scholarly journals Influence of Ti Addition on the Strengthening and Toughening Effect in CoCrFeNiTix Multi Principal Element Alloys

Metals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1511
Author(s):  
Dukhyun Chung ◽  
Heounjun Kwon ◽  
Chika Eze ◽  
Woochul Kim ◽  
Youngsang Na
Keyword(s):  
Fracture Toughness ◽  
High Fracture Toughness ◽  
Molar Ratio ◽  
Cubic Phase ◽  
Face Centered Cubic ◽  
Secondary Phases ◽  
High Fracture ◽  
Principal Element ◽  
Multi Phase ◽  
Ti Addition

Multi principal element alloys have attracted interests as a promising way to balance the bottleneck of the “inverse relationship” between high hardness and high fracture toughness. In the present study, the authors demonstrate the effects of Ti addition on the microstructures and mechanical properties of the CoCrFeNiTix alloys (x values in molar ratio, x = 0.7, 1.0, and 1.2), which exhibits a multi-phase structure containing face-centered cubic phase and various secondary phases, such as sigma, Laves, and (Cr,Fe)-rich phase. Throughout the combined experimental examination and modeling, we show that superb hardness (~9.3 GPa) and excellent compressive strength (~2.4 GPa) in our alloy system are attributed to solid-solution strengthening of the matrix and the formation of hard secondary phases. In addition, high indentation fracture toughness is also derived from the toughening mechanism interplay within the multiple-phase microstructure. At the fundamental level, the results suggest that multi-principal element alloys containing dual or multi-phase structures may provide a solution for developing structural alloys with enhanced strength-toughness synergy.

Composition Modification and Mechanical Properties of Solidified TiB2-Based Ceramic Prepared by Combustion Synthesis in Ultra-High Gravity Field

2013 ◽  
Vol 591 ◽  
pp. 79-83
Author(s):  
Xue Gang Huang ◽  
Zhong Min Zhao ◽  
Long Zhang
Keyword(s):  
Fracture Toughness ◽  
High Fracture Toughness ◽  
Full Density ◽  
High Gravity ◽  
Secondary Phases ◽  
High Fracture ◽  
Pull Out ◽  
Refined Microstructure ◽  
High Gravity Field ◽  
Additional Agent

The solidified TiC-TiB2 ceramics with excessive Ti mole content were prepared through adjusting the Ti additional agent in combustion system with ultra-high-gravity of 2000 g, and the ceramics were comprised of TiB2 primary phases, irregular TiC1-x secondary phases, a few of Al2O3 inclusions and Cr-Ti-Al metallic phases. The additional Ti content resulted in not only the rapidly-reduced Al2O3 inclusions but also the refined microstructure and the improved homogeneity in the solidified microstructure. As the Ti additional agent was increased, more and more Ti atoms could participate in the formation of nonstoichiometric TiC1-x phases and Cr-Ti-Al metallic phases. The maximum fracture toughness of 18.5 ± 1.0 MP · m0.5 in current solidified TiC-TiB2composite was achieved because of the less Al2O3 inclusions, the refined microstructure and the Ti-rich Cr-Ti-Al metallic phases obtained in the near-full-density composite. The high fracture toughness contributed from not only mechanism of crack deflection, crack-bridging and pull-out by a large number of fine TiB2 platelets, but also the ductile fracture toughening result from plastic deformation of Cr-Ti-Al metallic phases.

