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.

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 FeZrN Films: Magnetic and Mechanical Properties Relative to the Phase-Structural State

Materials ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 137
Author(s):  
Elena N. Sheftel ◽  
Valentin A. Tedzhetov ◽  
Eugene V. Harin ◽  
Philipp V. Kiryukhantsev-Korneev ◽  
Galina S. Usmanova ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Magnetic Properties ◽  
Elastic Modulus ◽  
Elastic Recovery ◽  
The Other ◽  
Magnetron Deposition ◽  
Glass Substrates ◽  
Saturation Induction ◽  
Low Elastic Modulus ◽  
Chemical And Phase Compositions

The paper presents results of investigation of Fe65.3–100Zr34.7–0N7.5–0 films prepared by dc magnetron deposition on glass substrates and subsequent 1-hour annealing at temperatures of 300–600 °C. The influence of the chemical and phase compositions and structure of the films, which were studied by TEM, SEM, XRD, and GDOES, on their mechanical properties determined by nanoindentation and static magnetic properties measured by VSM method is analyzed. The studied films exhibit the hardness within a range of 14–21 GPa, low elastic modulus (the value can reach 156 Gpa), and an elastic recovery of 55–83%. It was shown that the films are strong ferromagnets with the high saturation induction Bs (up to 2.1 T) and low coercive field Hc (as low as 40 A/m). The correlations between the magnetic and mechanical properties, on one hand, and the chemical composition of the films, their phase, and structural states as well, on the other hand, are discussed.

Estimating Energy Dissipation of Ceramics via H-E Ratio

2010 ◽  
Vol 434-435 ◽  
pp. 205-208
Author(s):  
Yi Wang Bao ◽  
De Tian Wan ◽  
Yan Qiu
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Energy Dissipation ◽  
Elastic Recovery ◽  
Engineering Application ◽  
Basic Data ◽  
Recovery Resistance ◽  
Reduced Modulus ◽  
Energy Dissipation Capacity

Mechanical properties of ceramics are important for its engineering application. It would be significant and efficient if some properties could be estimated without tests. Energy dissipation capacity of ceramics is estimated in this work via two common parameters, hardness and elastic modulus, which could be obtained from basic data of commercial ceramics or simple tests. The ratio of hardness to reduced modulus H/Er is found to be related to recovery resistance and energy dissipation capacity of the materials, and the related equations were induced. The reduced modulus can be expressed by conventional elastic modulus E. Thus, the capacity of energy dissipation and elastic recovery can be estimated simply from the H/E ratio. The calculated results indicate that the value of H/E ratio is in reverse proportion to the energy dissipation. Several ceramics with different H/E ratio are analyzed and their energy dissipation capacities are estimated.

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.

Ti-Based Nanostructure Coating on Mg Alloys

2007 ◽  
Vol 334-335 ◽  
pp. 269-272
Author(s):  
Y.L. Chiu ◽  
V. So ◽  
Zheng Wei Li
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Mg Alloys ◽  
Maximum Hardness ◽  
Dc Magnetron Sputtering ◽  
Aluminium Concentration ◽  
Strain Burst ◽  
Hardness Tester ◽  
Fine Structures ◽  
Hardness Values

In this work, we report our study of the microstructure and mechanical properties of pure Ti, Ti-11Al, Ti-47Al and Ti-6Al-4V nanostructure coatings on AZ91D Mg alloys prepared using DC magnetron sputtering. The fine structures of the coating (see fig. 1 for Ti-6Al-4V coating) are presented. The hardness of the coatings were tested on a CSEM nano-hardness tester with a Berkovich diamond intender. Hardness values were obtained from analyses using the Oliver-Pharr scheme. The hardness of the nanostructure coating increases from about 3.5GPa up to about 6.8GPa when the aluminium concentration increases from zero to 47at.%. Maximum hardness value was found on the Ti-6Al-4V coating, about 7.3GPa. The elastic modulus of the pure Ti coating has the lowest modulus and strain burst “pop-in” has been observed on Ti-47Al coating.

Study on Physio-Mechanical Properties of Rice Husk Ash Polyester Resin Composite

2015 ◽  
Vol 53 ◽  
pp. 95-105 ◽  
Author(s):  
Md Mahfujul Islam ◽  
Humayun Kabir ◽  
Md Abdul Gafur ◽  
Md. Mahbubur Rahman Bhuiyan ◽  
Md Alamgir Kabir ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Rice Husk ◽  
Polyester Resin ◽  
Rice Husk Ash ◽  
Resin Composite ◽  
Testing Machine ◽  
Ash Content ◽  
Flexure Strength ◽  
Hardness Tester

The rice husk ash/polyester resin composites were prepared by compression molding method and their physical and mechanical properties were studied by universal testing machine. The hardness of the composites were tested by Leeb rebound hardness tester and Vickers hardness tester .The bulk density of the rice husk ash/polyester resin composite decreased with the addition of the rice husk ash, and the water absorption also found to be increased with increase in soaking time. Flexure strength of the composite was decreased randomly with an increase in rice husk ash content. The elastic modulus for the flexure strength increased up to the percentage 0-10% but decreased on 15% and 20% of the rice husk ash/polyester composite. The compressive strength of the composites was decreased randomly with the addition of rice husk ash content, and the elastic modulus for compressive test was increased firstly on the addition of rice husk ash, but it was decreased after 5%. The Hardness of the prepared composite was found to be decreased with an increase of the addition of rice husk ash content due to elastic deformation.

