scholarly journals Mechanical properties of ultra-high pressure sintered sphene (CaTiSiO5)

2016 ◽  
Vol 10 (4) ◽  
pp. 295-298
Author(s):  
Eranezhuth Awin ◽  
Branko Matovic ◽  
Jelena Maletaskic ◽  
Vladimir Urbanovich ◽  
Ravi Kumar
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
High Pressure ◽  
Elastic Modulus ◽  
High Pressures ◽  
Elastic Recovery ◽  
Maximum Load ◽  
Indentation Hardness ◽  
Ultra High Pressure ◽  
Indentation Crack

The investigation of nano-mechanical properties of sphene sintered under ultra-high pressures in the order of 4GPa is done using indentation techniques. An indentation hardness of 6.6GPa and reduced elastic modulus of 112.3GPa is reported at maximum load of 7mN. The material exhibits a high elastic recovery (~59.1%) and the nature of deformation mechanism has been comprehended from the plastic work ratio. In addition, the fracture toughness of the material is also evaluated using indentation crack length method.

Effect of High Pressure Heat Treatment on Microstructures and Micro-mechanical Properties of CuZn Alloy

2014 ◽  
Vol 33 (4) ◽  
pp. 339-344 ◽  
Author(s):  
Yuhui Wang ◽  
Jun Zhao ◽  
Jianhua Liu ◽  
Ruijun Zhang
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
High Pressure ◽  
Elastic Modulus ◽  
Friction Coefficient ◽  
Recovery Rate ◽  
Elastic Recovery ◽  
Modulus Ratio ◽  
Before And After ◽  
Cuzn Alloy

AbstractThe hardness, elastic modulus, and friction coefficient of the CuZn alloy before and after treatment at 700 °C and 3 GPa for 10 mins were measured by nanoindenter. Effects of high pressure heat treatment on its microstructure and micro-mechanical properties were discussed. The results show that high pressure heat treatment can refine the microstructures of the CuZn alloy, and its hardness, elastic modulus, ratio of hardness, and elastic recovery rate after the 3 GPa treatment increased by 15.44 %, 4.89 %, 8.82 % and 35.90 %, respectively. And the friction coefficient is also decreased.

Fabrication of Carbon Nanotube Reinforced Boron Carbide Composite by Hot-Pressing Following Extrusion Molding

2014 ◽  
Vol 616 ◽  
pp. 27-31 ◽  
Author(s):  
Tomohiro Kobayashi ◽  
Katsumi Yoshida ◽  
Toyohiko Yano
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Elastic Modulus ◽  
Carbon Nanotube ◽  
Boron Carbide ◽  
Vickers Hardness ◽  
Hot Pressing ◽  
Bending Strength ◽  
Extrusion Direction ◽  
Sem Observation

The CNT/B4C composite with Al2O3 additive was fabricated by hot-pressing following extrusion molding of a CNT/B4C paste, and mechanical properties of the obtained composite were investigated. Many CNTs in the composite aligned along the extrusion direction from SEM observation. 3-points bending strength of the composite was slightly lower than that of the monolithic B4C. Elastic modulus and Vickers hardness of the composite drastically decreased with CNT addition. Fracture toughness of the composite was higher than that of the monolithic B4C.

scholarly journals Effect of growth conditions on the mechanical properties of lanthanum-gallium tantalate crystals

2020 ◽  
Vol 6 (2) ◽  
pp. 65-70
Author(s):  
Mark V. Weintraub ◽  
Nina S. Kozlova ◽  
Evgeniya V. Zabelina ◽  
Mikhail I. Petrzhik
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Elastic Recovery ◽  
Growth Conditions ◽  
Piezoelectric Response ◽  
Instrumented Indentation ◽  
Recovery Coefficient ◽  
Hardness Tester ◽  
Growth Atmosphere ◽  
Oxygen Addition

