Indentation Induced Deformation and Crack Behavior of β-SiC Irradiated at High Temperature

2005 ◽  
Vol 287 ◽  
pp. 489-494
Author(s):  
Kyeon Hwan Park ◽  
Tatsuya Hinoki ◽  
Akira Kohyama
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Physical And Mechanical Properties ◽  
Radiation Hardening ◽  
Irradiation Damage ◽  
Indentation Method ◽  
Microstructural Observation ◽  
Crack Behavior ◽  
Complex Propagation ◽  
Property Changes

Irradiation damage produced by neutrons or energetic particles lead to changes of physical- and mechanical-properties of SiC. Radiation hardening and fracture toughness changing of SiC were clarified by indentation method previously. However, the mechanism studies have received little alteration. The purpose of this study is to improve the understanding of the mechanisms of mechanical property changes under irradiation. In this paper, the microstructural observation beneath and near an indentation will be used to infer mechanisms of radiation hardening and toughening. Indenting polycrystalline SiC creates deformation and cracking in the plastically deformed region. In the case of irradiated SiC, however, small-sized deformation zone was observed below contact indent, which resulted in the restricted size of residual impression. Additionally, the indentation cracks showed complex propagation behaviors such as deflecting, branching and microcracking.

Influence of 6PPD Stabilizer on Climatic Stability of Rubbers Based on Butadiene-Nitrile and Epichlorohydrin Rubbers

2019 ◽  
Vol 945 ◽  
pp. 433-437
Author(s):  
M.D. Sokolova ◽  
A.F. Fedorova ◽  
M.L. Davydova
Keyword(s):  
Mechanical Properties ◽  
Physical And Mechanical Properties ◽  
Hydraulic Fluids ◽  
Open Ground ◽  
The Republic ◽  
The Stability ◽  
Property Changes ◽  
Full Scale Tests ◽  
Butadiene Nitrile Rubber ◽  
Hydrocarbon Media

The present paper outlines the results of full-scale tests of climatic stability and the study of resistance to the action of hydrocarbon media of rubbers based on BNKS-18-18 (butadiene-nitrile rubber) and Hydrin T6000 epichlorohydrin rubber containing one of 6PPDstabilizerwith an aromatic amine moiety widely used in synthetic rubbers. Samples are exposed in an open ground under natural conditions of exposure to climatic external factors of Yakutsk in the Republic of Sakha (Yakutia), as well as in the oil environment of Talakanskoye field and I-50A hydraulic fluid in an unheated room. Such indexes of the samples as conditional tensile strength, elongation at rupture, hardness and degree of swelling are measured to determine the resistance of rubbers to aging after the first, third, and sixth months of exposing. The results of the study reveal the contribution of 6PPD stabilizer in maintaining the stability of the physical and mechanical properties of BNKS-18: rubber containing 6PPD has less property changes both in the open air and in hydrocarbon media compared to rubber without a stabilizer. It should be noted that the oil environment is the most aggressive environment, the swelling of rubbers in oil leads to a significant reduction in strength due to a decrease in intermolecular interaction.6PPD stabilizer occurred less effective for the rubber based on Hydrin T6000: changes in properties of the samples containing the stabilizer are larger than those of the samples without the stabilizer. However, unlike BNKS-18-18-based rubber, the swelling of rubber based on Hydrin T6000 led to the greatest stability of the physical and mechanical properties in the oil environment compared to the open air and hydraulic fluids.

Effect of MgO Nano Particle on Mechanical Property and Microstructure of ZTA Ceramic Composite

2011 ◽  
Vol 364 ◽  
pp. 450-454 ◽  
Author(s):  
Ahmad Zahirani Ahmad Azhar ◽  
Mohamad Hasmaliza ◽  
Manimaran Ratnam ◽  
Zainal Arifin Ahmad
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Vickers Hardness ◽  
Ceramic Composite ◽  
Weight Percent ◽  
Alumina Ceramic ◽  
Nano Particle ◽  
Microstructural Observation ◽  
Hardness Property ◽  
Zirconia Toughened Alumina