Evaluation of Fracture Toughness of Structural Ceramic by Instrumented Indentation

2013 ◽  
Vol 312 ◽  
pp. 575-578
Author(s):  
Zhong Kang Song ◽  
De Jun Ma ◽  
Wei Chen ◽  
Jun Hong Guo
Keyword(s):  
Fracture Toughness ◽  
Elastic Modulus ◽  
Zirconium Oxide ◽  
Traditional Method ◽  
Sample Surface ◽  
Ceramic Materials ◽  
Instrumented Indentation ◽  
Structural Ceramic ◽  
Surface Fracture ◽  
Hardness Tester

Fracture toughness of structural ceramic materials can be obtained with one instrumented macro-indentation tester with a Vickers indenter, which is superior to the traditional method which first uses a nanoindentation tester or other instruments to get elastic modulus and then use a large load hardness tester to make crack on the sample surface. Fracture toughness of two ceramic materials: silicon nitride and zirconium oxide is tested on the instrumented macro-indentation tester. The results are 5.93 ~7.05MPam1/2and 7.68~8.57 MPam1/2.

Structural Phase State and Mechanical Properties of the Si-Al-N Coatings with Different Concentration Ratio of Al and Si

2015 ◽  
Vol 1085 ◽  
pp. 289-293 ◽  
Author(s):  
Viktor Sergeev ◽  
Marina V. Fedorischeva ◽  
Mark P. Kalashnikov ◽  
Irina A. Bozhko ◽  
Andrey V. Voronov ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Concentration Ratio ◽  
Phase State ◽  
Elastic Recovery ◽  
Structural Phase ◽  
Nanocomposite Coatings ◽  
Reactive Magnetron ◽  
Recovery Coefficient ◽  
Structural Phase State ◽  
X Ray

The amorphous and nanocomposite coatings on the basis of Si-Al-N with different ratios of Al and Si concentrations were prepared by reactive magnetron sputtering method. Structural-phase state of coatings on the basis of Si-Al-N was investigated by TEM, SEM and X-ray analysis. Microhardness, modulus of elasticity, elastic recovery coefficient was determined by nanoindentation method.

Local Mechanical Properties of Cast and Sintered High Cr-Alloyed Steel

2013 ◽  
Vol 586 ◽  
pp. 241-244
Author(s):  
Ruslan Shvab ◽  
Pavol Hvizdoš ◽  
Eva Dudrová ◽  
Ola Bergman ◽  
Sven Bengtsson
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Chemical Composition ◽  
Sintered Material ◽  
Indentation Hardness ◽  
Instrumented Indentation ◽  
Indentation Method ◽  
Load Range ◽  
Cast Steels ◽  
Load Size

Local mechanical properties of high Cr-alloyed sintered and cast steels with the same chemical composition were investigated using instrumented indentation method. Standard loading/unloading mode was applied, the measurements were done in load range 1 – 500 mN. Load size effect was observed and its parameters were evaluated. Indentation hardness and elastic modulus were found slightly higher for the sintered material. Differences in indentation parameters were explained based on microstructure of materials.

EFFECT OF FILTER COIL CURRENT ON PROPERTIES OF nc-TiC/a-C:H NANOCOMPOSITE FILM PREPARED BY DUAL PLASMA TECHNIQUE

2007 ◽  
Vol 14 (06) ◽  
pp. 1143-1148 ◽  
Author(s):  
YAOHUI WANG ◽  
XU ZHANG ◽  
XIANYING WU ◽  
HUIXING ZHANG ◽  
XIAOJI ZHANG
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Structural Properties ◽  
Deposition Rate ◽  
Nanocomposite Film ◽  
Elastic Recovery ◽  
Coil Current ◽  
Plasma Technique ◽  
High Elastic Modulus ◽  
Unusual Combination

Nanocomposite nc-TiC / a-C : H films, with an unusual combination of superhardness and high elastic recovery, are prepared by using dual plasma technique. The effect of the filter coil current on the compositional and structural properties of the nc-TiC / a-C : H films has been investigated. It is found that the deposition rate and the composition of nc-TiC / a-C : H films could be changed by varying the filter coil current. Fortunately, by selecting the proper value of the filter coil current, 2.5 A, one can remarkably enhance the mechanical properties of the film, such as the superhardness (66.4 GPa), the high elastic modulus (510 GPa), and the high elastic recovery (83.3%).

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