scholarly journals Nanomechanical and Macrotribological Properties of CVD-Grown Graphene as a Middle Layer between Metal Pt Cylinders and SiO2/Si Substrate

2015 ◽  
Vol 2015 ◽  
pp. 1-7
Author(s):  
Hongyan Wu ◽  
Zhengbin Gu ◽  
Shantao Zhang ◽  
G. Hussain
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Friction Coefficient ◽  
Magnetron Sputtering ◽  
Microelectromechanical Systems ◽  
Middle Layer ◽  
Si Substrate ◽  
Wear Performance ◽  
Periodic Arrays ◽  
Grown Graphene

The CVD-grown graphene as a middle layer was introduced between Pt cylinders and SiO2/Si to extend the application of graphene for improving the wear performance of microelectromechanical systems. Periodic arrays of Pt cylinders were prepared on the graphene/SiO2/Si (Pt/graphene) and SiO2/Si substrate (Pt/SiO2) using the magnetron sputtering technique. To characterize Pt/graphene and Pt/SiO2, nanoindentation and macrotribological tests were performed. The results showed that the friction coefficient was lower and the wear lifetime of Pt/graphene was longer than those of Pt/SiO2. Graphene, as a middle layer, was not only observed to have significant influence on the mechanical properties (i.e., microhardness and elastic modulus), but also found to improve the adhesive strength between SiO2/Si and Pt cylinders.

Analysis of Mechanophysical Properties of Fritillaria ussuriensis Maxim and Designing of Grade Sieve Machine

2013 ◽  
Vol 764 ◽  
pp. 165-168
Author(s):  
Jiang Song ◽  
Song Zhuo Lu ◽  
Li Hua Liu ◽  
Ming Wang ◽  
Tian Xiang Liu
Keyword(s):  
Mechanical Properties ◽  
Friction Coefficient ◽  
Physical And Mechanical Properties ◽  
Middle Layer ◽  
Mathematical Statistics ◽  
Angle Of Repose ◽  
Screening Process ◽  
Geometrical Properties ◽  
Pore Dimension ◽  
Main Index

Based on the field and lab measuerement in harvest time, Physical and mechanical properties of fritillaria ussuriensis maxim (FUM) are researched. Geometrical properties of FUM are analyzed using mathematical statistics method, and the variation sections of main index values of two kinds of FUM are obtained. Mechanical properties of FUM outsifting in screen penetrating process are tested by means of friction experiment, the friction coefficient and angle of repose of two kinds of FUM are obtained using mathematical statistics method. Grade sieve machine is designed based on the analysis of mechanophysical properties of FUM. The main parameters are: shape of sieve pore is rectangle, screen diameter is 20mm, sieve pore dimension of upper layer is 13×20mm2, middle layer is 9×18mm2, and under layer is 7×10mm2. By testing of friction coefficient and angle of repose and movement and dynamics analysis of grade sieve, outsifting velocity is 7<<9rad/s and acceleration is 4<a<13m/s2 in screening process.

scholarly journals Magnetron Sputtering Construction of Nano-Al Metallized Wood and Its Functional Research

Forests ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1564
Author(s):  
Yanan Wang ◽  
Chengzhu Jin ◽  
Xinyi Wang ◽  
Qiushuang Li ◽  
Wenxuan Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Magnetron Sputtering ◽  
Sheet Resistance ◽  
Wood Surface ◽  
Functional Improvement ◽  
Material Structure ◽  
Wetting Properties ◽  
Al Metallization ◽  
Wood Surfaces

The magnetron sputtering method was used to deposit nano-Al film on the wood surface of Pinus sylvestris L. var. mongholica Litv., and the material structure, electrical conductivity, mechanical properties and wetting properties were tested and characterized. When the sputtering time was 60 min, the average cross-grain sheet resistance of metallized wood was 695.9 mΩ, and the average along-grain sheet resistance was 227.2 mΩ. Load displacement decreased by more than 88%,elastic modulus increased by 49.2 times, hardness increased by 46 times andsurface hydrophobic angle was close to 130°. The grain size of the Al film on the wood surface was presented as nanoparticles, and the arrangement was uniform and dense. The results indicate that without any burden on the environment, the use of magnetron sputtering can quickly and efficiently achieve Al metallization on wood surfaces, so that the wood surface can obtain conductivity and hydrophobic properties. The elastic modulus and hardness of the wood surface were improved, the mechanical properties of the wood were effectively improved and the functional improvement of the wood was realized. This study provides a feasible method and basis for the study of the simple, efficient and pollution-free modification of wood.