The mechanical properties and microstructure of zirconia-toughened-alumina ceramic composite doped with nanoparticle of MgO is investigated. The nanoMgO weight percent was varied from 0.3 wt % to 1.3 wt %. Each batch of composition was mixed using ultrasonic cleaner and mechanical stirrer, uniaxially pressed and sintered at 1600 °C for 4 h in pressureless conditions. Analysis of bulk density, Vickers hardness and microstructural observation has been carried out. Results of Vickers hardness increased linearly with addition of more nanoMgO until a certain composition. Maximum Vickers hardness obtained was 1740HV with 1.1 wt % MgO. Furthermore, microstructural observations show that the Al2O3 grain size depends on the particle size of MgO, and is directly related to its hardness property.

scholarly journals Mechanical Property Changes in Breast Cancer Cells Induced by Stimulation with Macrophage Secretions in Vitro

Micromachines ◽  
2019 ◽  
Vol 10 (11) ◽  
pp. 738 ◽  
Author(s):  
Hyonchol Kim ◽  
Kenta Ishibashi ◽  
Tomoko Okada ◽  
Chikashi Nakamura
Keyword(s):  
Breast Cancer ◽  
Mechanical Properties ◽  
Mechanical Property ◽  
Cancer Cells ◽  
Cancer Cell ◽  
Breast Cancer Cells ◽  
Tumor Microenvironments ◽  
Before And After ◽  
Property Changes

The contribution of secretions from tumor-associated macrophage (TAM)-like cells to the stimulation of mechanical property changes in murine breast cancer cells was studied using an in vitro model system. A murine breast cancer cell line (FP10SC2) was stimulated by adding macrophage (J774.2) cultivation medium containing stimulation molecules secreted from the macrophages, and changes in mechanical properties were compared before and after stimulation. As a result, cell elasticity decreased, degradation ability of the extracellular matrix increased, and the expression of plakoglobin was upregulated. These results indicate that cancer cell malignancy is upregulated by this stimulation. Moreover, changes in intercellular adhesion strengths between pairs of cancer cells were measured before and after stimulation using atomic force microscopy (AFM). The maximum force required to separate cells was increased by stimulation with the secreted factors. These results indicate the possibility that TAMs cause changes in the mechanical properties of cancer cells in tumor microenvironments, and in vitro measurements of mechanical property changes in cancer cells will be useful to study interactions between cells in tumor microenvironments.

An Experimental Investigation on Mechanical Properties and Microstructure of Friction Stir Welding of AA5052

2014 ◽  
Vol 592-594 ◽  
pp. 48-52 ◽  
Author(s):  
C. Chanakyan ◽  
P. Dinesh Babu ◽  
M.P. Jenarthanan ◽  
K. Jagathesh
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Friction Stir Welding ◽  
Traverse Speed ◽  
Special Focus ◽  
Nugget Zone ◽  
Friction Stir ◽  
Before And After ◽  
Property Changes ◽  
Tool Pin

The aim of this project is to study the micro-structural and mechanical property changes during friction stir welding [FSW] with a special focus on AA5052. The objective of this project is to experimentally investigate the influence of tool pin profiles (straight cylinder, fluted cylinder and pentagonal cylinders) and welding input parameters (rotational speed and traverse speed) on microstructure and mechanical properties (tensile strength, hardness) of AA5052 Al in FSW process. The detailed micro-structural analyses are carried out on the base metal and welded zone (nugget zone), Thermo mechanically affected zone and heat affected zone. The mechanical properties such as, tensile and hardness are studied before and after FSW process.

Study on Modification of the Magnesium Phosphate Cement-Based Material by Fly Ash

2010 ◽  
Vol 150-151 ◽  
pp. 1655-1661 ◽  
Author(s):  
Dong Xu Li ◽  
Chun Hua Feng
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Fly Ash ◽  
Chemical Reactions ◽  
Setting Time ◽  
Physical And Mechanical Properties ◽  
Magnesium Phosphate ◽  
Excellent Mechanical Property

Fly ash can improve the physical and mechanical properties of the magnesium phosphate cement (MPC) paste. The influence of fly ash on the strength, the mortar fluidity, the durability and the setting time of MPC paste were studied in this paper. The results show that: The function of fly ash to the MPC is as followed: physical fill, superplastic and chemical reactions; the optimal content of fly ash is about 30% by weight, and MPC with 30% fly ash has excellent mechanical property and high fluidity; the fineness of magnesia affected the mechanical properties of MPC.

scholarly journals Investigating longitudinal changes in the mechanical properties of MCF-7 cells exposed to paclitaxol using particle tracking microrheology

2021 ◽  
Author(s):  
Michael C. Kolios
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Shear Modulus ◽  
Shear Wave ◽  
Particle Tracking ◽  
Drug Exposure ◽  
Shear Wave Elastography ◽  
Particle Tracking Microrheology ◽  
Property Changes ◽  
Mcf 7

