Nano Mechanical Behaviors of Hindleg Cuticle in Beetle Dorcus titanus (Coleoptera: Lucanidae)

2013 ◽  
Vol 668 ◽  
pp. 529-533
Author(s):  
Zhi Xian Yang ◽  
Ze Hua Liu ◽  
C. Guo ◽  
Zhen Dong Dai
Keyword(s):  
Mechanical Properties ◽  
Hierarchical Structure ◽  
Biological Materials ◽  
Mechanical Behaviors ◽  
Formation Factor ◽  
Hierarchical Materials ◽  
Nano Indentation ◽  
Engineering Materials ◽  
Different Thickness ◽  
Strength And Toughness

Biomaterials have a hierarchical structure with outstanding mechanical properties that are far beyond those additional engineering materials. Nano indentation techniques are convenient to study the biological materials. In this paper, the nano mechanical behavors of hindleg cuticle in beetle Dorcus titanus were investigated. The results indicate that the hardness and modulus values of hindleg cuticle outside are far higher than that of inside as well as the front podomere cuticle outside has a softer stiffness than that of the middle podomere cuticle outside, which is exactly contrary to the cuticle inside anyway. The primary formation factor probably is related to the different epicuticle and exocuticle with different thickness. Mechanics theories on the stiffness, hardness, strength and toughness of biomaterials can be expected to play a key role in developing bio-inspired multi-functional and hierarchical materials in future.

Surface Texture and Mechanical Behavior of Claw Material in Beetle Dorcus titanus (Coleoptera: Lucanidae)

2013 ◽  
Vol 461 ◽  
pp. 305-312 ◽  
Author(s):  
Zhi Xian Yang ◽  
Ze Hua Liu ◽  
Zhen Dong Dai
Keyword(s):  
Mechanical Properties ◽  
Mechanical Behavior ◽  
Hierarchical Structure ◽  
Surface Texture ◽  
Smooth Surface ◽  
Biological Materials ◽  
Industrial Products ◽  
Biomimetic Materials ◽  
Nanomechanical Properties ◽  
Synthetic Materials

Biomaterials have an integrated, hierarchical structure with outstanding mechanical properties which are far beyond those achieved by using the same synthetic materials. nanoindentation techniques have recently been adapted for studying the biological materials. In this paper, the surface texture and nanomechanical properties of claw material in beetle Dorcus titanus were investigated. It is founded that the claw possesses of an optimized shape as well as the non-smooth surface texture with many stripes like as the fullows close to the arc inside. The results of nanoindentation tests indicate that the modulus value of the claw cuticle near the tip (11.25±0.57 GPa) is over three times larger than that near the claw root (3.61±0.22 GPa) and there is an incremental hardness and modulus values from the claw root to the tip. Quantitive measurements on the nanomechanical properties of claw material could help to develop biomimetic materials suitable for industrial products.

Fractals to Model Hierarchical Biomaterials

2008 ◽  
Vol 58 ◽  
pp. 54-59 ◽  
Author(s):  
Alberto Carpinteri ◽  
Pietro Cornetti ◽  
Nicola Maria Pugno ◽  
Alberto Sapora
Keyword(s):  
Mechanical Properties ◽  
Hierarchical Structure ◽  
Length Scale ◽  
Primary Concern ◽  
New Materials ◽  
New Model ◽  
Hierarchical Materials ◽  
Fractal Approach ◽  
Recursive Formulas ◽  
Strength And Stiffness

Many biological materials exhibit a hierarchical structure over more than one length scale. Understanding how hierarchy affects their mechanical properties emerges as a primary concern, since it can guide the synthesis of new materials to be tailored for specific applications. In this paper the strength and stiffness of hierarchical materials are investigated by means of a fractal approach. A new model is proposed, based both on geometric and material considerations and involving simple recursive formulas.

Grain Size Effect on Mechanical Behavior of Nanocrystalline Alloy Films

2017 ◽  
Vol 48 ◽  
pp. 204-210
Author(s):  
Bing Yang Ma ◽  
Kai Cheng Shi ◽  
Hai Long Shang ◽  
Jin Yan Qi ◽  
Rong Bn Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Nanocrystalline Alloy ◽  
Nanocrystalline Alloys ◽  
Grain Size Effect ◽  
Mechanical Behaviors ◽  
Multilayered Films ◽  
Grain Sizes ◽  
Pure Metals ◽  
Different Thickness

The effect of grain size in nanocrystalline alloys is difficult to analyze because challenges of controlling a number of other microstructure factors. This paper designed and prepared a series of multilayered films with Al-Zr crystalline layers of different thickness but with amorphous layers of identical thickness. In these multilayered films, the heights of columnar crystals in crystalline layers were controlled from 5 to 160 nm and their diameters were kept at 10 to 15 nm, independent of their heights. This design achieved the control of grain size, independent from other microstructure factors. The analysis of mechanical properties of these multilayered films showed that the inverse Hall-Petch phenomenon also exists in Al-Zr nanocrystalline alloys. The critical grain sizes of deviation from the Hall-Petch relationship and the inverse Hall-Petch phenomenon are approximately 40 nm and 10 nm respectively. These mechanical behaviors of nanocrystalline alloys are similar to those reported in pure metals.

