Fracture strength and fracture toughness of graphene: MD simulations

2021 ◽  
Vol 127 (12) ◽  
Author(s):  
V. K. Sutrakar ◽  
B. Javvaji ◽  
P. R. Budarapu
Keyword(s):  
Fracture Toughness ◽  
Fracture Strength ◽  
Md Simulations

Microstructure Development and Mechanical Properties of Ce-TZP/La- β-Alumina Composites

1992 ◽  
Vol 274 ◽  
Author(s):  
Takashi Fujii ◽  
Hironobu Muragaki ◽  
Hiraku Hatano ◽  
Shin-Ichi Hirano
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Hydrothermal Treatment ◽  
Fracture Strength ◽  
Sintered Body ◽  
Microstructure Development ◽  
Lanthanum Aluminate ◽  
Alumina Composites ◽  
In Situ Formation

ABSTRACTSimultaneous additions of lanthanum aluminate(LAL) and Al2O3 to Ce-TZP (12mol% CeO2-ZrO2) lead to the in-situ formation of lanthanum- β-alumina(LBA) platelets (∼1.0.μ m in width and 5 ∼10 μ m in length) in the Ce-TZP matrix during sintering. The composites showed a fracture toughness(SEPB method) of 9.5 MPa · m0.5 and fracture strength of 960 MPa. which are remarkably improved from Ce-TZP sintered body (8.5 MPa · m0.5 and 560 MPa).The composites also exhibit the no degradation by hydrothermal treatment.

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.

Parameters on Fracture Strength of Sea Ice

1983 ◽  
Vol 105 (1) ◽  
pp. 12-16 ◽  
Author(s):  
N. Urabe ◽  
A. Yoshitake ◽  
T. Iwasaki ◽  
M. Kawahara
Keyword(s):  
Fracture Toughness ◽  
Sea Ice ◽  
Strain Rate ◽  
Fracture Strength ◽  
Test Procedure ◽  
Standard Test ◽  
Test Method ◽  
Beam Specimen ◽  
Crushing Strength ◽  
Brackish Ice

Compressive crushing strength on brackish ice and sea ice and fracture toughness value on sea ice were measured as parameters associated with fracture strength of ice. The compressive crushing strength depends on salinity, temperature and strain rate. At constant salinity and temperature, the strength increased with increase in strain rate and reached maximum value at about a strain rate of 10−3 s−1, then decreased with increase in strain rate. An empirical equation to estimate the compressive crushing strength was derived as a function of brine volume, temperature and strain rate. As far as fracture toughness is concerned, a simplified test procedure on notched cantilever beam specimen was developed in order to avoid complicated manipulation in field conditions. The fracture toughness value (KIC) coincided well with the value obtained from fracture toughness tests conducted in conformity with the standard test method.

High Strength and Toughness Al2O3 Composite Materials for the Improvement of Ceramic Channel in SRL Hot Dipping System

2010 ◽  
Vol 658 ◽  
pp. 416-419 ◽  
Author(s):  
Hyun Hwi Lee ◽  
Seung Ho Kim ◽  
Bhupendra Joshi ◽  
Sung Hun Cho ◽  
Soo Wohn Lee
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Composite Materials ◽  
Flexural Strength ◽  
Fracture Strength ◽  
Hot Pressing ◽  
High Strength ◽  
Economic Feasibility ◽  
Different Content ◽  
Strength And Toughness

The ceramic channel is very important in SRL hot dipping system. High strength and fracture toughness of ceramic channel materials can improve the quality, productivity and economic feasibility of zinc plated steel. The purpose of this research was to find out the most suitable conditions of the ceramic channel that have best fracture strength and fracture toughness. The hot pressed composite materials was carried out by hot pressing Al2O3 with different content of ZrO2. The composite contained from 0-20 wt.% ZrO2. Hot pressed composite materials were observed for mechanical properties (density, hardness, fracture toughness and flexural strength) and microstructure.