The effect of growth conditions, anisotropy and polarity of specimens on the mechanical properties of lanthanum-gallium tantalate La3Ta0.5Ga5.5O14 single crystals grown in different atmospheres (argon (Ar), argon with oxygen addition (Ar+(<2%)O2 and Ar+(2%)O2) and air) was studied. The test specimens for the measurements were cut perpendicularly to a 3rd order axis (Z cuts) and in polar directions perpendicular to a 2nd order axis (Y cuts). The polarity of the Y cut specimens was tested by piezoelectric response. The brittleness was evaluated by microindentation at 3, 5, 10 and 25 g loads. The brittleness proved to show itself at a 5 g and the higher loads regardless of growth atmosphere. Therefore microhardness tests were done at loads of within 3 g. The microhardness HV of the specimens was measured with an DM 8B Affri microhardness tester by Vickers methods. The hardness H, elastic modulus E and elastic recovery coefficient R were measured with a Berkovich pyramid on a CSM Nano-Hardness Tester using the instrumented indentation (nanoindentation) method. Growth atmosphere was shown to affect the mechanical properties of lanthanum-gallium tantalate crystals: crystals grown in an oxygen-free argon atmosphere had the lowest microhardness, hardness, elastic modulus and elastic recovery coefficient. The lowest microhardness was detected in Z cut specimens regardless of growth atmosphere. The mechanical properties of polar Y cuts proved to be anisotropic: the microhardness, hardness, elastic modulus and elastic recovery coefficient of these cuts were lower for positive cuts than for negative ones regardless of growth atmosphere. Y and Z cut langatate specimens grown in argon with less than two percent oxygen exhibited strong elastic modulus and elastic recovery coefficient anisotropy.

Mechanical Behavior of the Cr3C2 Compound at High Pressure and High Temperature

2015 ◽  
Vol 1120-1121 ◽  
pp. 1187-1193 ◽  
Author(s):  
Bin Li Jiang ◽  
Zi Li Kou ◽  
De Jiang Ma ◽  
Yong Kun Wang ◽  
Chun Xia Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
High Pressure ◽  
Relative Density ◽  
X Ray Diffraction ◽  
Density Measurements ◽  
X Ray ◽  
Hardness Tests ◽  
Novel Method ◽  
Heat Preservation

In the present study, we present a novel method to sinter Cr3C2 powders under high pressure without any addittives. The sintering Cr3C2 samples were charaterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), relative density measurements, Vicker’s hardness tests and Fracture toughness tests. The reasults show that Cr3C2 powders could be sintered to be bulk under the conditions of 3-5 GPa, 800-1200 °C and the heat preservation for 15 min. Moreover, the sintering body of Cr3C2 compound with the relative density of 99.84% by simultaneously tuning the pressure-temperature conditions exhibited excellent mechanical properties: a Vickers hardness of 20.3 GPa and a fracture toughness of ~8.9 MPam1/2. These properties were much higher than that by using the previous methods. The temperature condition obtained good mechanical properties in the experiment was about 1/3 lower than that using any other methods owing to the high pressure.

Fracture Toughness and Adhesion Energy of Sol-gel Coatings on Glass

2002 ◽  
Vol 17 (1) ◽  
pp. 224-233 ◽  
Author(s):  
Jaap Den Toonder ◽  
Jürgen Malzbender ◽  
Gijsbertus De With ◽  
Ruud Balkenende
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Elastic Modulus ◽  
Sol Gel ◽  
Industrial Applications ◽  
Adhesion Energy ◽  
Scratch Testing ◽  
New Methods ◽  
Quantitative Results ◽  
Coating Fracture

The reliability of coatings that are used in industrial applications critically depends on their mechanical properties. Nanoindentation and scratch testing are well-established techniques to measure some of these properties, namely the elastic modulus and hardness of coatings. In this paper, we investigate the possibility of also assessing the coating fracture toughness and the energy of adhesion between the coating and the substrate using indentation and scratch testing. Various existing and new methods are discussed, and they are illustrated by measurements on particle-filled sol-gel coatings on glass. All methods are based on the occurrence of cracking, and they are therefore only applicable to coating systems that act like brittle materials and exhibit cracking during indentation and scratching. The methods for determining the fracture toughness give comparable results, but the values still differ to within about 50%. The values of the adhesion energy obtained from different measurements are consistent, but it remains uncertain to which extent the obtained values are quantitatively correct. The results show that the methods used are promising, but more research is needed to obtain reliable quantitative results.

