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

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.

2010 ◽  
Vol 123-125 ◽  
pp. 1135-1138 ◽  
Author(s):  
Yeon Hee Lee ◽  
Hitoshi Takagi ◽  
Kazuya Ohkita ◽  
Han Ki Yoon

. This paper deals with the mechanical characterization of short bamboo fiber reinforced green composites (BFGC). The effects of thermal shock on the mechanical properties of BFGC were investigated. Their flexural strength was evaluated by 3-point bending test, and Vickers hardness and elastic modulus were evaluated by a nano-indentation method. The fracture surfaces and microstructure of BFGC were examined by SEM. The results of evaluated mechanical properties (3-point bending test) after thermal shock indicated that the strength of BFGC decreased below 40°C, however the strength became constant above 40°C. The Vickers hardness and modulus of elasticity evaluated from the nano-indentation tests also represented a similar trend to that of flexural strength. The fracture surface of thermal shocked BFGC after bending tests indicated the pull-outed bamboo fibers. This might be responsible for insufficient bonding between bamboo fiber and resin.


2008 ◽  
Vol 591-593 ◽  
pp. 436-440
Author(s):  
João Marcos K. Assis ◽  
Francisco Piorino Neto ◽  
Francisco Cristóvão Lourenço de Melo ◽  
Maria do Carmo de Andrade Nono

A comparative study between alumina added niobia ceramics and two alumina zirconia composites from nanostructured TZP (7% and 14% weight) was made. On this composites the zirconia were yttria stabilized and the alumina were submicron structured. As sintering aid a mixture of magnesia, niobia and talc were used on all samples. The sintering was performed at 1450 oC during 60 minutes. The characteristic grain size and shape of an alumina and zirconia powders, aggregates and agglomerates were characterized. The sintering ceramics were evaluated through hardness, fracture toughness and 4 point bending test. Weibull statistic was applied on the flexural results. Although the fracture toughness result from ZTA were lower, and seems to be affected by the liquid fase, the hardness and Weibull modulus were higher than alumina niobia. The grains size and the homogeneity of its distributions on the microstructure of this ceramics was correlated to these higher values. The results from these alumina zirconia composites showed a potential to apply as a ballistic armor material.


2021 ◽  
Vol 13 (10) ◽  
pp. 5494
Author(s):  
Lucie Kucíková ◽  
Michal Šejnoha ◽  
Tomáš Janda ◽  
Jan Sýkora ◽  
Pavel Padevět ◽  
...  

Heating wood to high temperature changes either temporarily or permanently its physical properties. This issue is addressed in the present contribution by examining the effect of high temperature on residual mechanical properties of spruce wood, grounding on the results of full-scale fire tests performed on GLT beams. Given these tests, a computational model was developed to provide through-thickness temperature profiles allowing for the estimation of a charring depth on the one hand and on the other hand assigning a particular temperature to each specimen used subsequently in small-scale tensile tests. The measured Young’s moduli and tensile strengths were accompanied by the results from three-point bending test carried out on two groups of beams exposed to fire of a variable duration and differing in the width of the cross-section, b=100 mm (Group 1) and b=160 mm (Group 2). As expected, increasing the fire duration and reducing the initial beam cross-section reduces the residual bending strength. A negative impact of high temperature on residual strength has also been observed from simple tensile tests, although limited to a very narrow layer adjacent to the charring front not even exceeding a typically adopted value of the zero-strength layer d0=7 mm. On the contrary, the impact on stiffness is relatively mild supporting the thermal recovery property of wood.


2017 ◽  
Vol 1 (7) ◽  
Author(s):  
Irene Lucas ◽  
Pilar Jiménez-Cavero ◽  
J. M. Vila-Fungueiriño ◽  
Cesar Magén ◽  
Soraya Sangiao ◽  
...  

2013 ◽  
Vol 486 ◽  
pp. 283-288
Author(s):  
Ladislav Fojtl ◽  
Soňa Rusnáková ◽  
Milan Žaludek

This research paper deals with an investigation of the influence of honeycomb core compression on the mechanical properties of sandwich structures. These structures consist of prepreg facing layers and two different material types of honeycomb and are produced by modified compression molding called Crush-Core technology. Produced structures are mechanically tested in three-point bending test and subjected to low-velocity impact and Charpy impact test.


2010 ◽  
Vol 177 ◽  
pp. 447-450 ◽  
Author(s):  
Xin Zhang ◽  
Yi Wen Hu ◽  
Yin Wu ◽  
Wen Jie Si

The purpose of this study was to evaluate the crystal phase formation behavior and its influence on the mechanical properties of LiO2-SiO2-P2O5 glass-ceramics system. High temperature XRD was used to analyze the crystal phase formation in situ. The crystalline phases in the material both before and after heat-treatment were also analyzed. The flexural strength was measured by three-point bending test according to ISO 6872:2008(E). The SEM analysis showed that the high strength of the glass-ceramics is attributed to the continuous interlocking microstructure with fine lithium disilicate crystallines.


1997 ◽  
pp. 211-220
Author(s):  
Yuzou Kuriyagawa ◽  
Shyouichi Akiba ◽  
Tetsukazu Kida ◽  
Sumio G. Nomachi

2013 ◽  
Vol 746 ◽  
pp. 394-399
Author(s):  
Niwat Anuwongnukroh ◽  
Yosdhorn Chuankrerkkul ◽  
Surachai Dechkunakorn ◽  
Pornkiat Churnjitapirom ◽  
Theeralaksna Suddhasthira

The archwire is generally used in fixed appliances for orthodontic treatment to correct dental malocclusion. However, it is interesting to know whether general purpose stainless steel wire could replace commercial orthodontic archwire in orthodontic practice for economic reasons. The purpose of this study was to determine the bending properties of general purpose stainless steel wire compared with commercial orthodontic stainless steel wires after forming as an archwire for orthodontic use. The samples used in this study were 90 general purpose and 45 commercial (Highland) round stainless steel wires in 0.016, 0.018, and 0.020 sizes (30 general purpose and 15 commercial wires for each size). All 15 general purpose stainless steel wires with different sizes were formed into orthodontic archwire with a Universal Testing Machine. All samples were tested (three-point bending test) for mechanical properties. The results showed no significant difference between general purpose and commercial orthodontic wires in size 0.016 for 0.1 mm offset bending force, 0.2% yield strength, and springback. Although many mechanical properties of general purpose wires differed from commercial wires, their values conformed to other previous studies within the range of clinical acceptance. In conclusion, orthodontic formed general purpose round stainless steel wires had statistically different (p <0.05) mechanical properties from commercial orthodontic stainless steel wires (Highland) but the mechanical properties were acceptable to use in orthodontic treatment.


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