites with enhanced fracture toughness and multiple functionalities. While the use of metals as the “mortar” phase is an attractive option to maximize fracture toughness of bulk composites, non-mechanical functionalities potentially enabled by the presence of a metal in the structure remain relatively limited and unexplored. Using iron as the mortar phase, we develop and investigate nacre-like composites with high fracture toughness and stiffness combined with unique magnetic, electrical and thermal functionalities. Such metal-ceramic composites are prepared through the sol–gel deposition of iron-based coatings on alumina platelets and the magnetically-driven assembly of the pre-coated platelets into nacre-like architectures, followed by pressure-assisted densification at 1450 °C. With the help of state-of-the-art characterization techniques, we show that this processing route leads to lightweight inorganic structures that display outstanding fracture resistance, show noticeable magnetization and are amenable to fast induction heating. Materials with this set of properties might find use in transport, aerospace and robotic applications that require weight minimization combined with magnetic, electrical or thermal functionalities.

scholarly journals Mechanical Properties of CaO–Al2O3–SiO2 Glass-Ceramics Precipitating Hexagonal CaAl2Si2O8 Crystals

Crystals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 393
Author(s):  
Kei Maeda ◽  
Kosho Akatsuka ◽  
Gaku Okuma ◽  
Atsuo Yasumori
Keyword(s):  
Fracture Toughness ◽  
Liquidus Temperature ◽  
Fracture Behavior ◽  
Glass Ceramics ◽  
High Fracture Toughness ◽  
Flexural Test ◽  
Toughening Mechanism ◽  
High Fracture ◽  
X Ray ◽  
Microcrack Toughening

Fracture behavior via a flexural test for a newly found CaO–Al2O3–SiO2 (CAS) glass-ceramic (GC) was compared with that of enstatite GC and mica GC, which are well-known GCs with high-fracture toughness and machinability, respectively. By focusing on the nonelastic load–displacement curves, CAS GC was characterized as a less brittle material similar to machinable mica GC, compared with enstatite GC, which showed higher fracture toughness, KIC. The microcrack toughening mechanism in CAS GC was supported by the nondestructive observation of microcracks around the Vickers indentation using the X-ray microcomputed tomography technique. The CAS GC also showed higher transparency than mica GC due to its low crystallinity. Moreover, the precursor glass had easy formability due to its low-liquidus temperature.

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