Length Scale Effects in Materials Deformation of Nano and Microscale Au Structures

2009 ◽  
Author(s):  
Jie Lian ◽  
Junlan Wang
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Size Effect ◽  
Sample Size ◽  
Atomistic Simulation ◽  
Scale Effects ◽  
Elastic Recovery ◽  
Boundary Effect ◽  
Dislocation Nucleation ◽  
Atomistic Simulations

In this study, intrinsic size effect — strong size dependence of mechanical properties — in materials deformation was investigated by performing atomistic simulation of compression on Au (114) pyramids. Sample boundary effect — inaccurate measurement of mechanical properties when sample size is comparable to the indent size — in nanoindentation was also investigated by performing experiments and atomistic simulations of nanoindentation into nano- and micro-scale Au pillars and bulk Au (001) surfaces. For intrinsic size effect, dislocation nucleation and motions that contribute to size effect were analyzed for studying the materials deformation mechanisms. For sample boundary effect, in both experiments and atomistic simulation, the elastic modulus decreases with increasing indent size over sample size ratio. Significantly different dislocation motions contribute to the lower value of the elastic modulus measured in the pillar indentation. The presence of the free surface would allow the dislocations to annihilate, causing a higher elastic recovery during the unloading of pillar indentation.

scholarly journals Ultra High Pressure Liquid Chromatography for Crude Plant Extract Profiling

2011 ◽  
Vol 94 (1) ◽  
pp. 51-70 ◽  
Author(s):  
Philippe J Eugster ◽  
Davy Guillarme ◽  
Serge Rudaz ◽  
Jean-Luc Veuthey ◽  
Pierre-Alain Carrupt ◽  
...  
Keyword(s):  
High Pressure ◽  
Liquid Chromatography ◽  
High Pressure Liquid Chromatography ◽  
High Pressures ◽  
Product Analysis ◽  
Basic Principles ◽  
Ultra High Pressure ◽  
Crude Plant Extract ◽  
Phase Chemistry ◽  
Very High

Abstract Ultra high pressure liquid chromatography (UHPLC) systems operating at very high pressures and using sub-2 μm packing columns have allowed a remarkable decrease in analysis time and increase in peak capacity, sensitivity, and reproducibility compared to conventional HPLC. This technology has rapidly been widely accepted by the analytical community and is being gradually applied to various fields of plant analysis such as QC, profiling and fingerprinting, dereplication, and metabolomics. For many applications, an important improvement of the overall performances has been reported. In this review, the basic principles of UHPLC are summarized, and practical information on the type of columns used and phase chemistry available is provided. An overview of the latest applications to natural product analysis in complex mixtures is given, and the potential and limitations as well as some new trends in the development of UHPLC are discussed.

A Method to Determine Fracture Toughness Using Berkovich Indenter for Bulk Materials

2013 ◽  
Vol 331 ◽  
pp. 456-460
Author(s):  
Min He ◽  
Duan Hu Shi ◽  
Feng Yang ◽  
Ning Zhang ◽  
Hua Feng Guo
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Elastic Modulus ◽  
Penetration Depth ◽  
Effective Elastic Modulus ◽  
Berkovich Indenter ◽  
Bulk Materials ◽  
Ductile Materials ◽  
Penetration Depths ◽  
Determine Fracture Toughness

An indentation approach with Berkovich indenter is proposed to determine fracture toughness for ductile materials. With decrease of effective elastic modulus, an approximate linear relationship between logarithmic plastic penetration depth and logarithmic effective elastic modulus, and a quadratic polynomial relationship between the plastic penetration depths and penetration loads are exhibited by indentation investigation with Berkovich indenter. The damage constructive equation of effective elastic modulus is proposed to determine the critical effective elastic modulus at the fracture point, which is the key problem to calculate the indentation energy to fracture. The critical plastic penetration depth is identified after the critical effective elastic modulus can be predicted by conventional mechanical properties. The fracture toughness is calculated according to the equation of penetration load, plastic penetration depth and the critical plastic penetration depth.

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