Mechanical Properties of Transparent Polycrystalline Silicon Nitride

2006 ◽  
Vol 317-318 ◽  
pp. 305-308 ◽  
Author(s):  
Rak Joo Sung ◽  
Takafumi Kusunose ◽  
Tadachika Nakayama ◽  
Yoon Ho Kim ◽  
Tohru Sekino ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Silicon Nitride ◽  
Young’S Modulus ◽  
Fracture Strength ◽  
Polycrystalline Silicon ◽  
Volume Fraction ◽  
Young's Modulus ◽  
Β Phase ◽  
Α Phase

A novel transparent polycrystalline silicon nitride was fabricated by hot-press sintering with MgO and AlN as additives. The mixed powder with 3 wt.% MgO and 9 wt.% AlN was sintered at 1900oC for 1 hour under 30 MPa pressure in a nitrogen gas atmosphere. Transparent polycrystalline silicon nitride was successfully fabricated. The mechanical properties such as density, hardness, young’s modulus, fracture strength and fracture toughness were evaluated. The effect of α/β phase on the mechanical properties of transparent polycrystalline silicon nitride was investigated. The properties were changed depending on the amount of α/β phase. The hardness and Young's modulus increased with increasing the volume fraction of α-phase fraction as a reflection of the higher hardness of α-phase Si3N4. The fracture toughness and fracture strength decreased with decreasing the volume fraction of β-phase Si3N4.

scholarly journals How the toughness in metallic glasses depends on topological and chemical heterogeneity

2016 ◽  
Vol 113 (26) ◽  
pp. 7053-7058 ◽  
Author(s):  
Qi An ◽  
Konrad Samwer ◽  
Marios D. Demetriou ◽  
Michael C. Floyd ◽  
Danielle O. Duggins ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Metallic Glasses ◽  
Energy Barrier ◽  
Crack Nucleation ◽  
Chemical Separation ◽  
Md Simulations ◽  
Chemical Heterogeneity ◽  
Chemical Inhomogeneity ◽  
Critical Factors ◽  
Insight Into

To gain insight into the large toughness variability observed between metallic glasses (MGs), we examine the origin of fracture toughness through bending experiments and molecular dynamics (MD) simulations for two binary MGs: Pd82Si18 and Cu46Zr54. The bending experiments show that Pd82Si18 is considerably tougher than Cu46Zr54, and the higher toughness of Pd82Si18 is attributed to an ability to deform plastically in the absence of crack nucleation through cavitation. The MD simulations study the initial stages of cavitation in both materials and extract the critical factors controlling cavitation. We find that for the tougher Pd82Si18, cavitation is governed by chemical inhomogeneity in addition to topological structures. In contrast, no such chemical correlations are observed in the more brittle Cu46Zr54, where topological low coordination number polyhedra are still observed around the critical cavity. As such, chemical inhomogeneity leads to more difficult cavitation initiation in Pd82Si18 than in Cu46Zr54, leading to a higher toughness. The absence of chemical separation during cavitation initiation in Cu46Zr54 decreases the energy barrier for a cavitation event, leading to lower toughness.

Processing and characterization of B4C-Al laminated cermets

1990 ◽  
Vol 48 (4) ◽  
pp. 1022-1023
Author(s):  
Mehrdad Yasrebi ◽  
Gyeung H. Kim ◽  
David L. Milius ◽  
Mehmet Sarikaya ◽  
Ilhan A. Aksay
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Fracture Strength ◽  
Laminated Composites ◽  
Laminated Composite ◽  
Type A ◽  
Type B ◽  
Body Type ◽  
Metal Infiltration

B4C-Al composites show enhanced fracture strength and fracture toughness values over monolithic B4C.1-2 A controlled change in structural morphologies such as lamination further enhances mechanical properties of the composite over the B4C-Al composites processed to form a monolithic morphology. This paper summarizes microstructure-property correlations studied in B4C-Al laminated composites.The laminated composite is formed either by metal infiltration of B4C tapes sandwiched with Al sheets, type (a), (Fig. 1a) or by lamination of B4C tapes of different porosity and then subjected to metal infiltration of the laminated body, type (b), (Fig. 1b). In the first method, after thin tapes of B4C were formed, each tape was individually sintered between polished graphite discs, then layered with Al sheets, and the entire stack was heated to induce infiltration. In the second method, tapes of B4C with different green densities were stacked and laminated under pressure and temperature. The laminated body was then sintered and subsequently infiltrated with Al.

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