Microstructure and Mechanical Properties of ZrB2/h-BN Multiphase Ceramics by Low-Temperature Reactive Sintering

2016 ◽  
Vol 697 ◽  
pp. 510-514 ◽  
Author(s):  
Feng Rui Zhai ◽  
Ke Shan ◽  
Ruo Meng Xu ◽  
Min Lu ◽  
Zhong Zhou Yi ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Relative Density ◽  
Fracture Strength ◽  
Solid Phase ◽  
Raw Materials ◽  
Solid Phase Reaction ◽  
Phase Reaction ◽  
Microstructure And Mechanical Properties ◽  
Multiphase Ceramics ◽  
Strength And Toughness

In the present paper, the ZrB2/h-BN multiphase ceramics were fabricated by SPS (spark plasma sintering) technology at lower sintering temperature using h-BN, ZrO2, AlN and Si as raw materials and B2O3 as a sintering aid. The phase constitution and microstructure of specimens were analyzed by XRD and SEM. Moreover, the effects of different sintering pressures on the densification, microstructure and mechanical properties of ZrB2/h-BN multiphase ceramics were also systematically investigated. The results show that the ZrB2 was obtained through solid phase reaction at different sintering pressures, and increasing sintering pressure could accelerate the formation of ZrB2 phase. As the sintering pressure increasing, the fracture strength and toughness of the sintered samples had a similar increasing tendency as the relative density. The better comprehensive properties were obtained at given sintering pressure of 50MPa, and the relative density, fracture strength and toughness reached about 93.4%, 321MPa and 3.3MPa·m1/2, respectively. The SEM analysis shows that the h-BN grains were fine and uniform, and the effect of sintering pressure on grain size was inconspicuous. The distribution of grain is random cross array, and the fracture texture was more obvious with the increase of sintering pressure. The fracture mode of sintered samples remained intergranular fracture mechanism as sintering pressure changed, and the grain refinement, grain pullout and crack deflection helped to increase the mechanical properties.

scholarly journals Properties of High-Strength Flowable Mortar Reinforced with Palm Fibers

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Eethar Thanon Dawood ◽  
Mahyuddin Ramli
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Physical And Mechanical Properties ◽  
High Strength ◽  
Test Results ◽  
Palm Fiber ◽  
Toughness Index ◽  
Strength And Toughness

This study was conducted to determine some physical and mechanical properties of high-strength flowable mortar reinforced with different percentages of palm fiber (0, 0.2, 0.4, 0.6, 0.8, 1.0, 1.2, 1.4, and 1.6% as volumetric fractions). The density, compressive strength, flexural strength, and toughness index were tested to determine the mechanical properties of this mortar. Test results illustrate that the inclusion of this fiber reduces the density of mortar. The use of 0.6% of palm fiber increases the compressive strength and flexural strength by about 15.1%, and 16%, respectively; besides, the toughness index (I5) of the high-strength flowable mortar has been significantly enhanced by the use of 1% and more of palm fiber.

Measurement of Young's Modulus and Poisson's Ratio of Thin Film by Combination of Bulge Test and Nano-Indentation

2008 ◽  
Vol 33-37 ◽  
pp. 969-974 ◽  
Author(s):  
Bong Bu Jung ◽  
Seong Hyun Ko ◽  
Hun Kee Lee ◽  
Hyun Chul Park
Keyword(s):  
Thin Film ◽  
Mechanical Properties ◽  
Young’S Modulus ◽  
Poisson’S Ratio ◽  
Young's Modulus ◽  
Applied Pressure ◽  
Indentation Test ◽  
Poisson's Ratio ◽  
Bulge Test ◽  
Nano Indentation

This paper will discuss two different techniques to measure mechanical properties of thin film, bulge test and nano-indentation test. In the bulge test, uniform pressure applies to one side of thin film. Measurement of the membrane deflection as a function of the applied pressure allows one to determine the mechanical properties such as the elastic modulus and the residual stress. Nano-indentation measurements are accomplished by pushing the indenter tip into a sample and then withdrawing it, recording the force required as a function of position. . In this study, modified King’s model can be used to estimate the mechanical properties of the thin film in order to avoid the effect of substrates. Both techniques can be used to determine Young’s modulus or Poisson’s ratio, but in both cases knowledge of the other variables is needed. However, the mathematical relationship between the modulus and Poisson's ratio is different for the two experimental techniques. Hence, achieving agreement between the techniques means that the modulus and Poisson’s ratio and Young’s modulus of thin films can be determined with no a priori knowledge of either.