Microstructure and Mechanical Property of Zirconia Nanocomposites

2010 ◽  
Vol 434-435 ◽  
pp. 594-596 ◽  
Author(s):  
Wen Xu Li ◽  
De Zhen Yu ◽  
Fu Ping Wang
Keyword(s):  
Mechanical Property ◽  
Fracture Toughness ◽  
Flexural Strength ◽  
Dental Restoration ◽  
High Fracture Toughness ◽  
Cubic Phase ◽  
High Fracture ◽  
Nano Size ◽  
Size Powder ◽  
Ceramic Nanocomposites

ZrO2 nanocomposites were prepared and studied by microstructure observation and mechanical property detection. First, yttria stabilized zirconia (3Y-TZP) nanopowders were synthesized by sol-gel method. TEM photograph showed that the addition of yttria restrained the growth of the grain, but caused the agglomeration of the nanopowder. XRD analysis showed that the amount of yttria influenced the phase character of the materials, and the monoclinic zirconia changed gradually into tetragonal and cubic phase with increasing yttria content. Second, the micro-size 3Y-TZP materials was mixed with the former prepared nano-size particles and pressed by cold isostatic pressing, and then sintered at 1300 °C to prepare ZrO2 ceramic nanocomposites. The results of microstructure analysis showed that the amount of nano-size powder affected the fracture mode of nanocomposites, thus changed the fracture toughness. The mechanical testing results indicated that both the flexural strength and the hardness decreased with increasing nano-size powder, whereas fracture toughness increased and decreased subsequently. ZrO2 ceramic nanocomposites with 20% nano-size powder would be a promising kind of dental restoration material due to its low hardness, high fracture toughness and moderate flexural strength.

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.

Development of Build-up Dielectric Material that enables High Temp. Low Loss, High Fracture Toughness Advanced FC-BGA Substrates

2021 ◽  
Author(s):  
Tatsushi Hayashi ◽  
Pochao Chang ◽  
Ryoichi Watanabe ◽  
Seiko Ichikawa ◽  
Eita Horiki
Keyword(s):  
Fracture Toughness ◽  
Dielectric Material ◽  
High Fracture Toughness ◽  
Low Loss ◽  
High Fracture

Influence of additive composition on thermal and mechanical properties of β–Si3N4 ceramics

2004 ◽  
Vol 19 (11) ◽  
pp. 3270-3278 ◽  
Author(s):  
Xinwen Zhu ◽  
Hiroyuki Hayashi ◽  
You Zhou ◽  
Kiyoshi Hirao
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Fracture Toughness ◽  
Nitrogen Pressure ◽  
High Fracture Toughness ◽  
Oxygen Impurity ◽  
Thermal And Mechanical Properties ◽  
High Fracture ◽  
Doped Materials ◽  
Gas Pressure Sintering

Dense β–Si3N4 ceramics were fabricated from α–Si3N4 raw powder by gas-pressure sintering at 1900 °C for 12 h under a nitrogen pressure of 1 MPa, using four different kinds of additive compositions: Yb2O3–MgO, Yb2O3–MgSiN2, Y2O3–MgO, and Y2O3–MgSiN2. The effects of additive composition on the microstructure and thermal and mechanical properties of β–Si3N4 ceramics were investigated. It was found that the replacement of Yb2O3 by Y2O3 has no significant effect on the thermal conductivity and fracture toughness, but the replacement of MgO by MgSiN2 leads to an increase in thermal conductivity from 97 to 113 Wm-1K-1and fracture toughness from 8 to 10 MPa m1/2, respectively. The enhanced thermal conductivity of the MgSiN2-doped materials is attributed to the purification of β–Si3N4 grain and increase of Si3N4–Si3N4 contiguity, resulting from the enhanced growth of large elongated grains. The improved fracture toughness of the MgSiN2-doped materials is attributed to the increase of grain size and fraction of large elongated grains. However, the same thermal conductivity between the Yb2O3- and Y2O3-doped materials is related to not only their similar microstructures, but also the similar abilities of removing oxygen impurity in Si3N4 lattice between Yb2O3 and Y2O3. The same fracture toughness between the Yb2O3- and Y2O3-doped materials is consistent with their similar microstructures. This work implies that MgSiN2 is an effective sintering aid for developing not only high thermal conductivity (>110 Wm−1K−1) but also high fracture toughness (>10 MPa m1/2) of Si3N4 ceramics.

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