Investigating the influence mechanism of hydrogen partial pressure on fracture toughness and fatigue life by in-situ hydrogen permeation

2021 ◽  
Author(s):  
Shuai Zhang ◽  
Juan Li ◽  
Teng An ◽  
Shuqi Zheng ◽  
Ke Yang ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Fatigue Life ◽  
Partial Pressure ◽  
Hydrogen Permeation ◽  
Hydrogen Partial Pressure ◽  
Influence Mechanism

scholarly journals Impact of the in situ rise in hydrogen partial pressure on graphene shape evolution during CVD growth of graphene

RSC Advances ◽  
2018 ◽  
Vol 8 (15) ◽  
pp. 8234-8239 ◽  
Author(s):  
Zewdu M. Gebeyehu ◽  
Aloïs Arrighi ◽  
Marius V. Costache ◽  
Clivia M. Sotomayor-Torres ◽  
Maria J. Esplandiu ◽  
...  
Keyword(s):  
Partial Pressure ◽  
Hydrogen Partial Pressure ◽  
Shape Evolution ◽  
Cvd Growth

Growth to etching transformation following in situ rise in hydrogen with time results in dendritic graphene.

Optimization on Influencing Factors of Fracture Toughness of Corundum-Mullite Toughened by In Situ Synthesized Mullite Whiskers by Response Surface Methodology

2012 ◽  
Vol 581-582 ◽  
pp. 819-822 ◽  
Author(s):  
Bin Meng ◽  
Jin Hui Peng
Keyword(s):  
Fracture Toughness ◽  
Response Surface Methodology ◽  
Response Surface ◽  
Response Surface Method ◽  
Sintering Temperature ◽  
Surface Method ◽  
Mullite Whiskers ◽  
Optimized Conditions ◽  
Addition Amount

The corundum-mullite was toughened by in-situ synthesized mullite whiskers and the process parameters influencing the fracture toughness of corundum-mullite, such as sintering temperature, addition amount of AlF3 and V2O5, were optimized by means of response surface method. Corundum-mullite with fracture toughness of 9.44 MPa.m-1/2 could be obtained under the optimized conditions, i.e. sintering temperature of 1400°C, 4.8 wt.% of AlF3 and 5.8 wt.% of V2O5. The results showed that it was feasible to prepare corundum-mullite toughened by in-situ synthesized mullite whiskers by the optimized parameters. In addition, an accurate model based on response surface method was proposed to predict the experimental results.

In Situ Preparation and Mechanical Properties of (ZrB2+ZrC)/Zr3[Al(Si)]4C6 Composites

2014 ◽  
Vol 602-603 ◽  
pp. 438-442
Author(s):  
Lei Yu ◽  
Jian Yang ◽  
Tai Qiu
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Bending Strength ◽  
Coefficient Of Thermal Expansion ◽  
Raw Materials ◽  
Linear Increase ◽  
Fine Grain ◽  
Fine Grain Strengthening ◽  
Uniform Microstructure

Fully dense (ZrB2+ZrC)/Zr3[Al (Si)]4C6 composites with ZrB2 content varying from 0 to 15 vol.% and fixed ZrC content of 10 vol.% were successfully prepared by in situ hot-pressing in Ar atmosphere using ZrH2, Al, Si, C and B4C as raw materials. With the increase of ZrB2 content, both the bending strength and fracture toughness of the composites increase and then decrease. The synergistic action of ZrB2 and ZrC as reinforcements shows significant strengthening and toughing effect to the Zr3[Al (Si)]4C6 matrix. The composite with 10 vol.% ZrB2 shows the optimal mechanical properties: 516 MPa for bending strength and 6.52 MPa·m1/2 for fracture toughness. With the increase of ZrB2 content, the Vickers hardness of the composites shows a near-linear increase from 15.3 GPa to 16.7 GPa. The strengthening and toughening effect can be ascribed to the unique mechanical properties of ZrB2 and ZrC reinforcements, the differences in coefficient of thermal expansion and modulus between them and Zr3[Al (Si)]4C6 matrix, fine grain strengthening and uniform microstructure derived by the in situ synthesis reaction.

Mechanical properties of NiAl-Mo composites produced by specially controlled directional solidification

2012 ◽  
Vol 1516 ◽  
pp. 255-260 ◽  
Author(s):  
G. Zhang ◽  
L. Hu ◽  
W. Hu ◽  
G. Gottstein ◽  
S. Bogner ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Directional Solidification ◽  
Creep Resistance ◽  
Room Temperature ◽  
Growth Direction ◽  
Nominal Composition ◽  
Potential Candidate ◽  
In Situ Composites

ABSTRACTMo fiber reinforced NiAl in-situ composites with a nominal composition Ni-43.8Al-9.5Mo (at.%) were produced by specially controlled directional solidification (DS) using a laboratory-scale Bridgman furnace equipped with a liquid metal cooling (LMC) device. In these composites, single crystalline Mo fibers were precipitated out through eutectic reaction and aligned parallel to the growth direction of the ingot. Mechanical properties, i.e. the creep resistance at high temperatures (HT, between 900 °C and 1200 °C) and the fracture toughness at room temperature (RT) of in-situ NiAl-Mo composites, were characterized by tensile creep (along the growth direction) and flexure (four-point bending, vertical to the growth direction) tests, respectively. In the current study, a steady creep rate of 10-6s-1 at 1100 °C under an initial applied tensile stress of 150MPa was measured. The flexure tests sustained a fracture toughness of 14.5 MPa·m1/2at room temperature. Compared to binary NiAl and other NiAl alloys, these properties showed a remarkably improvement in creep resistance at HT and fracture toughness at RT that makes this composite a potential candidate material for structural application at the temperatures above 1000 °C. The mechanisms responsible for the improvement of the mechanical properties in NiAl-Mo in-situ composites were discussed based on the investigation results.