Evidence suggests that compression and shear wave elastography are sensitive to the mechanical property changes occuring in dying cells following chemotherapy, and can hence be used to monitor cancer treatment response. A qualitative and quantitative understanding of the mechanical changes at the cellular level would allow to better infer how these changes affect macroscopic tissue mechanical properties and therefore allow the optimization of elastographic techniques (such as shear wave elastography) for the monitoring of cancer therapy. We used intracellular particle tracking microrheology (PTM) to investigate the mechanical property changes of cells exposed to paclitaxol, a mitotic inhibitor used in cancer chemotherapy. The average elastic and viscous moduli of the cytoplasm of treated MCF-7 breast cancer cells were calculated for frequency ranges between 0.2 and 100 rad s–1 (corresponding to 0.03 and 15.92 Hz, respectively). A significant increase in the complex shear modulus of the cell cytoplasm was detected at 12 h post treatment. At 24 h after drug exposure, the elastic and viscous moduli increased by a total of 191.3 Pa (>8000×) and 9 Pa (~9×), respectively for low frequency shear modulus measurements (at 1 rad s–1). At higher frequencies (10 rad s–1), the elastic and viscous moduli increased by 188.5 Pa (~60×) and 1.7 Pa (~1.1×), respectively. Our work demonstrates that PTM can be used to measure changes in the mechanical properties of treated cells and that cell elasticity significantly increases by 24 h after chemotherapy exposure.

scholarly journals Grain Size Dependent Mechanical Properties in Nanophase Materials

1994 ◽  
Vol 362 ◽  
Author(s):  
Richard W. Siegel ◽  
Gretchen E. Fougere
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Grain Size ◽  
Grain Boundary ◽  
Present Knowledge ◽  
New Materials ◽  
Size Dependent ◽  
Grain Structures ◽  
Nanophase Materials ◽  
Property Changes

AbstractIt has become possible in recent years to synthesize metals and ceramics under well controlled conditions with constituent grain structures on a nanometer size scale (below 100 nm). These new materials have mechanical properties that are strongly grain-size dependent and often significantly different than those of their coarser grained counterparts. Nanophase metals tend to become stronger and ceramics are more easily deformed as grain size is reduced. The observed mechanical property changes appear to be related primarily to grain size limitations and the large percentage of atoms in grain boundary environments. A brief overview of our present knowledge about the grain-size dependent mechanical properties of nanophase materials is presented.

scholarly journals Investigating longitudinal changes in the mechanical properties of MCF-7 cells exposed to paclitaxol using particle tracking microrheology

2021 ◽  
Author(s):  
Michael C. Kolios
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Shear Modulus ◽  
Shear Wave ◽  
Particle Tracking ◽  
Drug Exposure ◽  
Shear Wave Elastography ◽  
Particle Tracking Microrheology ◽  
Property Changes ◽  
Mcf 7

Evidence suggests that compression and shear wave elastography are sensitive to the mechanical property changes occuring in dying cells following chemotherapy, and can hence be used to monitor cancer treatment response. A qualitative and quantitative understanding of the mechanical changes at the cellular level would allow to better infer how these changes affect macroscopic tissue mechanical properties and therefore allow the optimization of elastographic techniques (such as shear wave elastography) for the monitoring of cancer therapy. We used intracellular particle tracking microrheology (PTM) to investigate the mechanical property changes of cells exposed to paclitaxol, a mitotic inhibitor used in cancer chemotherapy. The average elastic and viscous moduli of the cytoplasm of treated MCF-7 breast cancer cells were calculated for frequency ranges between 0.2 and 100 rad s–1 (corresponding to 0.03 and 15.92 Hz, respectively). A significant increase in the complex shear modulus of the cell cytoplasm was detected at 12 h post treatment. At 24 h after drug exposure, the elastic and viscous moduli increased by a total of 191.3 Pa (>8000×) and 9 Pa (~9×), respectively for low frequency shear modulus measurements (at 1 rad s–1). At higher frequencies (10 rad s–1), the elastic and viscous moduli increased by 188.5 Pa (~60×) and 1.7 Pa (~1.1×), respectively. Our work demonstrates that PTM can be used to measure changes in the mechanical properties of treated cells and that cell elasticity significantly increases by 24 h after chemotherapy exposure.

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