Modelling the nano indentation behaviour of recast layer and heat affected zone on reverse micro EDMed hemispherical feature

2021 ◽  
pp. 1-15
Author(s):  
Tribeni Roy ◽  
Anuj Sharma ◽  
Prabhat Ranjan ◽  
R. Balasubramaniam
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Heat Affected Zone ◽  
Parent Material ◽  
Recast Layer ◽  
Machined Surface ◽  
Nano Indentation ◽  
Fea Simulation ◽  
Load Displacement ◽  
Good Agreement

Abstract Electrical discharge machined surfaces inherently possess recast layer on the surface with heat affected zone (HAZ) beneath it and these have a detrimental effect on the mechanical properties viz. hardness, elastic modulus, etc. It is very difficult to experimentally characterise each machined surface. Therefore, an attempt is made in this study to numerically calculate the mechanical properties of the parent material, HAZ and the recast layer on a hemispherical protruded micro feature fabricated by reverse micro EDM (RMEDM). In the 1st stage, nano indentation was performed to experimentally determine the load-displacement plots, elastic modulus and hardness of the parent material, HAZ and the recast layer. In the 2nd stage, FEA simulation was carried out to mimic the nano indentation process and determine the load-displacement plots for all the three cases viz. parent material, recast layer and HAZ. Results demonstrated that the load'displacement plots obtained from numerical model in each case was in good agreement with that of the experimental curves. Based on simulated load-displacement plots, hardness was also calculated for parent material, HAZ and the recast layer. A maximum of 11% error was observed between simulated values of hardness and experimentally determined values.

scholarly journals An Exploratory Investigation of the Mechanical Properties of the Nanostructured Porous Materials Deposited by Laser-Induced Chemical Solution Synthesis

2017 ◽  
Vol 5 (2) ◽  
Author(s):  
Cheng Peng ◽  
C. Richard Liu ◽  
Rohit Voothaluru ◽  
Chun-Yu Ou ◽  
Zhikun Liu
Keyword(s):  
Mechanical Properties ◽  
Porous Materials ◽  
Nanostructured Materials ◽  
Bending Test ◽  
Porous Coating ◽  
Coating Film ◽  
Statistical Regression ◽  
Chemical Solution ◽  
Solution Synthesis ◽  
Nano Indentation

Laser-induced chemical solution synthesis has been recently developed as a new generic method to create porous nanostructured materials for complex and miniaturized devices. The material made by this approach is successfully demonstrated for electrochemical catalytic, nanoscale powders, protective coatings, and other applications. One question has therefore been raised: What are the mechanical properties of the porous materials deposited by the laser-induced chemical solution synthesis? This paper has attempted to explore the mechanical properties of such porous nanostructured materials deposited by this new nanomanufacturing method. This process also offers an innovative opportunity to study the strength of a very simple bonding in additive manufacturing. A thin-film of copper nanoparticles is deposited on copper substrates; then, the microstructure of the deposited film is characterized by scanning electron microscope (SEM), and mechanical properties are investigated by a variety of experiments, such as microhardness test, nano-indentation test, bending test, and adhesion test. The mechanical properties of substrates with surface deposition have been shown to have adequate bond strength (>60 g/mm) to allow effective usage in intended applications. Based on the test results, statistical regression and significant tests have also been carried out. A new model for the nano-indentation of the porous coating (film) is proposed. The empirical results have shown that the effect of coating thickness is more prominent on mechanical properties in the case of thick coating deposition.

scholarly journals Simultaneous Enhancement of Strength and Toughness of PLA Induced by Miscibility Variation with PVA

Polymers ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1178 ◽  
Author(s):  
Yanping Liu ◽  
Hanghang Wei ◽  
Zhen Wang ◽  
Qian Li ◽  
Nan Tian
Keyword(s):  
Mechanical Properties ◽  
High Performance ◽  
Fracture Strain ◽  
Electrospun Fiber ◽  
Structural Evolution ◽  
Amorphous Structure ◽  
Poly Lactic Acid ◽  
Poly Vinyl Alcohol ◽  
Scanning Calorimetry ◽  
Strength And Toughness

The mechanical properties of poly (lactic acid) (PLA) nanofibers with 0%, 5%, 10%, and 20% (w/w) poly (vinyl alcohol) (PVA) were investigated at the macro- and microscale. The macro-mechanical properties for the fiber membrane revealed that both the modulus and fracture strain could be improved by 100% and 70%, respectively, with a PVA content of 5%. The variation in modulus and fracture strain versus the diameter of a single electrospun fiber presented two opposite trends, while simultaneous enhancement was observed when the content of PVA was 5% and 10%. With a diameter of 1 μm, the strength and toughness of the L95V5 and L90V10 fibers were enhanced to over 3 and 2 times that of pure PLA, respectively. The structural evolution of electrospun nanofiber was analyzed by differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR). Although PLA and PVA were still miscible in the concentration range used, the latter could crystallize independently after electrospinning. According to the crystallization behavior of the nanofibers, a double network formed by PLA and PVA—one microcrystal/ordered structure and one amorphous structure—is proposed to contribute to the simultaneous enhancement of strength and toughness, which provides a promising method for preparing biodegradable material with high performance.

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