Effects of Hydrogen Partial Pressure on Hydrotreating of Heavy Gas Oil Derived from Oil-Sands Bitumen: Experimental and Kinetics

2010 ◽  
Vol 24 (2) ◽  
pp. 772-784 ◽  
Author(s):  
M. Mapiour ◽  
V. Sundaramurthy ◽  
A. K. Dalai ◽  
J. Adjaye
Keyword(s):  
Partial Pressure ◽  
Oil Sands ◽  
Hydrogen Partial Pressure ◽  
Gas Oil ◽  
Heavy Gas Oil ◽  
Heavy Gas ◽  
Oil Sands Bitumen

Characterization of YBa2Cu4O8 high temperature electrical properties and thermodynamic stability

1991 ◽  
Vol 6 (10) ◽  
pp. 2054-2058 ◽  
Author(s):  
B-S. Hong ◽  
T.O. Mason
Keyword(s):  
High Temperature ◽  
Electrical Property ◽  
Electrical Properties ◽  
Seebeck Coefficient ◽  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Pressure Range ◽  
Stability Range

Via in situ electrical property measurements (conductivity, Seebeck coefficient) over the temperature range 500–800 °C and oxygen partial pressure range 10−4-1 atm, the equilibrium transport properties and stability range of YBa2Cu4O8 were determined. YBa2Cu4O8 behaves like the intrinsically mixed-valent compound, magnetite (Fe3O4), with small variations in electrical properties with changes in oxygen partial pressure. The decomposition boundary to YBa2Cu3O6+y (or YBa2Cu3.5O7.5±z) and CuO occurs at log(po2, atm) = −1.24 × 104/T(K) + 11.01(773 ⋚ T(K) ⋚ 1073).

Low-Temperature Epitaxial Growth of IN-Situ HeavilY B-Doped Si1-xGex, Films Using Ultraclean LPCVD

1998 ◽  
Vol 533 ◽  
Author(s):  
A. Morrya ◽  
M. Sakuraba ◽  
T. Matsuura ◽  
J. Murota ◽  
I. Kawashima ◽  
...  
Keyword(s):  
Low Temperature ◽  
Partial Pressure ◽  
Epitaxial Growth ◽  
Lattice Constant ◽  
Deposition Rate ◽  
Epitaxial Films ◽  
Similar Degree ◽  
Gas Mixture ◽  
Heavy Doping

AbstractIn-situ heavy doping of B into Si1-xGex epitaxial films on the Si(100) substrate have been investigated at 550°C in a SiH4(6.0Pa)-GeH4(0.1−6.0Pa)-B2H6(1.25 ×10−5−3.75 × 10−2Pa)-H2(17–24Pa) gas mixture by using an ultraclean hot-wall low-pressure CVD system. The deposition rate increased with increasing GeH4 partial pressure, and it decreased with increasing B2H6 partial pressure only at the higher GeH4 partial pressure. As the B2H6 partial pressure increased, the Ge fraction scarcely changed although the lattice constant of the film decreased. These characteristics can be explained by the suppression of both the SiH4 and GeH4 adsorption/reactions in a similar degree due to B2H6 adsorption on the Si-Ge and/or Ge-Ge bond sites. The B concentration in the film increased proportionally up to 1022cm3 with increasing B2H6 partial pressure.

Self-Toughness Porous Sodium Titanate Bioceramics Prepared via In Situ Grown Na2Ti6O13 Rods

2017 ◽  
Vol 727 ◽  
pp. 806-814 ◽  
Author(s):  
Xiao Wei Ma ◽  
Jian Xing Shen ◽  
Ke Chang Zhang ◽  
Ling Kai Kong ◽  
Jia Le Sun ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Compressive Strength ◽  
Sodium Titanate ◽  
The Novel ◽  
Ceramic Samples ◽  
Porous Bioceramic ◽  
Different Temperatures ◽  
Growth Method ◽  
Titanate Ceramics

Here in, we report the porous bioceramic with Na2Ti6O13 rods prepared by in‒situ growth method. The samples were prepared using cold uniaxial pressing (40 MPa) technique and further sintered at different temperatures. The structure and morphology were characterized by XRD and SEM. The porosity, compressive strength and fracture toughness were also investigated. The bone-like apatite deposition ability of the fabricated ceramic samples was evaluated by Kokubo simulated body fluid (SBF) soaking method. The results indicated that the Na2Ti6O13 rods with about 1‒3 μm in diameter are uniformly distributed in the self‒toughness porous sodium titanate ceramics (SPSTC). The SPSTC with a porosity of 61.10±1.12 % exhibits good compressive strength (43.36±2.43 MPa) and fracture toughness (3.47±0.21 MPa·m1/2). The results indicate that the novel SPSTC scaffolds are promising for bone tissue engineering applications.

Sign in / Sign up

Export Citation Format

Share Document