532 Microstructure and Mechanical Properties in Three-Dimensional Hollow Knitted Fabric Composite

2010 ◽  
Vol 2010.18 (0) ◽  
pp. _532-1_-_532-3_
Author(s):  
Kei URUMA ◽  
Shinji OGIHARA ◽  
Asami NAKAI
Author(s):  
Hongyan Qi ◽  
Guixiong Gao ◽  
Huixin Wang ◽  
Yunhai Ma ◽  
Hubiao Wang ◽  
...  

The naked mole rat incisors (NMRI) exhibit excellent mechanical properties, which makes it a good prototype for design and fabrication of bionic mechanical systems and materials. In this work, we characterized the chemical composition, microstructure and mechanical properties of NMRI, and further compared these properties with the laboratory rat incisors (LRI). We found that (1) Enamel and dentin are composed of organic matter, inorganic matter and water. The ratio of Ca/P in NMRI enamel is higher than that of LRI enamel. (2) The dentin has a porous structure. The enamel has a three-dimensional reticular structure, which is more complex, regular and denser than the lamellar structure of LRI enamel. (3) Enamel has anisotropy. Its longitudinal nano-hardness is greater than that of transverse nano-hardness, and both of them are higher than that of LRI enamel. Their nano-hardness and elastic modulus increase with the increment of distance from the enamel-dentin boundary. The nano-hardness of dentin is smaller than that of enamel. The chemical composition and microstructure are considered to be the reasons for the excellent properties of NMRI. The chemical composition and unique microstructure can provide inspiration and guidelines for the design of bionic machinery and materials.


1993 ◽  
Vol 59 (566) ◽  
pp. 2323-2330 ◽  
Author(s):  
Akihiro Fujita ◽  
Hiroyuki Hamada ◽  
Zenichiro Maekawa ◽  
Etsuji Ohno

2021 ◽  
Vol 2077 (1) ◽  
pp. 012012
Author(s):  
R Mendagaliyev ◽  
O G Klimova-Korsmik ◽  
S Y Ivanov ◽  
K D Babkin ◽  
A M Vildanov

Abstract The formation of microstructure features of cold-resistant bainite-martensite steel 09CrNi2MoCu has been investigated. Thermal cycles during direct laser deposition were studied. The thermal cycles at different points of the deposited samples were investigated. The thermal cycles and CCT diagrams on microstructure formation and mechanical properties have been analyzed. The numerical calculation of the three-dimensional thermal conductivity problem by the finite element method is carried out. The received data of experimentally measured thermal cycles and the calculated data have shown good coincidence of temperature values. On the basis of the obtained data the calculated dependence of inter-layer temperature at depositing the sample with and without a pause is given. The microstructure and mechanical properties of the samples in the initial state and after heat treatment have been studied and compared with traditional hot rolling. The microstructure features at different pauses between passes in different parts of the obtained samples were revealed. The effect on static tensile and impact toughness at -40°C in the bred and heat-treated state was investigated.


2016 ◽  
Vol 87 (7) ◽  
pp. 853-864 ◽  
Author(s):  
Arif Kurbak

In this work, based on the geometrical model given in Part I, a mechanical model is created for dry relaxed slack plain knitted technical fabrics including the three-dimensional friction effects. The equilibrium of forces and moments applied on a loop are written by using the elasticity theory of thin rods. Through this model, it is shown that a dry relaxed plain knitted fabric can be in a stable state induced by friction. The application of the model was carried out on E-glass technical fabric, which was also used in Part I as its dimensional properties were obtained through the created geometrical model. In the current part, Part II, the mechanical properties of this fabric are obtained and discussed as an exemplary application.


2020 ◽  
Vol 143 (2) ◽  
Author(s):  
Pradeep Kumar Krishnan ◽  
Ramanathan Arunachalam ◽  
Afzal Husain ◽  
Majid Al-Maharbi

Abstract In the present work, the influence of stirrer blade design on the dispersion of reinforcement particles in the aluminum metal matrix was studied extensively through experiments and also simulated them using the computational fluid dynamics (CFD) method. The microstructure and mechanical properties of the produced metal matrix composites (MMCs) were studied. The analysis of the microstructure was performed using an optical microscope to visualize the reinforcement distribution and binding within the matrix. Further, field emission scanning electron microscope (FESEM) and X-ray diffraction (XRD) were used to characterize the MMCs. The experimental density was assessed using the Archimedes method, and the theoretical density was determined using the mixture law to determine the percentage of porosity in the MMCs. Hardness, compression, and tensile testing were performed on the produced samples. A three-dimensional computational method was used to predict the flow field of aluminum melt and study the influence of the blade design on the distribution of the reinforcement. Experimental results validated the CFD recommendation on the blade design. The CFD recommendation was based on the structure, power number, and the number of blades, and accordingly, the four-blade flat stirrer (B4) design was the best. The experimental results also corroborated the CFD recommendation with the four-blade flat stirrer design achieving the highest compressive strength (642 MPa), highest hardness (45 HRB), and highest tensile strength (206 MPa) among the five different blade designs investigated.


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