Experimental Investigation into the Influences of Weathering on the Mechanical Properties of Sedimentary Rocks

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Xiaoshuang Li ◽  
Yingchun Li ◽  
Saisai Wu
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Elastic Modulus ◽  
Friction Coefficient ◽  
Uniaxial Compression ◽  
Sedimentary Rocks ◽  
Uniaxial Tensile ◽  
Mechanical Parameters ◽  
Uniaxial Tensile Strength ◽  
Weathering Grades

The time-dependent behaviors of the sedimentary rocks which refer to the altering of the mechanical and deformable properties of rock elements in the long-term period are of increasing importance in the investigation of the failure mechanism of the rock strata in underground coal mines. In order to obtain the accurate and reliable mechanical parameters of the sedimentary rocks at different weathering grades, the extensive experimental programs including the Brazilian splitting test, uniaxial compression tests, and direct shear tests have been carried out on the specimens that exposed to the nature environments at different durations. The correlation between the weathering grades and mechanical parameters including uniaxial tensile strength, uniaxial compression strength, elastic modulus, Poisson’s ratio, cohesion, and friction coefficient was proposed. The obtained results suggested that uniaxial tensile strength, uniaxial compressive strength, elastic modulus, and cohesion dramatically decreased with increasing weathering time, characterized as the negative exponential relationship in general. The influences of various weathering grades on fracture behavior of the rock specimens were discussed. The cumulative damage of the rock by the weathering time decreased the friction coefficient of the specimens which led to the initiation and propagation of microcrack within the rock at lower stress conditions. The obtained results improved the understanding of the roles of weathering on the mechanical properties of sedimentary rocks, which is helpful in the design of the underground geotechnical structures.

Effect of Microstructure on Mechanical Properties and Wear Characteristics of Cemented Tungsten Carbides

2009 ◽  
Vol 76-78 ◽  
pp. 609-612 ◽  
Author(s):  
H.Q. Sun ◽  
Rudy Irwan ◽  
Han Huang ◽  
Gwidon W. Stachowiak
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Elastic Modulus ◽  
Friction Coefficient ◽  
Tungsten Carbide ◽  
Removal Rate ◽  
Tungsten Carbides ◽  
Removal Rates ◽  
Wear Characteristics ◽  
Effect Of Microstructure

The effect of microstructure of cemented tungsten carbide materials on their mechanical properties and wear characteristics was investigated using nanoindentation and nanoscratch methods. The results indicated that the variation in grain size insignificantly affected the hardness, elastic modulus and friction coefficient of the work materials, but considerably influenced their removal rates. The carbide with coarser grains exhibited a much higher removal rate was obtained during scratching.

Study on Laser Micro Shock Effect on Electrical Resistivity of Nanometer Copper Film

2014 ◽  
Vol 989-994 ◽  
pp. 45-48
Author(s):  
Qing Xue ◽  
Yin Qun Hua ◽  
Yu Chuan Bai ◽  
Rui Fang Chen ◽  
Hai Xia Liu
Keyword(s):  
Mechanical Properties ◽  
Electrical Resistivity ◽  
Elastic Modulus ◽  
Stress Concentration ◽  
Magnetron Sputtering ◽  
Twin Boundary ◽  
Copper Film ◽  
Electrical Performance ◽  
Shock Processing ◽  
Main Factor

The aim of this research is to improve the electrical performance of the nanometer copper film by laser micro shock processing. The nanometer copper film was prepared by the magnetron sputtering. The mechanism of laser micro shock processing effect on electrical resistivity, hardness and elastic modulus was investigated. The results show that the electrical resistivity of copper film after laser micro shock reduced by 22.5 % on average. And, the hardness and the elastic modulus increased by 38.5 % and 45.2 % on average, respectively. According to our research, we conclude that, the existence of a large number of twin, twin boundary, fault and the grow up grain are the main factor of the improvement of the electrical performance; and the existence of twin, stress concentration holes and fault are the key to improve its mechanical properties.

Mechanical properties of ion-implanted amorphous silicon

2004 ◽  
Vol 19 (1) ◽  
pp. 338-346 ◽  
Author(s):  
D.M. Follstaedt ◽  
J.A. Knapp ◽  
S.M. Myers
Keyword(s):  
Mechanical Properties ◽  
Phase Transition ◽  
Fracture Toughness ◽  
Finite Element ◽  
Elastic Modulus ◽  
Amorphous Silicon ◽  
Microelectromechanical Systems ◽  
Amorphous Structure ◽  
Alternative Material ◽  
Amorphous Si

We used nanoindentation coupled with finite element modeling to determine the mechanical properties of amorphous Si layers formed by self-ion implantation of crystalline Si at approximately 100 K. When the effects of the harder substrate on the response of the layers to indentation were accounted for, the amorphous phase was found to have a Young’s modulus of 136 ± 9 GPa and a hardness of 10.9 ± 0.9 GPa, which were 19% and 10% lower than the corresponding values for crystalline Si. The hardness agrees well with the pressure known to induce a phase transition in amorphous Si to the denser β–Sn-type structure of Si. This transition controls the yielding of amorphous Si under compressive stress during indentation, just as it does in crystalline Si. After annealing 1 h at 500 °C to relax the amorphous structure, the corresponding values increase slightly to 146 ± 9 GPa and 11.6 ± 1.0 GPa. Because hardness and elastic modulus are only moderately reduced with respect to crystalline Si, amorphous Si may be a useful alternative material for components in Si-based microelectromechanical systems if other improved properties are needed, such as increased fracture toughness.

scholarly journals A Research on the Macroscopic and Mesoscopic Parameters of Concrete Based on an Experimental Design Method

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1627
Author(s):  
Hui Su ◽  
Hongliang Li ◽  
Baowen Hu ◽  
Jiaqi Yang
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Friction Coefficient ◽  
Experimental Design ◽  
Significant Influence ◽  
Interfacial Transition Zone ◽  
The Other ◽  
Stiffness Ratio ◽  
Response Surface Design ◽  
Surface Design

Concrete is a composite material that has complex mechanical properties. The mechanical properties of each of its components are different at the mesoscopic scale. Studying the relationship between the macroscopic and mesoscopic parameters of concrete can help better understand its mechanical properties at these levels. When using the discrete element method to model the macro-mesoscopic parameters of concrete, their calibration is the first challenge. This paper proposes a numerical model of concrete using the particle discrete element software particle flow code (PFC). The mesoscopic parameters required by the model need to be set within a certain range for an orthogonal experimental design. We used the proposed model to perform numerical simulations as well as response surface design and analysis. This involved fitting a set of mapping relationships between the macro–micro parameters of concrete. An optimization model was established in the MATLAB environment. The program used to calibrate the mesoscopic parameters of concrete was written using the genetic algorithm, and its macro-micro parameters were inverted. The following three conclusions can be drawn from the orthogonal test: First, the tensile strength and shear strength of the parallel bond between the particles of mortar had a significant influence on the peak compressive strength of concrete, whereas the influence of the other parameters was not significant. Second, the elastic modulus of the parallel bonding between particles of mortar, their stiffness ratio and friction coefficient, and the elastic modulus and stiffness ratio of contact bonding in the interfacial transition zone had a significant influence on the elastic modulus, whereas the influence of the other parameters was not significant. Third, the elastic modulus, stiffness ratio, and friction coefficient of the particles of mortar as well as the ratio of the contact adhesive stiffness in their interfacial transition zone had a significant influence on Poisson’s ratio, whereas the influence of the other parameters was not significant. The fitting effect of the response surface design was good.

Anealing Effect on the Microstructure and Mechanical Properties of LaB6 Films

2013 ◽  
Vol 303-306 ◽  
pp. 2514-2518 ◽  
Author(s):  
Li Jie Hu ◽  
Lin Zhang ◽  
Jie Lin ◽  
Guang Hui Min
Keyword(s):  
Mechanical Properties ◽  
Raman Spectrum ◽  
Elastic Modulus ◽  
Magnetron Sputtering ◽  
Cross Sections ◽  
Annealing Process ◽  
Dc Magnetron Sputtering ◽  
Microstructure And Mechanical Properties ◽  
Negative Effect ◽  
Deposited Films

Lathanum hexaboride films were deposited by dc magnetron sputtering with the same sputtering parameters. AFM, XRD, Raman spectrum was used to characterize the film. The as-deposited films were annealed at 400 oC, 500 oC and 600 oC, respectively. After 400 oC’s annealing, morphology of fracture cross-sections of the films exhibited evolutions from columnar to the equiaxial, and the crystallinity of the film was improved as well. It was also found annealing process generated negative effect on the film’s hardness and elastic modulus.

EFFECT OF SUBSTRATE TEMPERATURE ON MICROSTRUCTURE AND WEAR BEHAVIOR OF MAGNETRON SPUTTERED CrCuN FILMS

2013 ◽  
Vol 20 (06) ◽  
pp. 1350061
Author(s):  
SHUYONG TAN ◽  
XUHAI ZHANG ◽  
YAN ZHANG ◽  
JIANQING JIANG
Keyword(s):  
Wear Resistance ◽  
Friction Coefficient ◽  
Wear Rate ◽  
Magnetron Sputtering ◽  
Substrate Temperature ◽  
Wear Behavior ◽  
Dc Magnetron Sputtering ◽  
Wear Performance ◽  
Preferential Growth ◽  
Substrate Temperatures

CrCuN films were deposited under different substrate temperatures by direct current (DC) magnetron sputtering. The structure and wear resistance of the films were then studied. The substrate temperature has almost no effect on the film composition, phase constitution and preferred orientation. The CrCuN films have 3 at.% Cu and consist of CrN phases with CrN (200) preferential growth independent of the substrate temperature. But a strong effect of the substrate temperature on the wear behavior is noticed. The film prepared under the substrate temperature of 100°C has the best wear performance. Its friction coefficient and wear rate are 0.1 and 6.6 × 10-6 mm3/Nm, respectively.

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.

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